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Sample records for metal-organic frameworks mofs

  1. Metal Organic Frameworks (MOFs)

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 11. Molecule Matters - Metal Organic Frameworks (MOFs). R Sarvanakumar S Sankararaman. Feature Article Volume 12 Issue 11 November 2007 pp 77-86. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. Molecule Matters-Metal Organic Frameworks (MOFs)

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 11. Molecule Matters - Metal Organic Frameworks (MOFs). R Sarvanakumar S Sankararaman ... Author Affiliations. R Sarvanakumar1 S Sankararaman1. Department of Chemistry, Indian Institute of Technology, Madras, Chennai 600036, India.

  3. The relevance of metal organic frameworks (MOFs)

    Indian Academy of Sciences (India)

    The metal organic frameworks (MOFs) have evolved to be an important family and a corner stone for research in the area of inorganic chemistry. The progress made since 2000 has attracted researchers from other disciplines to actively engage themselves in this area. This cooperative synergy of different scientific believes ...

  4. Enzyme-MOF (metal-organic framework) composites.

    Science.gov (United States)

    Lian, Xizhen; Fang, Yu; Joseph, Elizabeth; Wang, Qi; Li, Jialuo; Banerjee, Sayan; Lollar, Christina; Wang, Xuan; Zhou, Hong-Cai

    2017-06-06

    The ex vivo application of enzymes in various processes, especially via enzyme immobilization techniques, has been extensively studied in recent years in order to enhance the recyclability of enzymes, to minimize enzyme contamination in the product, and to explore novel horizons for enzymes in biomedical applications. Possessing remarkable amenability in structural design of the frameworks as well as almost unparalelled surface tunability, Metal-Organic Frameworks (MOFs) have been gaining popularity as candidates for enzyme immobilization platforms. Many MOF-enzyme composites have achieved unprecedented results, far outperforming free enzymes in many aspects. This review summarizes recent developments of MOF-enzyme composites with special emphasis on preparative techniques and the synergistic effects of enzymes and MOFs. The applications of MOF-enzyme composites, primarily in transferation, catalysis and sensing, are presented as well. The enhancement of enzymatic activity of the composites over free enzymes in biologically incompatible conditions is emphasized in many cases.

  5. The relevance of metal organic frameworks (MOFs) in inorganic ...

    Indian Academy of Sciences (India)

    Vol. 124, No. 2, March 2012, pp. 339–353. c Indian Academy of Sciences. The relevance of metal organic frameworks (MOFs) in inorganic materials chemistry. SRINIVASAN NATARAJAN. ∗ .... preparing inorganic coordination compounds such as: .... (c) The connectivity between the heptanuclear cobalt cluster and the.

  6. The relevance of metal organic frameworks (MOFs) in inorganic ...

    Indian Academy of Sciences (India)

    The metal organic frameworks (MOFs) have evolved to be an important family and a corner stone for research in the area of inorganic chemistry. The progress made since 2000 has attracted researchers from other disciplines to actively engage themselves in this area. This cooperative synergy of different scientific believes ...

  7. Metal Organic Frameworks: Explorations and Design Strategies for MOF Synthesis

    KAUST Repository

    AbdulHalim, Rasha

    2016-11-27

    Metal-Organic Frameworks (MOFs) represent an emerging new class of functional crystalline solid-state materials. In the early discovery of this now rapidly growing class of materials significant challenges were often encountered. However, MOFs today, with its vast structural modularity, reflected by the huge library of the available chemical building blocks, and exceptional controlled porosity, stand as the most promising candidate to address many of the overbearing societal challenges pertaining to energy and environmental sustainability. A variety of design strategies have been enumerated in the literature which rely on the use of predesigned building blocks paving the way towards potentially more predictable structures. The two major design strategies presented in this work are the molecular building block (MBB) and supermolecular building block (SBB) -based approaches for the rationale assembly of functional MOF materials with the desired structural features. In this context, we targeted two highly connected MOF platforms, namely rht-MOF and shp-MOF. These two MOF platforms are classified based on their topology, defined as the underlying connectivity of their respective net, as edge transitive binodal nets; shp being (4,12)-connected net and rht being (3,24)-connected net. These highly connected nets were deliberately targeted due to the limited number of possible nets for connecting their associated basic building units. Two highly porous materials were designed and successfully constructed; namely Y-shp-MOF-5 and rht-MOF-10. The Y-shp-MOF-5 features a phenomenal water stability with an exquisite behavior when exposed to water, positioning this microporous material as the best adsorbent for moisture control applications. The shp-MOF platform proved to be modular to ligand functionalization and thus imparting significant behavioral changes when hydrophilic and hydrophobic functionalized ligands were introduced on the resultant MOF. On the other hand, rht-MOF

  8. Peptide assembly-driven metal-organic framework (MOF) motors for micro electric generators.

    Science.gov (United States)

    Ikezoe, Yasuhiro; Fang, Justin; Wasik, Tomasz L; Uemura, Takashi; Zheng, Yongtai; Kitagawa, Susumu; Matsui, Hiroshi

    2015-01-14

    Peptide-metal-organic framework (Pep-MOF) motors, whose motions are driven by anisotropic surface tension gradients created via peptide self-assembly around frameworks, can rotate microscopic rotors and magnets fast enough to generate an electric power of 0.1 μW. A new rigid Pep-MOF motor can be recycled by refilling the peptide fuel into the nanopores of the MOF. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Modulated synthesis of zirconium-metal organic framework (Zr-MOF) for hydrogen storage applications

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2014-01-01

    Full Text Available A modulated synthesis of Zr-metal organic framework (Zr-MOF) with improved ease of handling and decreased reaction time is reported to yield highly crystalline Zr-MOF with well-defined octahedral shaped crystals for practical hydrogen storage...

  10. Teoretické studium vlastností materiálů MOF (Metal Organic Framework)

    OpenAIRE

    Hezinová, Markéta

    2013-01-01

    Metal-Organic Frameworks (MOFs) with coordinatively unsaturated sites (cus's) have shown very good adsorption properties for Sulphur-containing aromatic compounds. One of the promising applications of MOFs currently under investigation is their use in the separation of sulphur-containing compounds from various hydrocarbons. A theoretical investigation of thiophene, dibenzothiophene (DBT) and toluene adsorption on CPO-27(X) and CuBTC MOFs, and NaY zeolite (Si/Al ratio 2.7:1) is presented. The ...

  11. Zirconium-Based metal organic framework (Zr-MOF) material with high hydrostability for hydrogen storage applications

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2013-09-01

    Full Text Available Material-based solutions, such as metal organic frameworks (MOFs), continue to attract increasing attention as viable options for hydrogen storage applications. MOFs are widely regarded as promising materials for hydrogen storage due to their high...

  12. 2-periodic metal-organic frameworks (MOFs) as supermolecular building layers (SBLs) for making targeted 3-periodic MOFs

    KAUST Repository

    Eddaoudi, Mohamed

    2015-09-22

    Embodiments of the present disclosure provide for chemical assemblies, multidimensional metal-organic frameworks (MOFs), supermolecular building layers (SBLs), inorganic molecular building blocks (MBBs), organic MBBs (designed ligands), methods of making each, and methods of using each, and the like. In an embodiment, the composition can be used in catalysis, separations, gas storage, and drug delivery.

  13. Metal organic framework synthesis in the presence of surfactants : Towards hierarchical MOFs?

    NARCIS (Netherlands)

    Seoane, B.; Dikhtiarenko, A.; Mayoral, A.; Tellez, C.; Coronas, J.; Kapteijn, F.; Gascon, J.

    2015-01-01

    The effect of synthesis pH and H2O/EtOH molar ratio on the textural properties of different aluminium trimesate metal organic frameworks (MOFs) prepared in the presence of the well-known cationic surfactant cetyltrimethylammonium bromide (CTAB) at 120 °C was studied with the purpose of obtaining a

  14. A Review on Breathing Behaviors of Metal-Organic-Frameworks (MOFs for Gas Adsorption

    Directory of Open Access Journals (Sweden)

    Mays Alhamami

    2014-04-01

    Full Text Available Metal-organic frameworks (MOFs are a new class of microporous materials that possess framework flexibility, large surface areas, “tailor-made” framework functionalities, and tunable pore sizes. These features empower MOFs superior performances and broader application spectra than those of zeolites and phosphine-based molecular sieves. In parallel with designing new structures and new chemistry of MOFs, the observation of unique breathing behaviors upon adsorption of gases or solvents stimulates their potential applications as host materials in gas storage for renewable energy. This has attracted intense research energy to understand the causes at the atomic level, using in situ X-ray diffraction, calorimetry, Fourier transform infrared spectroscopy, and molecular dynamics simulations. This article is developed in the following order: first to introduce the definition of MOFs and the observation of their framework flexibility. Second, synthesis routes of MOFs are summarized with the emphasis on the hydrothermal synthesis, owing to the environmental-benign and economically availability of water. Third, MOFs exhibiting breathing behaviors are summarized, followed by rationales from thermodynamic viewpoint. Subsequently, effects of various functionalities on breathing behaviors are appraised, including using post-synthetic modification routes. Finally, possible framework spatial requirements of MOFs for yielding breathing behaviors are highlighted as the design strategies for new syntheses.

  15. Review on the current practices and efforts towards pilot-scale production of metal-organic frameworks (MOFs)

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2017-12-01

    Full Text Available Metal-organic frameworks (MOFs) have been under development over the past 20 years. Similar to other technologies, research on MOFs in the upcoming 30 years will move towards the direction where MOF materials can deliver societal benefits by solving...

  16. Metal-Organic Frameworks (MOFs) as Sandwich Coating Cushion for Silicon Anode in Lithium Ion Batteries.

    Science.gov (United States)

    Han, Yuzhen; Qi, Pengfei; Zhou, Junwen; Feng, Xiao; Li, Siwu; Fu, Xiaotao; Zhao, Jingshu; Yu, Danni; Wang, Bo

    2015-12-09

    A novel metal-organic framework (MOF) sandwich coating method (denoted as MOF-SC) is developed for hybrid Li ion battery electrode preparation, in which the MOF films are casted on the surface of a silicon layer and sandwiched between the active silicon and the separator. The obtained electrodes show improved cycling performance. The areal capacity of the cheap and readily available microsized Si treated with MOF-SC can reach 1700 μAh cm(-2) at 265 μA cm(-2) and maintain at 850 μAh cm(-2) after 50 cycles. Beyond the above, the commercial nanosized Si treated by MOF-SC also shows greatly enhanced areal capacity and outstanding cycle stability, 600 μAh cm(-2) for 100 cycles without any apparent fading. By virtue of the novel structure prepared by the MOFs, this new MOF-SC structure serves as an efficient protection cushion for the drastic volume change of silicon during charge/discharge cycles. Furthermore, this MOF layer, with large pore volume and high surface area, can adsorb electrolyte and allow faster diffusion of Li(+) as evidenced by decreased impedance and improved rate performance.

  17. Water-Based Assembly of Polymer-Metal Organic Framework (MOF) Functional Coatings

    Energy Technology Data Exchange (ETDEWEB)

    De, Souvik [Artie McFerrin Department of Chemical Engineering, Texas A& M University, 77843-3122 TAMU College Station TX 77843-3122 USA; Nandasiri, Manjula I. [Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory, Richland WA 99352 USA; Schaef, Herbert T. [Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; McGrail, Benard Peter [Energy & Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Nune, Satish K. [Energy & Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Lutkenhaus, Jodie L. [Artie McFerrin Department of Chemical Engineering, Texas A& M University, 77843-3122 TAMU College Station TX 77843-3122 USA; Department of Materials Science & Engineering, Texas A& M University, 3122 TAMU College Station TX 77843-3122 USA

    2016-12-27

    Metal organic frameworks (MOFs) have gained tremendous attention for their porosity, size selectivity, and structural diversity. There is a need for MOF-based coatings, particularly in applications such as separations, electronics and energy; yet forming thin, functional, conformal coatings is prohibitive because MOFs exist as a powder. Layer-by- layer assembly, a versatile thin film coating approach, offers a unique solution to this problem, but this approach requires MOFs that are water-dispersible and bear a surface charge. Here, we address these issues by examining water-based dispersions of MIL-101(Cr) that facilitate the formation of robust polymer-MOF hybrid coatings. Specifically, the substrate to be coated is alternately exposed to an aqueous solution of poly(styrene sulfonate) and dispersion MIL-101(Cr), yielding linear film growth and coatings with a MOF content as high as 77 wt%.This approach is surface-agnostic, in which the coating is successfully applied to silicon, glass, flexible plastic, and even cotton fabric, conformally coating individual fibers. In contrast, prior attempts at forming MOF-coatings were severely limited to a handful of surfaces, required harsh chemical treatment, and were not conformal. The approach presented here unambiguously confirms that MOFs can be conformally coated onto complex and unusual surfaces, opening the door for a wide variety of applications.

  18. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-02-07

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  19. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-08-22

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  20. Metal-organic and zeolite imidazolate frameworks (MOFs and ZIFs) for highly selective separations

    Energy Technology Data Exchange (ETDEWEB)

    Yaghi, Omar M

    2012-09-17

    Metal-organic and zeolite imidazolate frameworks (MOFs and ZIFs) have been investigated for the realization as separation media with high selectivity. These structures are held together with strong bonds, making them architecturally, chemically, and thermally stable. Therefore, employing well designed building units, it is possible to discover promising materials for gas and vapor separation. This grant was focused on the study of MOFs and ZIFs with these specific objectives: (i) to develop a strategy for producing MOFs and ZIFs that combine high surface areas with active sites for their use in gas adsorption and separation of small organic compounds, (ii) to introduce active sites in the framework by a post-synthetic modification and metalation of MOFs and ZIFs, and (iii) to design and synthesize MOFs with extremely high surface areas and large pore volumes to accommodate large amounts of guest molecules. By the systematic study, this effort demonstrated how to introduce active functional groups in the frameworks, and this is also the origin of a new strategy, which is termed isoreticular functionalization and metalation. However, a large pore volume is still a prerequisite feature. One of the solutions to overcome this challenge is an isoreticular expansion of a MOF's structure. With triangular organic linker and square building units, we demonstrated that MOF-399 has a unit cell volume 17 times larger than that of the first reported material isoreticular to it, and it has the highest porosity (94%) and lowest density (0.126 g cm-3) of any MOF reported to date. MOFs are not just low density materials; the guest-free form of MOF-210 demonstrates an ultrahigh porosity, whose BET surface area was estimated to be 6240 m2 g-1 by N2 adsorption measurements.

  1. Design and Synthesis of Novel Porous Metal-Organic Frameworks (MOFs) Toward High Hydrogen Storage Capacity

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Eddaoudi [USF; Zaworotko, Michael [USF; Space, Brian [USF; Eckert, Juergen [USF

    2013-05-08

    Statement of Objectives: 1. Synthesize viable porous MOFs for high H2 storage at ambient conditions to be assessed by measuring H2 uptake. 2. Develop a better understanding of the operative interactions of the sorbed H2 with the organic and inorganic constituents of the sorbent MOF by means of inelastic neutron scattering (INS, to characterize the H2-MOF interactions) and computational studies (to interpret the data and predict novel materials suitable for high H2 uptake at moderate temperatures and relatively low pressures). 3. Synergistically combine the outcomes of objectives 1 and 2 to construct a made-to-order inexpensive MOF that is suitable for super H2 storage and meets the DOE targets - 6% H2 per weight (2kWh/kg) by 2010 and 9% H2 per weight (3kWh/kg) by 2015. The ongoing research is a collaborative experimental and computational effort focused on assessing H2 storage and interactions with pre-selected metal-organic frameworks (MOFs) and zeolite-like MOFs (ZMOFs), with the eventual goal of synthesizing made-to-order high H2 storage materials to achieve the DOE targets for mobile applications. We proposed in this funded research to increase the amount of H2 uptake, as well as tune the interactions (i.e. isosteric heats of adsorption), by targeting readily tunable MOFs:

  2. Visible Light Induced Organic Transformations Using Metal-Organic-Frameworks (MOFs).

    Science.gov (United States)

    Deng, Xiaoyu; Li, Zhaohui; García, Hermenegildo

    2017-08-22

    With the aim of developing renewable energy based processes, researchers are paying increasing interest to light induced organic transformations. Metal-organic frameworks (MOFs), a class of micro-/mesoporous hybrid materials, are recently emerging as a new type of photoactive materials for organic syntheses due to their unique structural characteristics. In this Review, we summarized the recent applications of MOFs as photocatalysts for light induced organic transformations, including (1) oxidation of alcohols, amines, alkene, alkanes and sulfides; (2) hydroxylation of aromatic compounds like benzene; (3) activation of the C-H bonds to construct new C-C or C-X bonds; (4) atom-transfer radical polymerization (ATRP). This Review starts with general background information of using MOFs in photocatalysis, followed by a description of light induced organic transformations promoted by photoactive inorganic nodes and photocatalytic active ligands in MOFs, respectively. Thereafter, the use of MOFs as multifunctional catalysts for light induced organic transformations via an efficient merge of the metal/ligand/guest based catalysis where the photocatalytic activity of MOFs plays a key role are discussed. Finally, the limitations, challenges and the future perspective of the application of MOFs for light induced organic transformations were addressed. The objective of this Review is to serve as a starting point for other researchers to get into this largely unexplored field. It is also our goal to stimulate intensive research in this field for rational designing of MOF materials to overcome their current limitations in photocatalysis, which can lead to more creative visible-light-induced organic transformations. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Adsorptive removal of hazardous materials using metal-organic frameworks (MOFs): a review.

    Science.gov (United States)

    Khan, Nazmul Abedin; Hasan, Zubair; Jhung, Sung Hwa

    2013-01-15

    Efficient removal of hazardous materials from the environment has become an important issue from a biological and environmental standpoint. Adsorptive removal of toxic components from fuel, waste-water or air is one of the most attractive approaches for cleaning technologies. Recently, porous metal-organic framework (MOF) materials have been very promising in the adsorption/separation of various liquids and gases due to their unique characteristics. This review summarizes the recent literatures on the adsorptive removal of various hazardous compounds mainly from fuel, water, and air by virgin or modified MOF materials. Possible interactions between the adsorbates and active adsorption sites of the MOFs will be also discussed to understand the adsorption mechanism. Most of the observed results can be explained with the following mechanisms: (1) adsorption onto a coordinatively unsaturated site, (2) adsorption via acid-base interaction, (3) adsorption via π-complex formation, (4) adsorption via hydrogen bonding, (5) adsorption via electrostatic interaction, and (6) adsorption based on the breathing properties of some MOFs and so on. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Metal-Organic Frameworks: Building Block Design Strategies for the Synthesis of MOFs.

    KAUST Repository

    Luebke, Ryan

    2014-09-01

    A significant and ongoing challenge in materials chemistry and furthermore solid state chemistry is to design materials with the desired properties and characteristics. The field of Metal-Organic Frameworks (MOFs) offers several strategies to address this challenge and has proven fruitful at allowing some degree of control over the resultant materials synthesized. Several methodologies for synthesis of MOFs have been developed which rely on use of predetermined building blocks. The work presented herein is focused on the utilization of two of these design principles, namely the use of molecular building blocks (MBBs) and supermolecular building blocks (SBBs) to target MOF materials having desired connectivities (topologies). These design strategies also permit the introduction of specific chemical moieties, allowing for modification of the MOFs properties. This research is predominantly focused on two platforms (rht-MOFs and ftw-MOFs) which topologically speaking are edge transitive binodal nets; ftw being a (4,12)-connected net and rht being a (3,24)-connected net. These highly connected nets (at least one node having connectivity greater than eight) have been purposefully targeted to increase the predictability of structural outcome. A general trend in topology is that there is an inverse relationship between the connectivity of the node(s) and the number of topological outcomes. Therefore the key to this research (and to effective use of the SBB and MBB approaches) is identification of conditions which allow for reliable formation of the targeted MBBs and SBBs. In the case of the research presented herein: a 12-connected Group IV or Rare Earth based hexanuclear MBB and a 24-connected transition metal based SBB were successfully targeted and synthesized. These two synthetic platforms will be presented and used as examples of how these design methods have been (and can be further) utilized to modify existing materials or develop new materials for gas storage and

  5. Theoretical model estimation of guest diffusion in Metal-Organic Frameworks (MOFs)

    KAUST Repository

    Zheng, Bin

    2015-08-11

    Characterizing molecule diffusion in nanoporous matrices is critical to understanding the novel chemical and physical properties of metal-organic frameworks (MOFs). In this paper, we developed a theoretical model to fastly and accurately compute the diffusion rate of guest molecules in a zeolitic imidazolate framework-8 (ZIF-8). The ideal gas or equilibrium solution diffusion model was modified to contain the effect of periodical media via introducing the possibility of guests passing through the framework gate. The only input in our model is the energy barrier of guests passing through the MOF’s gate. Molecular dynamics (MD) methods were employed to gather the guest density profile, which then was used to deduce the energy barrier values. This produced reliable results that require a simulation time of 5 picoseconds, which is much shorter when using pure MD methods (in the billisecond scale) . Also, we used density functional theory (DFT) methods to obtain the energy profile of guests passing through gates, as this does not require specification of a force field for the MOF degrees of freedom. In the DFT calculation, we only considered one gate of MOFs each time; as this greatly reduced the computational cost. Based on the obtained energy barrier values we computed the diffusion rate of alkane and alcohol in ZIF-8 using our model, which was in good agreement with experimental test results and the calculation values from standard MD model. Our model shows the advantage of obtaining accurate diffusion rates for guests in MOFs for a lower computational cost and shorter calculation time. Thus, our analytic model calculation is especially attractive for high-throughput computational screening of the dynamic performance of guests in a framework.

  6. Morphology and adsorption of chromium ion on uranium 1,2,4,5-benzenetetracarboxylic acid metal organic framework (MOF

    Directory of Open Access Journals (Sweden)

    Vala Remy M.K.

    2016-01-01

    Full Text Available In this paper, we report the synthesis of metal organic framework of uranium 1,2,4,5-benzene tetracarboxylic acid (U-H4btec MOF by solvothermal method. The obtained MOF was characterized by Fourier transform infrared spectroscopy (FTIR, Scanning electron microscopy (SEM, Transmission electron microscopy (TEM, X-ray diffraction spectroscopy (XRD, Energy dispersive spectroscopy (EDS, thermogravimetric and differential thermogravimetric analysis (TGA/DTA. The morphology of the uranium 1,2,4,5-benzene tetracarboxylic acid MOF observed by SEM, revealed the presence of flaky porous structure. Adsorption of Cr3+ from aqueous solution onto the uranium 1,2,4,5-benzene tetracarboxylic acid MOF was systematically studied. Langmuir and Freundlich adsorption isotherms were applied to determine the adsorption capacity of the MOF to form a monolayer. Kinetic determination of the adsorption of Cr3+ suggested both chemisorption and physisorption probably due to the presence of carbonyl groups within the MOF and its porous structure.

  7. A more efficient way to shape metal-organic framework (MOF) powder materials for hydrogen storage applications

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2015-04-01

    Full Text Available of Hydrogen Energy Vol. 40(13) A more efficient way to shape metal-organic framework (MOF) powder materials for hydrogen storage applications Jianwei Ren*, Nicholas M. Musyoka, Henrietta W. Langmi, Ashton Swartbooi, Brian C. North, Mkhulu Mathe Hy...

  8. Peptide Assembly-Driven Metal-Organic Framework (MOF) Motors for Micro Electric Generator

    Science.gov (United States)

    Ikezoe, Yasuhiro; Fang, Justin; Wasik, Tomasz L.; Uemura, Takashi; Zheng, Yongtai; Kitagawa, Susumu

    2014-01-01

    Peptide-MOF motors, whose motions are driven by anisotropic surface gradients created via peptide self-assembly around nanopores of MOFs, can rotate microscopic rotors and magnet fast enough to generate electric power of 0.1 µW. To make the peptide-MOF generator recyclable, a new MOF is applied as a host motor engine, which has a more rigid framework with higher H2O affinity so that peptide release occurs more efficiently via guest exchange without the destruction of MOF. PMID:25418936

  9. Synthesis and Electrospraying of Nanoscale MOF (Metal Organic Framework) for High-Performance CO2 Adsorption Membrane

    Science.gov (United States)

    Wahiduzzaman; Allmond, Kelsey; Stone, John; Harp, Spencer; Mujibur, Khan

    2017-01-01

    We report the sonochemical synthesis of MOF (metal organic framework) nanoparticles of 30-200 nm in size and electrospraying of those particles on electrospun nanofibers to process a MOF-attached nanofibrous membrane. This membrane displayed significant selectivity towards CO2 and capacity of adsorbing with 4000-5000 ppm difference from a mixed gas flow of 1% CO2 and 99% N2. Applying ultrasonic waves during the MOF synthesis offered rapid dispersion and formation of crystalline MOF nanoparticles in room temperature. The MOF nanoparticles of 100-200 nm in size displayed higher surface area and adsorption capacity comparing to that of 30-60 nm in size. Nanofibrous membrane was produced by electrospinning of MOF blended PAN solution followed by electrospraying of additional MOF nanoparticles. This yielded uniform MOF deposition on nanofibers, occurred due to electrostatic attraction between highly charged nanoparticles and conductive nanofibers. A test bench for real-time CO2 adsorption at room temperature was built with non-dispersive Infrared (NDIR) CO2 sensors. Comparative tests were performed on the membrane to investigate its enhanced adsorption capacity. Three layers of the as-produced membranes displayed CO2 adsorption for approximately 2 h. Thermogravimetric analysis (TGA) of the membrane showed the thermal stability of the MOF and PAN up to 290 and 425 °C, respectively.

  10. Hydrogen sensing properties of nanocomposite graphene oxide/Co-based metal organic frameworks (Co-MOFs@GO)

    Science.gov (United States)

    Fardindoost, Somayeh; Hatamie, Shadie; Iraji Zad, Azam; Razi Astaraei, Fatemeh

    2018-01-01

    This paper reports on hydrogen sensing based graphene oxide hybrid with Co-based metal organic frameworks (Co-MOFs@GO) prepared by the hydrothermal process. The texture and morphology of the hybrid were characterized by powder x-ray diffraction, scanning electron microscopy and Brunauer–Emmett–Teller analysis. Porous flower like structures assembled from Co-MOFs and GO flakes with sufficient specific surface area are obtained, which are ideal for gas molecules diffusion and interactions. Sensing performance of Co-MOFs@GO were tested and also improved by sputtering platinum (Pt) as a catalyst. The Pt-sputtered Co-MOFs@GO show outstanding hydrogen resistive-sensing with response and recovery times below 12 s at 15 °C. Also, they show stable, repeatable and selective responses to the target gas which make it suitable for the development of a high performance hydrogen sensor.

  11. Metal Organic Framework

    Indian Academy of Sciences (India)

    IAS Admin

    X-ray crystallography is the most comprehensive character- ization tool to gain a molecular level understanding of a range of crystalline materials. One of the recent areas in which research with the aid of crystallography has exploded, is the metal organic frameworks (MOFs). These are porous crystal- line solids with ...

  12. Removal of hazardous organics from water using metal-organic frameworks (MOFs): plausible mechanisms for selective adsorptions.

    Science.gov (United States)

    Hasan, Zubair; Jhung, Sung Hwa

    2015-01-01

    Provision of clean water is one of the most important issues worldwide because of continuing economic development and the steady increase in the global population. However, clean water resources are decreasing everyday, because of contamination with various pollutants including organic chemicals. Pharmaceutical and personal care products, herbicides/pesticides, dyes, phenolics, and aromatics (from sources such as spilled oil) are typical organics that should be removed from water. Because of their huge porosities, designable pore structures, and facile modification, metal-organic frameworks (MOFs) are used in various adsorption, separation, storage, and delivery applications. In this review, the adsorptive purifications of contaminated water with MOFs are discussed, in order to understand possible applications of MOFs in clean water provision. More importantly, plausible adsorption or interaction mechanisms and selective adsorptions are summarized. The mechanisms of interactions such as electrostatic interaction, acid-base interaction, hydrogen bonding, π-π stacking/interaction, and hydrophobic interaction are discussed for the selective adsorption of organics over MOFs. The adsorption mechanisms will be very helpful not only for understanding adsorptions but also for applications of adsorptions in selective removal, storage, delivery and so on. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Crystal growth mechanisms and morphological control of the prototypical metal-organic framework MOF-5 revealed by atomic force microscopy.

    Science.gov (United States)

    Cubillas, Pablo; Anderson, Michael W; Attfield, Martin P

    2012-11-26

    Crystal growth of the metal-organic framework MOF-5 was studied by atomic force microscopy (AFM) for the first time. Growth under low supersaturation conditions was found to occur by a two-dimensional or spiral crystal growth mechanism. Observation of developing nuclei during the former reveals growth occurs through a process of nucleation and spreading of metastable and stable sub-layers revealing that MOFs may be considered as dense phase structures in terms of crystal growth, even though they contain sub-layers consisting of ordered framework and disordered non-framework components. These results also support the notion this may be a general mechanism of surface crystal growth at low supersaturation applicable to crystalline nanoporous materials. The crystal growth mechanism at the atomistic level was also seen to vary as a function of the growth solution Zn/H(2)bdc ratio producing square terraces with steps parallel to the direction or rhombus-shaped terraces with steps parallel to the direction when the Zn/H(2)bdc ratio was >1 or about 1, respectively. The change in relative growth rates can be explained in terms of changes in the solution species concentrations and their influence on growth at different terrace growth sites. These results were successfully applied to the growth of as-synthesized cube-shaped crystals to increase expression of the {111} faces and to grow octahedral crystals of suitable quality to image using AFM. This modulator-free route to control the crystal morphology of MOF-5 crystals should be applicable to a wide variety of MOFs to achieve the desired morphological control for performance enhancement in applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Processing and Performance of MOF (Metal Organic Framework)-Loaded PAN Nanofibrous Membrane for CO2 Adsorption

    Science.gov (United States)

    Wahiduzzaman; Khan, Mujibur R.; Harp, Spencer; Neumann, Jeffrey; Sultana, Quazi Nahida

    2016-04-01

    The objective of this experimental study is to produce a nanofibrous membrane functionalized with adsorbent particles called metal organic framework (MOF) in order to adsorb CO2 from a gas source. Therefore, Polyacrylonitrile (PAN) was chosen as the precursor for nanofibers and HKUST-1, a Cu-based MOF, was chosen as adsorbent. The experimental process consists of electrospinning PAN solution blended with HKUST-1 to produce a nanofibrous mat as working substrates. The fibers were collected in a cylindrical canister model. SEM image of this mat showed nanofibers with the presence of small adsorbent particles, impregnated into the as-spun fibers discretely. To increase the amount of MOF particles for effectual gas adsorption, a secondary solvothermal process of producing MOF particles on the fibers was required. This process consists of multiple growth cycles of HKUST-1 particles by using a sol-gel precursor. SEM images showed uniform distribution of porous MOF particles of 2-4 µm in size on the fiber surface. Energy dispersive spectroscopy report of the fiber confirmed the presence of MOF particles through the identification of characteristic Copper elemental peaks of HKUST-1. To determine the thermal stability of the fibrous membrane, Thermogravimetric analysis of HKUST-1 consisting of PAN fiber was performed where a total weight loss of 40% between 210 and 360 °C was observed, hence proving the high-temperature durability of the synthesized membrane. BET surface area of the fiber membrane was measured as 540.73 m2/g. The fiber membrane was then placed into an experimental test bench containing a mixed gas inflow of CO2 and N2. Using non-dispersive infrared CO2 sensors connected to the inlet and outlet port of the bench, significant reduction of CO2 in concentration was measured. Comparative IR spectroscopic analysis between the gas-treated and gas untreated fiber samples showed the presence of characteristic peak in the vicinity of 2300 and 2400 cm-1 which

  15. Review on processing of metal-organic framework (MOF) materials towards system integration for hydrogen storage

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2014-09-01

    Full Text Available materials to form part of a practical hydrogen storage system, knowledge of the ‘processing’ techniques to improve the properties of the powders is essential. However, the processing routes of MOF materials towards system integration are rarely reviewed...

  16. Metal organic frameworks for gas storage

    KAUST Repository

    Alezi, Dalal

    2016-06-09

    Embodiments provide a method of storing a compound using a metal organic framework (MOF). The method includes contacting one or more MOFs with a fluid and sorbing one or more compounds, such as O2 and CH4. O2 and CH4 can be sorbed simultaneously or in series. The metal organic framework can be an M-soc-MOF, wherein M can include aluminum, iron, gallium, indium, vanadium, chromium, titanium, or scandium.

  17. Stable Aluminum Metal-Organic Frameworks (Al-MOFs) for Balanced CO2 and Water Selectivity.

    Science.gov (United States)

    Li, Haiwei; Feng, Xiao; Ma, Dou; Zhang, Mengxi; Zhang, Yuanyuan; Liu, Yi; Zhang, Jinwei; Wang, Bo

    2018-01-31

    Three new Al-MOFs in the formation of [Al 4 (OH) 2 (OCH 3 ) 4 (OH-BDC) 3 ]·xH 2 O (BIT-72), [Al 4 (OH) 2 (OCH 3 ) 4 (CH 3 -BDC) 3 ]·xH 2 O (BIT-73) and {Al 4 (OH) 2 (OCH 3 ) 4 [(CH 3 ) 2 -BDC] 3 }·xH 2 O (BIT-74) have been synthesized by assembling Al 3+ ion with terephthalic acid ions decorated with monohydroxyl, monomethyl or dimethyl groups, respectively. All of these three MOFs exhibit high stability in boiling water and acidic conditions. Among them, BIT-72 shows the highest surface area of 1618 m 2 ·g -1 and IAST CO 2 /N 2 selectivity of 48, while BIT-73 and BIT-74 present moderate IAST CO 2 /N 2 selectivity and much lower H 2 O capacity below P/P 0 = 0.3. The high CO 2 /N 2 selectivity together with alleviative H 2 O sorption at low water relative pressure may provide promising potential in postcombustion CO 2 capture.

  18. Novel Applications for Oxalate-Phosphate-Amine Metal-Organic-Frameworks (OPA-MOFs): Can an Iron-Based OPA-MOF Be Used as Slow-Release Fertilizer?

    Science.gov (United States)

    Anstoetz, Manuela; Rose, Terry J; Clark, Malcolm W; Yee, Lachlan H; Raymond, Carolyn A; Vancov, Tony

    2015-01-01

    A porous iron-based oxalate-phosphate-amine metal-organic framework material (OPA-MOF) was investigated as a microbially-induced slow-release nitrogen (N) and phosphorus (P) fertilizer. Seedling growth, grain yields, nutrient uptake of wheat plants, and soil dynamics in incubated soil, were investigated using OPA-MOF vs standard P (triple-superphosphate) and N (urea) fertilizers in an acidic Ferralsol at two application rates (equivalent 120 and 40 kg N ha(-1)). While urea hydrolysis in the OPA-MOF treatment was rapid, conversion of ammonium to nitrate was significantly inhibited compared to urea treatment. Reduced wheat growth in OPA-MOF treatments was not caused by N-deficiency, but by limited P-bioavailability. Two likely reasons were slow P-mobilisation from the OPA-MOF or rapid P-binding in the acid soil. P-uptake and yield in OPA-MOF treatments were significantly higher than in nil-P controls, but significantly lower than in conventionally-fertilised plants. OPA-MOF showed potential as enhanced efficiency N fertilizer. However, as P-bioavailability was insufficient to meet plant demands, further work should determine if P-availability may be enhanced in alkaline soils, or whether central ions other than Fe, forming the inorganic metal-P framework in the MOF, may act as a more effective P-source in acid soils.

  19. Novel Applications for Oxalate-Phosphate-Amine Metal-Organic-Frameworks (OPA-MOFs: Can an Iron-Based OPA-MOF Be Used as Slow-Release Fertilizer?

    Directory of Open Access Journals (Sweden)

    Manuela Anstoetz

    Full Text Available A porous iron-based oxalate-phosphate-amine metal-organic framework material (OPA-MOF was investigated as a microbially-induced slow-release nitrogen (N and phosphorus (P fertilizer. Seedling growth, grain yields, nutrient uptake of wheat plants, and soil dynamics in incubated soil, were investigated using OPA-MOF vs standard P (triple-superphosphate and N (urea fertilizers in an acidic Ferralsol at two application rates (equivalent 120 and 40 kg N ha(-1. While urea hydrolysis in the OPA-MOF treatment was rapid, conversion of ammonium to nitrate was significantly inhibited compared to urea treatment. Reduced wheat growth in OPA-MOF treatments was not caused by N-deficiency, but by limited P-bioavailability. Two likely reasons were slow P-mobilisation from the OPA-MOF or rapid P-binding in the acid soil. P-uptake and yield in OPA-MOF treatments were significantly higher than in nil-P controls, but significantly lower than in conventionally-fertilised plants. OPA-MOF showed potential as enhanced efficiency N fertilizer. However, as P-bioavailability was insufficient to meet plant demands, further work should determine if P-availability may be enhanced in alkaline soils, or whether central ions other than Fe, forming the inorganic metal-P framework in the MOF, may act as a more effective P-source in acid soils.

  20. Submicron sized water-stable metal organic framework (bio-MOF-11) for catalytic degradation of pharmaceuticals and personal care products.

    Science.gov (United States)

    Azhar, Muhammad Rizwan; Vijay, Periasamy; Tadé, Moses O; Sun, Hongqi; Wang, Shaobin

    2018-04-01

    Water-stable and active metal organic frameworks (MOFs) are important materials for mitigation of water contaminants via adsorption and catalytic reactions. In this study, a highly water-stable Co-based MOF, namely bio-MOF-11-Co, was synthesized by a simplified benign method. Moreover, it was used as a catalyst in successful activation of peroxymonsulfate for catalytic degradation of sulfachloropyradazine (SCP) and para-hydroxybenzoic acid (p-HBA) as representatives of pharmaceuticals and personal care products, respectively. The bio-MOF-11-Co showed rapid degradation of both p-HBA and SCP and could be reused multiple times without losing the activity by simply water washing. The effects of catalyst and PMS loadings as well as temperature were further studied, showing that high catalyst and PMS loadings as well as temperature produced faster kinetic degradation of p-HBA and SCP. The generation of highly reactive and HO radicals during the degradation was investigated by quenching tests and electron paramagnetic resonance. A plausible degradation mechanism was proposed based on the functionalities in the bio-MOF-11-Co. The availability of electron rich nucleobase adenine reinforced the reaction kinetics by electron donation along with cobalt atoms in the bio-MOF-11-Co structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Minerals with metal-organic framework structures.

    Science.gov (United States)

    Huskić, Igor; Pekov, Igor V; Krivovichev, Sergey V; Friščić, Tomislav

    2016-08-01

    Metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. We now demonstrate an unexpected link between mineralogy and MOF chemistry by discovering that the rare organic minerals stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials and represent, so far, unique examples of open framework architectures in organic minerals.

  2. Metal-organic frameworks in chromatography.

    Science.gov (United States)

    Yusuf, Kareem; Aqel, Ahmad; ALOthman, Zeid

    2014-06-27

    Metal-organic frameworks (MOFs) emerged approximately two decades ago and are the youngest class of porous materials. Despite their short existence, MOFs are finding applications in a variety of fields because of their outstanding chemical and physical properties. This review article focuses on the applications of MOFs in chromatography, including high-performance liquid chromatography (HPLC), gas chromatography (GC), and other chromatographic techniques. The use of MOFs in chromatography has already had a significant impact; however, the utilisation of MOFs in chromatography is still less common than other applications, and the number of MOF materials explored in chromatography applications is limited. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Metal-organic framework materials with ultrahigh surface areas

    Science.gov (United States)

    Farha, Omar K.; Hupp, Joseph T.; Wilmer, Christopher E.; Eryazici, Ibrahim; Snurr, Randall Q.; Gomez-Gualdron, Diego A.; Borah, Bhaskarjyoti

    2015-12-22

    A metal organic framework (MOF) material including a Brunauer-Emmett-Teller (BET) surface area greater than 7,010 m.sup.2/g. Also a metal organic framework (MOF) material including hexa-carboxylated linkers including alkyne bond. Also a metal organic framework (MOF) material including three types of cuboctahedron cages fused to provide continuous channels. Also a method of making a metal organic framework (MOF) material including saponifying hexaester precursors having alkyne bonds to form a plurality of hexa-carboxylated linkers including alkyne bonds and performing a solvothermal reaction with the plurality of hexa-carboxylated linkers and one or more metal containing compounds to form the MOF material.

  4. Synthesis and characterization of magnetic metal-organic framework (MOF) as a novel sorbent, and its optimization by experimental design methodology for determination of palladium in environmental samples.

    Science.gov (United States)

    Bagheri, Akbar; Taghizadeh, Mohsen; Behbahani, Mohammad; Asgharinezhad, Ali Akbar; Salarian, Mani; Dehghani, Ali; Ebrahimzadeh, Homeira; Amini, Mostafa M

    2012-09-15

    This paper describes the synthesis and application of novel magnetic metal-organic framework (MOF) [(Fe(3)O(4)-Pyridine)/Cu(3)(BTC)(2)] for preconcentration of Pd(II) and its determination by flame atomic absorption spectrometry (FAAS). A Box-Behnken design was used to find the optimum conditions for the preconcentration procedure through response surface methodology. Three variables including amount of magnetic MOF, extraction time, and pH of extraction were selected as factors for adsorption step, and in desorption step, four parameters including type, volume, and concentration of eluent, and desorption time were selected in the optimization study. These values were 30 mg, 6 min, 6.9, K(2)SO(4)+NaOH, 6 mL, 9.5 (w/v %)+0.01 mol L(-1), 15.5 min, for amount of MOF, extraction time, pH of extraction, type, volume, and concentration of the eluent, and desorption time, respectively. The preconcentration factor (PF), relative standard deviation (RSD), limit of detection (LOD), and adsorption capacity of the method were found to be 208, 2.1%, 0.37 ng mL(-1), and 105.1 mg g(-1), respectively. It was found that the magnetic MOF has more capacity compared to Fe(3)O(4)-Py. Finally, the magnetic MOF was successfully applied for rapid extraction of trace amounts of Pd (II) ions in fish, sediment, soil, and water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Interplay of metalloligand and organic ligand to tune micropores within isostructural mixed-metal organic frameworks (M'MOFs) for their highly selective separation of chiral and achiral small molecules

    NARCIS (Netherlands)

    Das, M. C.; Guo, Q.; He, Y.; Kim, J.; Zhao, C.-G.; Hong, K.; Xiang, S.; Zhang, Z.; Thomas, K. M.; Krishna, R.; Chen, B.

    2012-01-01

    Four porous isostructural mixed-metal-organic frameworks (M′MOFs) have been synthesized and structurally characterized. The pores within these M′MOFs are systematically tuned by the interplay of both the metalloligands and organic ligands which have enabled us not only to direct their highly

  6. Unusual Transformation from a Solvent-Stabilized 1D Coordination Polymer to a Metal-Organic Framework (MOF)-Like Cross-Linked 3D Coordination Polymer.

    Science.gov (United States)

    Lee, Seung-Chul; Choi, Eun-Young; Lee, Sang-Beom; Kim, Sang-Wook; Kwon, O-Pil

    2015-10-26

    An unusual 1D-to-3D transformation of a coordination polymer based on organic linkers containing highly polar push-pull π-conjugated side chains is reported. The coordination polymers are synthesized from zinc nitrate and an organic linker, namely, 2,5-bis{4-[1-(4-nitrophenyl)pyrrolidin-2-yl]butoxy}terephthalic acid, which possesses highly polar (4-nitrophenyl)pyrrolidine groups, with high dipole moments of about 7 D. The coordination polymers exhibit an unusual transformation from a soluble, solvent-stabilized 1D coordination polymer into an insoluble, metal-organic framework (MOF)-like 3D coordination polymer. The coordination polymer exhibits good film-forming ability, and the MOF-like films are insoluble in conventional organic solvents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Loading of Two Related Metal-Organic Frameworks (MOFs, [Cu2(bdc2(dabco] and [Cu2(ndc2(dabco], with Ferrocene

    Directory of Open Access Journals (Sweden)

    Wolfgang Wenzel

    2011-09-01

    Full Text Available We have studied the loading of two related, similar porous metal-organic frameworks (MOFs [Cu2(bdc2(dabco] (1, and [Cu2(ndc2(dabco] (2 with ferrocene by exposing bulk powder samples to the corresponding vapor. On the basis of powder X-ray diffraction data and molecular dynamics (MD calculations we propose that each pore can store one ferrocene molecule. Despite the rather pronounced similarity of the two MOFs a quite different behavior is observed, for 1 loading with ferrocene leads to an anisotropic 1% contraction, whereas for 2 no deformation is observed. Mössbauer spectroscopy studies reveal that the Fe oxidation level remains unchanged during the process. Time dependent studies reveal that the diffusion constant governing the loading from the gas-phase for 1 is approximately three times larger than the value for 2.

  8. Understanding Hydrogen Sorption in In- soc -MOF: A Charged Metal-Organic Framework with Open-Metal Sites, Narrow Channels, and Counterions

    KAUST Repository

    Pham, Tony

    2015-03-04

    © 2015 American Chemical Society. Grand canonical Monte Carlo (GCMC) simulations of hydrogen sorption were performed in In-soc-MOF, a charged metal-organic framework (MOF) that contains In3O trimers coordinated to 5,5′-azobis(1,3-benzenedicarboxylate) linkers. The MOF contains nitrate counterions that are located in carcerand-like capsules of the framework. This MOF was shown to have a high hydrogen uptake at 77 K and 1.0 atm. The simulations were performed with a potential that includes explicit many-body polarization interactions, which were important for modeling gas sorption in a charged/polar MOF such as In-soc-MOF. The simulated hydrogen sorption isotherms were in good agreement with experiment in this challenging platform for modeling. The simulations predict a high initial isosteric heat of adsorption, Qst, value of about 8.5 kJ mol-1, which is in contrast to the experimental value of 6.5 kJ mol-1 for all loadings. The difference in the Qst behavior between experiment and simulation is attributed to the fact that, in experimental measurements, the sorbate molecules cannot access the isolated cages containing the nitrate ions, the most energetically favorable site in the MOF, at low pressures due to an observed diffusion barrier. In contrast, the simulations were able to capture the sorption of hydrogen onto the nitrate ions at low loading due to the equilibrium nature of GCMC simulations. The experimental Qst values were reproduced in simulation by blocking access to all of the nitrate ions in the MOF. Furthermore, at 77 K, the sorbed hydrogen molecules were reminiscent of a dense fluid in In-soc-MOF starting at approximately 5.0 atm, and this was verified by monitoring the isothermal compressibility, βT, values. The favorable sites for hydrogen sorption were identified from the polarization distribution as the nitrate ions, the In3O trimers, and the azobenzene nitrogen atoms. Lastly, the two-dimensional quantum rotational levels

  9. Reconfigurable electronics using conducting metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Talin, Albert Alec; Leonard, Francois; Stavila, Vitalie

    2017-07-18

    A device including a porous metal organic framework (MOF) disposed between two terminals, the device including a first state wherein the MOF is infiltrated by a guest species to form an electrical path between the terminals and a second state wherein the electrical conductivity of the MOF is less than the electrical conductivity in the first state. A method including switching a porous metal organic framework (MOF) between two terminals from a first state wherein a metal site in the MOF is infiltrated by a guest species that is capable of charge transfer to a second state wherein the MOF is less electrically conductive than in the first state.

  10. Thin-Film Nanocomposite (TFN) Membranes Incorporated with Super-Hydrophilic Metal-Organic Framework (MOF) UiO-66: Toward Enhancement of Water Flux and Salt Rejection.

    Science.gov (United States)

    Ma, Dangchen; Peh, Shing Bo; Han, Gang; Chen, Shing Bor

    2017-03-01

    Zirconiumv (IV)-carboxylate metal-organic framework (MOF) UiO-66 nanoparticles were successfully synthesized and incorporated in the polyamide (PA) selective layer to fabricate novel thin-film nanocomposite (TFN) membranes. Compared to unmodified pure polyamide thin-film composite (TFC) membranes, the incorporation of UiO-66 nanoparticles significantly changes the membrane morphology and chemistry, leading to an improvement of intrinsic separation properties due to the molecular sieving and superhydrophilic nature of UiO-66 particles. The best performing TFN-U2 (0.1 wt % particle loading) membrane not only shows a 52% increase of water permeability but also maintains salt rejection levels (∼95%) similar to the benchmark. The effects of UiO-66 loading on the forward osmosis (FO) performance were also investigated. Incorporation of 0.1 wt % UiO-66 produced a maximum water flux increase of 40% and 25% over the TFC control under PRO and FO modes, when 1 M NaCl was used as the draw solution against deionized water feed. Meanwhile, solute reverse flux was maintained at a relatively low level. In addition, TFN-U2 membrane displayed a relatively linear increase in FO water flux with increasing NaCl concentration up to 2.0 M, suggesting a slightly reduced internal concentration polarization effect. To our best knowledge, the current study is the first to consider implementation of Zr-MOFs (UiO-66) onto TFN-FO membranes.

  11. Direct calorimetric measurement of enthalpy of adsorption of carbon dioxide on CD-MOF-2, a green metal-organic framework.

    Science.gov (United States)

    Wu, Di; Gassensmith, Jeremiah J; Gouvêa, Douglas; Ushakov, Sergey; Stoddart, J Fraser; Navrotsky, Alexandra

    2013-05-08

    The enthalpy of adsorption of CO2 on an environmentally friendly metal-organic framework, CD-MOF-2, has been determined directly for the first time using adsorption calorimetry at 25 °C. This calorimetric methodology provides a much more accurate and model-independent measurement of adsorption enthalpy than that obtained by calculation from the adsorption isotherms, especially for systems showing complex and strongly exothermic adsorption behavior. The differential enthalpy of CO2 adsorption shows enthalpy values in line with chemisorption behavior. At near-zero coverage, an irreversible binding event with an enthalpy of -113.5 kJ/mol CO2 is observed, which is followed by a reversible -65.4 kJ/mol binding event. These enthalpies are assigned to adsorption on more and less reactive hydroxyl groups, respectively. Further, a second plateau shows an enthalpy of -40.1 kJ/mol and is indicative of physisorbed CO2. The calorimetric data confirm the presence of at least two energetically distinct binding sites for chemisorbed CO2 on CD-MOF-2.

  12. On demand: The singular rht net, an ideal blueprint for the construction of a metal-organic framework (mof) platform

    KAUST Repository

    Eubank, Jarrod F.

    2012-09-07

    The exceptional nature of the rht-MOF platform, based on a singular edge-transitive net (the only net for the combination of 3- and 24-connected nodes), makes it an ideal target in crystal chemistry. The high level of control indicates an unparalleled blueprint for isoreticular functional materials (without concern for interpenetration) for targeted applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Metal organic frameworks (MOFs) for magnetic solid-phase extraction of pyrazole/pyrrole pesticides in environmental water samples followed by HPLC-DAD determination.

    Science.gov (United States)

    Ma, Jiping; Yao, Zhidan; Hou, Liwei; Lu, Wenhui; Yang, Qipeng; Li, Jinhua; Chen, Lingxin

    2016-12-01

    Magnetic metal-organic frameworks (MOFs, [MIL-101]) were prepared and used as magnetic solid-phase extraction (MSPE) adsorbents for preconcentration of four kinds of pyrazole/pyrrole pesticides (flusilazole, fipronil, chlorfenapyr, and fenpyroximate) in environmental water samples, followed by high-performance liquid chromatography-diode-array detector (HPLC-DAD) determination. Several variables affecting MSPE efficiency were systematically investigated, including amount of MIL-101, extraction time, sample pH, salt concentration, type of desorption solvent and desorption number of times. Under optimized conditions, excellent linearity was achieved in the range of 5.0-200.0μg/L for flusilazole and fipronil, and 2.0-200.0μg/L for chlorfenapyr and fenpyroximate, with correlation coefficients r>0.9911. Limits of detection and quantification were 0.3-1.5μg/L and 1.0-5.0μg/L, respectively. The intra-day and inter-day precision (relative standard deviation, n=6, %) at three spiked levels were 1.1-5.4% and 3.9-7.8% in terms of peak area, respectively. The method recoveries at three fortified concentration levels ranged from 81.8% to 107.5% for reservoir water samples, 81.0-99.5% for river water samples, and 80.2-106.5% for seawater samples. The developed MOFs based MSPE coupled with HPLC method proved to be a convenient, rapid and eco-friendly alternative to the sensitive determination of pyrazole/pyrrole pesticides with high repeatability and excellent practical applicability. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Zhenzhong Guo

    2016-10-01

    Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.

  15. Novel Metal Organic Framework Synthesis for Spacecraft Oxygen Capture Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek and University of Utah propose to develop novel metal organic framework (MOF) material to efficiently capture oxygen in spacecraft cabin environment. The...

  16. Metal organic frameworks for removal of compounds from a fluid

    KAUST Repository

    Eddaoudi, Mohamed

    2016-03-03

    Embodiments provide a method of compound removal from a fluid. The method includes contacting one or more metal organic framework (MOF) compositions with a fluid and sorbing one or more compounds, such as CO2, H2S and condensable hydrocarbons. One or more of CO2, H2S and condensable hydrocarbons can be sorbed simultaneously or in series. The metal organic framework can be an M-soc-MOF.

  17. Mechanical Alloying of Metal-Organic Frameworks.

    Science.gov (United States)

    Panda, Tamas; Horike, Satoshi; Hagi, Keisuke; Ogiwara, Naoki; Kadota, Kentaro; Itakura, Tomoya; Tsujimoto, Masahiko; Kitagawa, Susumu

    2017-02-20

    The solvent-free mechanical milling process for two distinct metal-organic framework (MOF) crystals induced the formation of a solid solution, which is not feasible by conventional solution-based syntheses. X-ray and STEM-EDX studies revealed that performing mechanical milling under an Ar atmosphere promotes the high diffusivity of each metal ion in an amorphous solid matrix; the amorphous state turns into the porous crystalline structure by vapor exposure treatment to form a new phase of a MOF solid solution. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Photochemistry in a 3D metal-organic framework (MOF): monitoring intermediates and reactivity of the fac-to-mer photoisomerization of Re(diimine)(CO)3Cl incorporated in a MOF.

    Science.gov (United States)

    Easun, Timothy L; Jia, Junhua; Calladine, James A; Blackmore, Danielle L; Stapleton, Christopher S; Vuong, Khuong Q; Champness, Neil R; George, Michael W

    2014-03-03

    The mechanism and intermediates in the UV-light-initiated ligand rearrangement of fac-Re(diimine)(CO)3Cl to form the mer isomer, when incorporated into a 3D metal-organic framework (MOF), have been investigated. The structure hosting the rhenium diimine complex is a 3D network with the formula {Mn(DMF)2[LRe(CO)3Cl]}∞ (ReMn; DMF = N,N-dimethylformamide), where the diimine ligand L, 2,2'-bipyridine-5,5'-dicarboxylate, acts as a strut of the MOF. The incorporation of ReMn into a KBr disk allows spatial distribution of the mer-isomer photoproduct in the disk to be mapped and spectroscopically characterized by both Fourier transform infrared and Raman microscopy. Photoisomerization has been monitored by IR spectroscopy and proceeds via dissociation of a CO to form more than one dicarbonyl intermediate. The dicarbonyl species are stable in the solid state at 200 K. The photodissociated CO ligand appears to be trapped within the crystal lattice and, upon warming above 200 K, readily recombines with the dicarbonyl intermediates to form both the fac-Re(diimine)(CO)3Cl starting material and the mer-Re(diimine)(CO)3Cl photoproduct. Experiments over a range of temperatures (265-285 K) allow estimates of the activation enthalpy of recombination for each process of ca. 16 (±6) kJ mol(-1) (mer formation) and 23 (±4) kJ mol(-1) (fac formation) within the MOF. We have compared the photochemistry of the ReMn MOF with a related alkane-soluble Re(dnb)(CO)3Cl complex (dnb = 4,4'-dinonyl-2,2'-bipyridine). Time-resolved IR measurements clearly show that, in an alkane solution, the photoinduced dicarbonyl species again recombines with CO to both re-form the fac-isomer starting material and form the mer-isomer photoproduct. Density functional theory calculations of the possible dicarbonyl species aids the assignment of the experimental data in that the ν(CO) IR bands of the CO loss intermediate are, as expected, shifted to lower energy when the metal is bound to DMF rather than to an

  19. Metal organic frameworks for the catalytic detoxification of chemical warfare nerve agents

    Science.gov (United States)

    Hupp, Joseph T.; Farha, Omar K.; Katz, Michael J.; Mondloch, Joseph E.

    2017-04-18

    A method of using a metal organic framework (MOF) comprising a metal ion and an at least bidendate organic ligand to catalytically detoxify chemical warfare nerve agents including exposing the metal-organic-framework (MOF) to the chemical warfare nerve agent and catalytically decomposing the nerve agent with the MOF.

  20. Applications of metal-organic frameworks in heterogeneous supramolecular catalysis.

    Science.gov (United States)

    Liu, Jiewei; Chen, Lianfen; Cui, Hao; Zhang, Jianyong; Zhang, Li; Su, Cheng-Yong

    2014-08-21

    This review summarizes the use of metal-organic frameworks (MOFs) as a versatile supramolecular platform to develop heterogeneous catalysts for a variety of organic reactions, especially for liquid-phase reactions. Following a background introduction about catalytic relevance to various metal-organic materials, crystal engineering of MOFs, characterization and evaluation methods of MOF catalysis, we categorize catalytic MOFs based on the types of active sites, including coordinatively unsaturated metal sites (CUMs), metalloligands, functional organic sites (FOS), as well as metal nanoparticles (MNPs) embedded in the cavities. Throughout the review, we emphasize the incidental or deliberate formation of active sites, the stability, heterogeneity and shape/size selectivity for MOF catalysis. Finally, we briefly introduce their relevance into photo- and biomimetic catalysis, and compare MOFs with other typical porous solids such as zeolites and mesoporous silica with regard to their different attributes, and provide our view on future trends and developments in MOF-based catalysis.

  1. Metal-organic frameworks with high capacity and selectivity for harmful gases

    OpenAIRE

    Britt, David; Tranchemontagne, David; Yaghi, Omar M.

    2008-01-01

    Benchmarks have been established for the performance of six metal-organic frameworks (MOFs) and isoreticular MOFs (IRMOFs, which have the same underlying topology as MOF-5), MOF-5, IRMOF-3, MOF-74, MOF-177, MOF-199, and IRMOF-62, as selective adsorbents for eight harmful gases: sulfur dioxide, ammonia, chlorine, tetrahydrothiophene, benzene, dichloromethane, ethylene oxide, and carbon monoxide. Kinetic breakthrough measurements are used to determine the calculated dynamic adsorption capacity ...

  2. Interpenetration as a Mechanism for Negative Thermal Expansion in the Metal-Organic Framework Cu3(btb)2 (MOF-14)

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yue; Peterson, Vanessa K.; Luks, Emily; Darwish, Tamim A.; Kepert, Cameron J. [Sydney; (ANSTO)

    2014-07-11

    Metal–organic framework materials (MOFs) have recently been shown in some cases to exhibit strong negative thermal expansion (NTE) behavior, while framework interpenetration has been found to reduce NTE in many materials. Using powder and single-crystal diffraction methods we investigate the thermal expansion behavior of interpenetrated Cu3(btb)2 (MOF-14) and find that it exhibits an anomalously large NTE effect. Temperature-dependent structural analysis shows that, contrary to other interpenetrated materials, in MOF-14 the large positive thermal expansion of weak interactions that hold the interpenetrating networks together results in a low-energy contractive distortion of the overall framework structure, demonstrating a new mechanism for NTE.

  3. Reticular Chemistry at Its Best: Directed Assembly of Hexagonal Building Units into the Awaited Metal-Organic Framework with the Intricate Polybenzene Topology, pbz-MOF

    KAUST Repository

    Alezi, Dalal

    2016-10-05

    The ability to direct the assembly of hexagonal building units offers great prospective to construct the awaited and looked-for hypothetical polybenzene (pbz) or “cubic graphite” structure, described 70 years ago. Here, we demonstrate the successful use of reticular chemistry as an appropriate strategy for the design and deliberate construction of a zirconium-based metal–organic framework (MOF) with the intricate pbz underlying net topology. The judicious selection of the perquisite hexagonal building units, six connected organic and inorganic building blocks, allowed the formation of the pbz-MOF-1, the first example of a Zr(IV)-based MOF with pbz topology. Prominently, pbz-MOF-1 is highly porous, with associated pore size and pore volume of 13 Å and 0.99 cm3 g–1, respectively, and offers high gravimetric and volumetric methane storage capacities (0.23 g g–1 and 210.4 cm3 (STP) cm–3 at 80 bar). Notably, the pbz-MOF-1 pore system permits the attainment of one of the highest CH4 adsorbed phase density enhancements at high pressures (0.15 and 0.21 g cm–3 at 35 and 65 bar, respectively) as compared to benchmark microporous MOFs.

  4. Recent Advances as Materials of Functional Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Xiao-Lan Tong

    2013-01-01

    Full Text Available Metal-organic frameworks (MOFs, also known as hybrid inorganic-organic materials, represent an emerging class of materials that have attracted the imagination of solid-state chemists because MOFs combine unprecedented levels of porosity with a range of other functional properties that occur through the metal moiety and/or the organic ligand. The purpose of this critical review is to give a representative and comprehensive overview of the arising developments in the field of functional metal-organic frameworks, including luminescence, magnetism, and porosity through presenting examples. This review will be of interest to researchers and synthetic chemists attempting to design multifunctional MOFs.

  5. Metal-organic framework catalysts for selective cleavage of aryl-ether bonds

    Science.gov (United States)

    Allendorf, Mark D.; Stavila, Vitalie

    2017-08-01

    The present invention relates to methods of employing a metal-organic framework (MOF) as a catalyst for cleaving chemical bonds. In particular instances, the MOF results in selective bond cleavage that results in hydrogenolyzis. Furthermore, the MOF catalyst can be reused in multiple cycles. Such MOF-based catalysts can be useful, e.g., to convert biomass components.

  6. Multifunctional Metal-Organic Frameworks for Photocatalysis.

    Science.gov (United States)

    Wang, Sibo; Wang, Xinchen

    2015-07-01

    Metal-organic frameworks (MOFs) have attracted significant research attention in diverse areas due to their unique physical and chemical characteristics that allow their innovative application in various research fields. Recently, the application of MOFs in heterogeneous photocatalysis for water splitting, CO2 reduction, and organic transformation have emerged, aiming at providing alternative solutions to address the world-wide energy and environmental problems by taking advantage of the unique porous structure together with ample physicochemical properties of the metal centers and organic ligands in MOFs. In this review, the latest progress in MOF-involved solar-to-chemical energy conversion reactions are summarized according to their different roles in the photoredox chemical systems, e.g., photocatalysts, co-catalysts, and hosts. The achieved progress and existing problems are evaluated and proposed, and the opportunities and challenges of MOFs and their related materials for their advanced development in photocatalysis are discussed and anticipated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Nanomaterials derived from metal-organic frameworks

    Science.gov (United States)

    Dang, Song; Zhu, Qi-Long; Xu, Qiang

    2018-01-01

    The thermal transformation of metal-organic frameworks (MOFs) generates a variety of nanostructured materials, including carbon-based materials, metal oxides, metal chalcogenides, metal phosphides and metal carbides. These derivatives of MOFs have characteristics such as high surface areas, permanent porosities and controllable functionalities that enable their good performance in sensing, gas storage, catalysis and energy-related applications. Although progress has been made to tune the morphologies of MOF-derived structures at the nanometre scale, it remains crucial to further our knowledge of the relationship between morphology and performance. In this Review, we summarize the synthetic strategies and optimized methods that enable control over the size, morphology, composition and structure of the derived nanomaterials. In addition, we compare the performance of materials prepared by the MOF-templated strategy and other synthetic methods. Our aim is to reveal the relationship between the morphology and the physico-chemical properties of MOF-derived nanostructures to optimize their performance for applications such as sensing, catalysis, and energy storage and conversion.

  8. Text Mining Metal-Organic Framework Papers.

    Science.gov (United States)

    Park, Sanghoon; Kim, Baekjun; Choi, Sihoon; Boyd, Peter G; Smit, Berend; Kim, Jihan

    2018-02-26

    We have developed a simple text mining algorithm that allows us to identify surface area and pore volumes of metal-organic frameworks (MOFs) using manuscript html files as inputs. The algorithm searches for common units (e.g., m 2 /g, cm 3 /g) associated with these two quantities to facilitate the search. From the sample set data of over 200 MOFs, the algorithm managed to identify 90% and 88.8% of the correct surface area and pore volume values. Further application to a test set of randomly chosen MOF html files yielded 73.2% and 85.1% accuracies for the two respective quantities. Most of the errors stem from unorthodox sentence structures that made it difficult to identify the correct data as well as bolded notations of MOFs (e.g., 1a) that made it difficult identify its real name. These types of tools will become useful when it comes to discovering structure-property relationships among MOFs as well as collecting a large set of data for references.

  9. Metal-organic frameworks for adsorption and separation of noble gases

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Greathouse, Jeffery A.; Staiger, Chad

    2017-05-30

    A method including exposing a gas mixture comprising a noble gas to a metal organic framework (MOF), including an organic electron donor and an adsorbent bed operable to adsorb a noble gas from a mixture of gases, the adsorbent bed including a metal organic framework (MOF) including an organic electron donor.

  10. Controlling Thermal Expansion: A Metal?Organic Frameworks Route

    OpenAIRE

    Balestra, Salvador R. G.; Bueno-Perez, Rocio; Hamad, Said; Dubbeldam, David; Ruiz-Salvador, A. Rabdel; Calero, Sofia

    2016-01-01

    Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal?organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model m...

  11. Post-assembly transformations of porphyrin-containing metal-organic framework (MOF) films fabricated via automated layer-by-layer coordination

    KAUST Repository

    So, Monica

    2015-01-01

    Herein, we demonstrate the robustness of layer-by-layer (LbL)-assembled, pillared-paddlewheel-type MOF films toward conversion to new or modified MOFs via solvent-assisted linker exchange (SALE) and post-assembly linker metalation. Further, we show that LbL synthesis can afford MOFs that have proven inaccessible through other de novo strategies.

  12. Multiferroic behavior associated with an order-disorder hydrogen bonding transition in metal-organic frameworks (MOFs) with the perovskite ABX3 architecture.

    Science.gov (United States)

    Jain, Prashant; Ramachandran, Vasanth; Clark, Ronald J; Zhou, Hai Dong; Toby, Brian H; Dalal, Naresh S; Kroto, Harold W; Cheetham, Anthony K

    2009-09-30

    Multiferroic behavior in perovskite-related metal-organic frameworks of general formula [(CH(3))(2)NH(2)]M(HCOO)(3), where M = Mn, Fe, Co, and Ni, is reported. All four compounds exhibit paraelectric-antiferroelectric phase transition behavior in the temperature range 160-185 K (Mn: 185 K, Fe: 160 K; Co: 165 K; Ni: 180 K); this is associated with an order-disorder transition involving the hydrogen bonded dimethylammonium cations. On further cooling, the compounds become canted weak ferromagnets below 40 K. This research opens up a new class of multiferroics in which the electrical ordering is achieved by means of hydrogen bonding.

  13. Zirconium-based highly porous metal-organic framework (MOF-545) as an efficient adsorbent for vortex assisted-solid phase extraction of lead from cereal, beverage and water samples.

    Science.gov (United States)

    Tokalıoğlu, Şerife; Yavuz, Emre; Demir, Selçuk; Patat, Şaban

    2017-12-15

    In this study, zirconium-based highly porous metal-organic framework, MOF-545, was synthesized and characterized. The surface area of MOF-545 was found to be 2192m 2 /g. This adsorbent was used for the first time as an adsorbent for the vortex assisted-solid phase extraction of Pb(II) from cereal, beverage and water samples. Lead in solutions was determined by FAAS. The optimal experimental conditions were as follows: the amount of MOF-545, 10mg; pH of sample, 7; adsorption and elution time, 15min; and elution solvent, 2mL of 1molL -1 HCl. Under the optimal conditions of the method, the limit of detection, preconcentration factor and precision as RSD% were found to be 1.78μgL -1 , 125 and 2.6%, respectively. The adsorption capacity of the adsorbent for lead was found to be 73mgg -1 . The method was successfully verified by analyzing two certified reference materials (BCR-482 Lichen and SPS-WW1 Batch 114) and spiked chickpea, bean, wheat, lentil, cherry juice, mineral water, well water and wastewater samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Removal of chlorine gas by an amine functionalized metal-organic framework via electrophilic aromatic substitution.

    Science.gov (United States)

    DeCoste, Jared B; Browe, Matthew A; Wagner, George W; Rossin, Joseph A; Peterson, Gregory W

    2015-08-11

    Here we report the removal of chlorine gas from air via a reaction with an amine functionalized metal-organic framework (MOF). It is found that UiO-66-NH2 has the ability to remove 1.24 g of Cl2 per g of MOF via an electrophilic aromatic substitution reaction producing HCl, which is subsequently neutralized by the MOF.

  15. Methodologies for evaluation of metal-organic frameworks in separation applications

    NARCIS (Netherlands)

    Krishna, R.

    2015-01-01

    Metal-organic frameworks (MOFs) offer considerable potential for separating a wide variety of mixtures. For any given separation, there are several MOFs that could be employed. Therefore, there is a need for reliable procedures for screening and ranking MOFs with regard to their anticipated

  16. Metal-organic frameworks based membranes for liquid separation.

    Science.gov (United States)

    Li, Xin; Liu, Yuxin; Wang, Jing; Gascon, Jorge; Li, Jiansheng; Van der Bruggen, Bart

    2017-11-27

    Metal-organic frameworks (MOFs) represent a fascinating class of solid crystalline materials which can be self-assembled in a straightforward manner by the coordination of metal ions or clusters with organic ligands. Owing to their intrinsic porous characteristics, unique chemical versatility and abundant functionalities, MOFs have received substantial attention for diverse industrial applications, including membrane separation. Exciting research activities ranging from fabrication strategies to separation applications of MOF-based membranes have appeared. Inspired by the marvelous achievements of MOF-based membranes in gas separations, liquid separations are also being explored for the purpose of constructing continuous MOFs membranes or MOF-based mixed matrix membranes. Although these are in an emerging stage of vigorous development, most efforts are directed towards improving the liquid separation efficiency with well-designed MOF-based membranes. Therefore, as an increasing trend in membrane separation, the field of MOF-based membranes for liquid separation is highlighted in this review. The criteria for judicious selection of MOFs in fabricating MOF-based membranes are given. Special attention is paid to rational design strategies for MOF-based membranes, along with the latest application progress in the area of liquid separations, such as pervaporation, water treatment, and organic solvent nanofiltration. Moreover, some attractive dual-function applications of MOF-based membranes in the removal of micropollutants, degradation, and antibacterial activity are also reviewed. Finally, we define the remaining challenges and future opportunities in this field. This Tutorial Review provides an overview and outlook for MOF-based membranes for liquid separations. Further development of MOF-based membranes for liquid separation must consider the demands of strict separation standards and environmental safety for industrial application.

  17. Green synthesis of chromium-based metal-organic framework (Cr-MOF) from waste polyethylene terephthalate (PET) bottles for hydrogen storage applications

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2016-10-01

    Full Text Available It is of great economic value to produce high-value PET-based MOF materials by the veritable elimination of waste PET, and provide sufficient MOF materials for hydrogen storage applications. Consequently, this work demonstrates the use of waste PET...

  18. Transformation of metal-organic frameworks for molecular sieving membranes.

    Science.gov (United States)

    Li, Wanbin; Zhang, Yufan; Zhang, Congyang; Meng, Qin; Xu, Zehai; Su, Pengcheng; Li, Qingbiao; Shen, Chong; Fan, Zheng; Qin, Lei; Zhang, Guoliang

    2016-04-19

    The development of simple, versatile strategies for the synthesis of metal-organic framework (MOF)-derived membranes are of increasing scientific interest, but challenges exist in understanding suitable fabrication mechanisms. Here we report a route for the complete transformation of a series of MOF membranes and particles, based on multivalent cation substitution. Through our approach, the effective pore size can be reduced through the immobilization of metal salt residues in the cavities, and appropriate MOF crystal facets can be exposed, to achieve competitive molecular sieving capabilities. The method can also be used more generally for the synthesis of a variety of MOF membranes and particles. Importantly, we design and synthesize promising MOF membranes candidates that are hard to achieve through conventional methods. For example, our CuBTC/MIL-100 membrane exhibits 89, 171, 241 and 336 times higher H2 permeance than that of CO2, O2, N2 and CH4, respectively.

  19. Hydrogen Storage in Metal-Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Long, Jeffrey R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-04-28

    The design and characterization of new materials for hydrogen storage is an important area of research, as the ability to store hydrogen at lower pressures and higher temperatures than currently feasible would lower operating costs for small hydrogen fuel cell vehicles. In particular, metal-organic frameworks (MOFs) represent promising materials for use in storing hydrogen in this capacity. MOFs are highly porous, three-dimensional crystalline solids that are formed via linkages between metal ions (e.g., iron, nickel, and zinc) and organic molecules. MOFs can store hydrogen via strong adsorptive interactions between the gas molecules and the pores of the framework, providing a high surface area for gas adsorption and thus the opportunity to store hydrogen at significantly lower pressures than with current technologies. By lowering the energy required for hydrogen storage, these materials hold promise in rendering hydrogen a more viable fuel for motor vehicles, which is a highly desirable outcome given the clean nature of hydrogen fuel cells (water is the only byproduct of combustion) and the current state of global climate change resulting from the combustion of fossil fuels. The work presented in this report is the result of collaborative efforts between researchers at Lawrence Berkeley National Lab (LBNL), the National Institute of Standards and Technology (NIST), and General Motors Corporation (GM) to discover novel MOFs promising for H2 storage and characterize their properties. Described herein are several new framework systems with improved gravimetric and volumetric capacity to strongly bind H2 at temperatures relevant for vehicle storage. These materials were rigorously characterized using neutron diffraction, to determine the precise binding locations of hydrogen within the frameworks, and high-pressure H2 adsorption measurements, to provide a comprehensive picture of H2 adsorption at all relevant pressures. A

  20. Metal-organic frameworks for lithium ion batteries and supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Fu-Sheng; Wu, Yu-Shan; Deng, Hexiang, E-mail: hdeng@whu.edu.cn

    2015-03-15

    Porous materials have been widely used in batteries and supercapacitors attribute to their large internal surface area (usually 100–1000 m{sup 2} g{sup −1}) and porosity that can favor the electrochemical reaction, interfacial charge transport, and provide short diffusion paths for ions. As a new type of porous crystalline materials, metal-organic frameworks (MOFs) have received huge attention in the past decade due to their unique properties, i.e. huge surface area (up to 7000 m{sup 2} g{sup −1}), high porosity, low density, controllable structure and tunable pore size. A wide range of applications including gas separation, storage, catalysis, and drug delivery benefit from the recent fast development of MOFs. However, their potential in electrochemical energy storage has not been fully revealed. Herein, the present mini review appraises recent and significant development of MOFs and MOF-derived materials for rechargeable lithium ion batteries and supercapacitors, to give a glimpse into these potential applications of MOFs. - Graphical abstract: MOFs with large surface area and high porosity can offer more reaction sites and charge carriers diffusion path. Thus MOFs are used as cathode, anode, electrolyte, matrix and precursor materials for lithium ion battery, and also as electrode and precursor materials for supercapacitors. - Highlights: • MOFs have potential in electrochemical area due to their high porosity and diversity. • We summarized and compared works on MOFs for lithium ion battery and supercapacitor. • We pointed out critical challenges and provided possible solutions for future study.

  1. High-internal-phase emulsions stabilized by metal-organic frameworks and derivation of ultralight metal-organic aerogels

    Science.gov (United States)

    Zhang, Bingxing; Zhang, Jianling; Liu, Chengcheng; Peng, Li; Sang, Xinxin; Han, Buxing; Ma, Xue; Luo, Tian; Tan, Xiuniang; Yang, Guanying

    2016-02-01

    To design high-internal-phase emulsion (HIPE) systems is of great interest from the viewpoints of both fundamental researches and practical applications. Here we demonstrate for the first time the utilization of metal-organic framework (MOF) for HIPE formation. By stirring the mixture of water, oil and MOF at room temperature, the HIPE stabilized by the assembly of MOF nanocrystals at oil-water interface could be formed. The MOF-stabilized HIPE provides a novel route to produce highly porous metal-organic aerogel (MOA) monolith. After removing the liquids from the MOF-stabilized HIPE, the ultralight MOA with density as low as 0.01 g·cm-3 was obtained. The HIPE approach for MOA formation has unique advantages and is versatile in producing different kinds of ultralight MOAs with tunable porosities and structures.

  2. Shock Wave Energy Dissipation by Metal-Organic Framework

    Science.gov (United States)

    Zhou, Xuan; Miao, Yurun; Banlusan, Kiettipong; Shaw, William; Strachan, Alejandro; Suslick, Kenneth; Dlott, Dana

    2017-06-01

    Metal-organic framework (MOF) such as ZIF-8 and UiO-66 show promising shock energy dissipation abilities through mechano-chemical reactions including bond breaking and pore collapse. In this work, we performed quantitative measurements on the shock wave energy attenuated by MOF films using a laser-driven flyer-plate apparatus. Aluminum flyer plates of 75-um thick were accelerated to speeds up to 2.0 km/s by a flat-top pulsed laser to impact the MOF film. The MOF layer was coated on a 200-nm thick gold mirror, which was deposited previously on glass substrate. Photonic Doppler velocimetry (PDV) was used to track the motions of the gold mirror, which can be converted to the energy flux and fluence of the shock wave that transmitted through the MOF layer. We deduced the shock energy that was attenuated by the MOF film by comparing the transmitted energy flux/fluence obtained with and without the presence of the MOF layer. A two-wave-shaped flux-time curve was obtained with the MOF layer because of its nanoporous structure. Studies on the shock wave energy attenuation by ZIF-8 and UiO-66 were carried out under various flyer speeds and sample thicknesses. We used in situ emission spectroscopy to verify that pore collapse was accompanied by chemical bond breakage. Corresponding author:dlott@illinois.edu.

  3. Applications of Total Scattering & Pair Distribution Function Analysis in Metal-Organic Framework Materials

    DEFF Research Database (Denmark)

    Xu, Hui; Birgisson, Steinar; Sommer, Sanna

    Metal-Organic Frameworks (MOFs) is constructed by metal-oxide nodes and organic ligands. The formation of different structures of metal-oxide nodes (also called secondary building units, SBU) is crucial for MOF final structures, because the connectivity of SBU greatly influence the final MOF...... structure. At the same time, there is an ongoing debate on whether the SBU is present prior, or during MOF crystallization in MOF chemistry. However, little is known about MOFs formation mechanism. Currently techniques to study the in situ MOF formation process mainly focused on after......-crystallization process, for example in situ XRD and SAXS/WAXS study on MOF formation. However, the pre-crystallization process in the early stage of MOF formation is still unexplored. In this project, total scattering and PDF study will be carried out to explore the MOF formation process in early stage. This includes...

  4. An overview of hydrogen storage materials: Making a case for metal organic frameworks

    CSIR Research Space (South Africa)

    Langmi, Henrietta W

    2013-04-01

    Full Text Available attention. In the past decade, there has been growing interest in metal organic frameworks (MOFs) as hydrogen storage materials due to their well-defined structure, tunability, high porosity and large specific surface area. This presentation provides...

  5. Functionalization of silicon nanowire surfaces with metal-organic frameworks

    KAUST Repository

    Liu, Nian

    2011-12-28

    Metal-organic frameworks (MOFs) and silicon nanowires (SiNWs) have been extensively studied due to their unique properties; MOFs have high porosity and specific surface area with well-defined nanoporous structure, while SiNWs have valuable one-dimensional electronic properties. Integration of the two materials into one composite could synergistically combine the advantages of both materials and lead to new applications. We report the first example of a MOF synthesized on surface-modified SiNWs. The synthesis of polycrystalline MOF-199 (also known as HKUST-1) on SiNWs was performed at room temperature using a step-by-step (SBS) approach, and X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy elemental mapping were used to characterize the material. Matching of the SiNW surface functional groups with the MOF organic linker coordinating groups was found to be critical for the growth. Additionally, the MOF morphology can by tuned by changing the soaking time, synthesis temperature and precursor solution concentration. This SiNW/MOF hybrid structure opens new avenues for rational design of materials with novel functionalities. © 2011 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

  6. Structural versatility of Metal-organic frameworks: Synthesis and Characterization

    KAUST Repository

    Alsadun, Norah S.

    2017-05-01

    Metal-Organic Frameworks (MOFs), an emerging class of porous crystalline materials, have shown promising properties for diverse applications such as catalysis, gas storage and separation. The high degree of tunability of MOFs vs other solid materials enable the assembly of advanced materials with fascinating properties for specific applications. Nevertheless, the precise control in the construction of MOFs at the molecular level remains challenging. Particularly, the formation of pre-targeted multi-nuclear Molecular Building Block (MBB) precursors to unveil materials with targeted structural characteristics is captivating. The aim of my master project in the continuous quest of the group of Prof. Eddaoudi in exploring different synthetic pathways to control the assembly of Rare Earth (RE) based MOF. After giving a general overview about MOFs, I will discuss in this thesis the results of my work on the use of tri-topic oriented organic carboxylate building units with the aim to explore the assembly/construction of new porous RE based MOFs. In chapter 2 will discuss the assembly of 3-c linkers with RE metals was then evaluated based on symmetry and angularity of the three connected linkers. The focus of chapter 3 is cerium based MOFs and heterometallic system, based on 3-c ligands with different length and symmetry. Overall, the incompatibility of 3-c ligands with the 12-c cuo MBB did not allow to any formation of higher neuclearity (˃6), but it has resulted in affecting the connectivity of the cluster.

  7. A Kind of Energy Storage Technology: Metal Organic Frameworks

    OpenAIRE

    Ozturk, Zeynel; Kose, D. A.; Asan, A.; Ozturk, B.

    2016-01-01

    For last fifteen years energy has been transferred by using electricity and as an energy carrier media electricity has some disadvantages like its wire need for transportation and its being non-storable for large amounts. To store more energy safely and for transportation it easily, new storing medias and devices are needed. For easy and safe energy transport there are many technologies and some of these contain hydrogen energy. Metal hydrides, carbon nanotubes, metal organic frameworks (MOFs...

  8. Nano-architecture of metal-organic frameworks

    Science.gov (United States)

    Milichko, Valentin A.; Zalogina, Anastasiia; Mingabudinova, Leila R.; Vinogradov, Alexander V.; Ubyivovk, Evgeniy; Krasilin, Andrei A.; Mukhin, Ivan; Zuev, Dmitry A.; Makarov, Sergey V.; Pidko, Evgeny A.

    2017-09-01

    Change the shape and size of materials supports new functionalities never found in the sources. This strategy has been recently applied for porous crystalline materials - metal-organic frameworks (MOFs) to create hollow nanoscale structures or mesostructures with improved functional properties. However, such structures are characterized by amorphous state or polycrystallinity which limits their applicability. Here we follow this strategy to create such nano- and mesostructures with perfect crystallinity and new photonics functionalities by laser or focused ion beam fabrication.

  9. Structural Origins of Scintillation: Metal Organic Frameworks as a Nanolaboratory

    Science.gov (United States)

    2016-06-01

    discrimination (PSD), for which the prompt component of the scintillation response is quenched for high specific energy loss (dE/dX) particles such as protons...for neutron discrimination (LDRD, $250k/year, FY10) - MOF-based scintillators (NA-22, ~600k / year, FY10-FY12) - Triplet-Harvesting doped plastic ...Structural Origins of Scintillation : Metal Organic Frameworks as a Nanolaboratory Distribution Statement A. Approved for public release

  10. A metal-organic framework nanocomposite made from functionalized magnetite nanoparticles and HKUST-1 (MOF-199) for preconcentration of Cd(II), Pb(II), and Ni(II)

    International Nuclear Information System (INIS)

    Ghorbani-Kalhor, Ebrahim

    2016-01-01

    The author describes the preparation of a magnetic metal organic framework of type MOF-199 containing magnetite (Fe 3 O 4 ) nanoparticles carrying covalently immobilized 4-(thiazolylazo) resorcinol (Fe 3 O 4 -TAR). This material is shown to represent a viable sorbent for separation and preconcentration of Cd(II), Pb(II), and Ni(II) ions. Box-Behnken design was applied to optimize the parameters affecting preconcentration. Following elution with 0.6 mol L −1 EDTA, the ions were quantified by FAAS. The capacity of the sorbent ranged between 185 and 210 mg g −1 . The limits of detection are 0.15, 0.40, and 0.8 ng mL −1 for Cd(II), Ni(II), and Pb(II) ions, respectively. The relative standard deviations are <8.5 %. The method was successfully applied to the rapid extraction of trace amounts of these ions from sea food and agri food. (author)

  11. Channeling and electromagnetic radiation of relativistic charged particles in metal-organic frameworks

    Science.gov (United States)

    Zhevago, N. K.; Glebov, V. I.

    2017-06-01

    We have developed the theory of electromagnetic interaction of relativistic charged particles with metal-organic frameworks (MOFs). The electrostatic potential and electron number density distribution in MOFs were calculated using the most accurate data for the atomic form factors. Peculiarities of axial channeling of fast charged particles and various types of electromagnetic radiation from relativistic particles has been discussed.

  12. Porphyrin-Based Metal-Organic Frameworks as Heterogeneous Catalysts in Oxidation Reactions

    Directory of Open Access Journals (Sweden)

    Carla F. Pereira

    2016-10-01

    Full Text Available Porphyrin-based Metal-Organic Frameworks (Por-MOFs constitute a special branch of the wide MOF family that has proven its own value and high potential in different applications. In this mini-review the application of these materials as catalysts in oxidation reactions is highlighted.

  13. Lanthanide-Based Metal Organic Frameworks: Synthetic Strategies and Catalytic Applications

    NARCIS (Netherlands)

    Pagis, C.; Ferbinteanu, M.; Rothenberg, G.; Grecea, S.

    2016-01-01

    This short critical review outlines the main synthetic strategies used in the designed synthesis of lanthanide-based metal organic frameworks (Ln-MOFs). It explains the impact of the choice of organic linker on the final network topology, and it highlights the applications of Ln-MOFs in the

  14. The Functionalization, Size Control and Properties of Metal-Organic Frameworks

    DEFF Research Database (Denmark)

    Xu, Hui; Iversen, Bo Brummerstedt

    Recent years, Metal-Organic Framework (MOF) materials have drawn great attentions due to their potential applications in gas sorption/separation and luminescent sensing. In this dissertation, the recent progress of MOF materials is reviewed, with specific focus on the functionalization, size...... control and properties of MOF materials. A cationic MOF material was synthesized, and small hydrocarbons C1/C2 sorption/separation properties were studied. A MOF with both open metal sites and Lewis basic pyridyl sites was developed, and C2H2, CO2 and CH4 gas sorption/separation properties were explored...

  15. A high rotational barrier for physisorbed hydrogen in an fcu-metal-organic framework

    KAUST Repository

    Pham, Tony T.

    2014-01-01

    A combined inelastic neutron scattering (INS) and theoretical study of H2 sorption in Y-FTZB, a recently reported metal-organic framework (MOF) with fcu topology, reveals that the strongest binding site in the MOF causes a high barrier to rotation on the sorbed H2. This rotational barrier for H2 is the highest yet of reported MOF materials based on physisorption. This journal is

  16. Gas adsorption on metal-organic frameworks

    Science.gov (United States)

    Willis, Richard R [Cary, IL; Low, John J. , Faheem, Syed A.; Benin, Annabelle I [Oak Forest, IL; Snurr, Randall Q [Evanston, IL; Yazaydin, Ahmet Ozgur [Evanston, IL

    2012-07-24

    The present invention involves the use of certain metal organic frameworks that have been treated with water or another metal titrant in the storage of carbon dioxide. The capacity of these frameworks is significantly increased through this treatment.

  17. Metal-adeninate vertices for the construction of an exceptionally porous metal-organic framework.

    Science.gov (United States)

    An, Jihyun; Farha, Omar K; Hupp, Joseph T; Pohl, Ehmke; Yeh, Joanne I; Rosi, Nathaniel L

    2012-01-03

    Metal-organic frameworks comprising metal-carboxylate cluster vertices and long, branched organic linkers are the most porous materials known, and therefore have attracted tremendous attention for many applications, including gas storage, separations, catalysis and drug delivery. To increase metal-organic framework porosity, the size and complexity of linkers has increased. Here we present a promising alternative strategy for constructing mesoporous metal-organic frameworks that addresses the size of the vertex rather than the length of the organic linker. This approach uses large metal-biomolecule clusters, in particular zinc-adeninate building units, as vertices to construct bio-MOF-100, an exclusively mesoporous metal-organic framework. Bio-MOF-100 exhibits a high surface area (4,300 m(2) g(-1)), one of the lowest crystal densities (0.302 g cm(-3)) and the largest metal-organic framework pore volume reported to date (4.3 cm(3) g(-1)).

  18. Cytotoxicity of nanoscaled metal-organic frameworks

    OpenAIRE

    Tamames-Tabar, Cristina; Cunha, Denise; Imbuluzqueta, Edurne; Ragon, Florence; Serre, Christian; Blanco-Prieto, Maria J.; Horcajada, Patricia

    2014-01-01

    A series of fourteen porous Metal–Organic Frameworks (MOFs) with different compositions (Fe, Zn, and Zr; carboxylates or imidazolates) and structures have been successfully synthesised at the nanoscale and fully characterised by XRPD, FTIR, TGA, N2 porosimetry, TEM, DLS and z-potential. Their toxicological assessment was performed using two different cell lines: human epithelial cells from foetal cervical carcinoma (HeLa) and murine macrophage cell line (J774). It appears that MOF...

  19. Three Novel Lanthanide Metal-Organic Frameworks (Ln-MOFs Constructed by Unsymmetrical Aromatic Dicarboxylatic Tectonics: Synthesis, Crystal Structures and Luminescent Properties

    Directory of Open Access Journals (Sweden)

    Ya-Pan Wu

    2014-09-01

    Full Text Available Three novel Ln(III-based coordination polymers, {[Ln2 (2,4-bpda3 (H2Ox]·yH2O}n (Ln = La (III (1, x = 2, y = 0, Ce (III (2, Pr (III (3, x = 4, y = 1 (2,4-H2bpda = benzophenone-2,4-dicarboxylic acid have been prepared via a solvothermal method and characterized by elemental analysis, IR, and single-crystal X-ray diffraction techniques. Complex 1 exhibits a 3D complicated framework with a new 2-nodal (3,7-connected (42·5 (44·51·66·8 topology. Complexes 2 and 3 are isomorphous, and feature a 3D 4-connected (65·8-CdSO4 network. Moreover, solid-state properties such as thermal stabilities and luminescent properties of 1 and 2 were also investigated. Complex 1 crystallized in a monoclinic space group P21/c with a = 14.800 (3, b = 14.500 (3, c = 18.800 (4 Å, β = 91.00 (3, V = 4033.9 (14 Å3 and Z = 4. Complex 2 crystallized in a monoclinic space group Cc with a = 13.5432 (4, b = 12.9981 (4, c = 25.7567 (11 Å, β = 104.028 (4, V = 1374.16 (7 Å3 and Z = 4.

  20. Nanoscale luminescent lanthanide-based metal-organic frameworks: properties, synthesis, and applications

    Science.gov (United States)

    Hu, Dongqin; Song, Yonghai; Wang, Li

    2015-07-01

    Nanoscale luminescent lanthanide-based metal-organic frameworks (NLLn-MOFs) possess superior optical and physical properties such as higher luminescent lifetime, quantum yield, high stability, high surface area, high agent loading, and intrinsic biodegradability, and therefore are regarded as a novel generation of luminescent material compared with bulk lanthanide-based metal-organic frameworks (Ln-MOFs). Traditional luminescent Ln-MOFs have been well studied; however, NLLn-MOFs taking the advantages of nanomaterials have attracted extensive investigations for applications in optical imaging in living cells, light-harvesting, and sensing. In this review, we provide a survey of the latest progresses made in developing NLLn-MOFs, which contains the fundamental optical features, synthesis, and their potential applications. Finally, the future prospects and challenges of the rapidly growing field are summarized.

  1. Ordered macro-microporous metal-organic framework single crystals

    Science.gov (United States)

    Shen, Kui; Zhang, Lei; Chen, Xiaodong; Liu, Lingmei; Zhang, Daliang; Han, Yu; Chen, Junying; Long, Jilan; Luque, Rafael; Li, Yingwei; Chen, Banglin

    2018-01-01

    We constructed highly oriented and ordered macropores within metal-organic framework (MOF) single crystals, opening up the area of three-dimensional–ordered macro-microporous materials (that is, materials containing both macro- and micropores) in single-crystalline form. Our methodology relies on the strong shaping effects of a polystyrene nanosphere monolith template and a double-solvent–induced heterogeneous nucleation approach. This process synergistically enabled the in situ growth of MOFs within ordered voids, rendering a single crystal with oriented and ordered macro-microporous structure. The improved mass diffusion properties of such hierarchical frameworks, together with their robust single-crystalline nature, endow them with superior catalytic activity and recyclability for bulky-molecule reactions, as compared with conventional, polycrystalline hollow, and disordered macroporous ZIF-8.

  2. Ordered macro-microporous metal-organic framework single crystals

    KAUST Repository

    Shen, Kui

    2018-01-16

    We constructed highly oriented and ordered macropores within metal-organic framework (MOF) single crystals, opening up the area of three-dimensional-ordered macro-microporous materials (that is, materials containing both macro- and micropores) in single-crystalline form. Our methodology relies on the strong shaping effects of a polystyrene nanosphere monolith template and a double-solvent-induced heterogeneous nucleation approach. This process synergistically enabled the in situ growth of MOFs within ordered voids, rendering a single crystal with oriented and ordered macro-microporous structure. The improved mass diffusion properties of such hierarchical frameworks, together with their robust single-crystalline nature, endow them with superior catalytic activity and recyclability for bulky-molecule reactions, as compared with conventional, polycrystalline hollow, and disordered macroporous ZIF-8.

  3. Energy transfer from quantum dots to metal-organic frameworks for enhanced light harvesting.

    Science.gov (United States)

    Jin, Shengye; Son, Ho-Jin; Farha, Omar K; Wiederrecht, Gary P; Hupp, Joseph T

    2013-01-23

    Because of their efficient energy-transport properties, porphyrin-based metal-organic frameworks (MOFs) are attractive compounds for solar photochemistry applications. However, their absorption bands provide limited coverage in the visible spectral range for light-harvesting applications. We report here the functionalization of porphyrin-based MOFs with CdSe/ZnS core/shell quantum dots (QDs) for the enhancement of light harvesting via energy transfer from the QDs to the MOFs. The broad absorption band of the QDs in the visible region offers greater coverage of the solar spectrum by QD-MOF hybrid structures. We show through time-resolved emission studies that photoexcitation of the QDs is followed by energy transfer to the MOFs with efficiencies of more than 80%. This sensitization approach can result in a >50% increase in the number of photons harvested by a single monolayer MOF structure with a monolayer of QDs on the surface of the MOF.

  4. Construction of hierarchically porous metal-organic frameworks through linker labilization

    Science.gov (United States)

    Yuan, Shuai; Zou, Lanfang; Qin, Jun-Sheng; Li, Jialuo; Huang, Lan; Feng, Liang; Wang, Xuan; Bosch, Mathieu; Alsalme, Ali; Cagin, Tahir; Zhou, Hong-Cai

    2017-05-01

    A major goal of metal-organic framework (MOF) research is the expansion of pore size and volume. Although many approaches have been attempted to increase the pore size of MOF materials, it is still a challenge to construct MOFs with precisely customized pore apertures for specific applications. Herein, we present a new method, namely linker labilization, to increase the MOF porosity and pore size, giving rise to hierarchical-pore architectures. Microporous MOFs with robust metal nodes and pro-labile linkers were initially synthesized. The mesopores were subsequently created as crystal defects through the splitting of a pro-labile-linker and the removal of the linker fragments by acid treatment. We demonstrate that linker labilization method can create controllable hierarchical porous structures in stable MOFs, which facilitates the diffusion and adsorption process of guest molecules to improve the performances of MOFs in adsorption and catalysis.

  5. Pristine Metal-Organic Frameworks and their Composites for Energy Storage and Conversion.

    Science.gov (United States)

    Liang, Zibin; Qu, Chong; Guo, Wenhan; Zou, Ruqiang; Xu, Qiang

    2017-11-22

    Metal-organic frameworks (MOFs), a new class of crystalline porous organic-inorganic hybrid materials, have recently attracted increasing interest in the field of energy storage and conversion. Herein, recent progress of MOFs and MOF composites for energy storage and conversion applications, including photochemical and electrochemical fuel production (hydrogen production and CO 2 reduction), water oxidation, supercapacitors, and Li-based batteries (Li-ion, Li-S, and Li-O 2 batteries), is summarized. Typical development strategies (e.g., incorporation of active components, design of smart morphologies, and judicious selection of organic linkers and metal nodes) of MOFs and MOF composites for particular energy storage and conversion applications are highlighted. A broad overview of recent progress is provided, which will hopefully promote the future development of MOFs and MOF composites for advanced energy storage and conversion applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Metal-organic framework templated synthesis of porous inorganic materials as novel sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, Kathryn M. L.; Lin, Wenbin; Abney, Carter W.

    2017-03-21

    A novel metal-organic framework (MOF) templated process for the synthesis of highly porous inorganic sorbents for removing radionuclides, actinides, and heavy metals is disclosed. The highly porous nature of the MOFs leads to highly porous inorganic sorbents (such as oxides, phosphates, sulfides, etc) with accessible surface binding sites that are suitable for removing radionuclides from high level nuclear wastes, extracting uranium from acid mine drainage and seawater, and sequestering heavy metals from waste streams. In some cases, MOFs can be directly used for removing these metal ions as MOFs are converted to highly porous inorganic sorbents in situ.

  7. On-board co2 capture and storage with metal organic framework

    KAUST Repository

    Eddaoudi, Mohamed

    2016-03-17

    In general, this disclosure describes method of capturing and storing CO2 on a vehicle. The method includes contacting an vehicle exhaust gas with one or more of a first metal organic framework (MOF) composition sufficient to separate CO2 from the exhaust gas, contacting the separated CO2 with one or more of a second MOF composition sufficient to store the CO2 and wherein the one or more first MOF composition comprises one or more SIFSIX-n-M MOF and wherein M is a metal and n is 2 or 3. Embodiments also describe an apparatus or system for capturing and storing CO2 onboard a vehicle.

  8. Metal organic frameworks as a drug delivery system for flurbiprofen

    Directory of Open Access Journals (Sweden)

    AL Haydar M

    2017-09-01

    Full Text Available Muder AL Haydar,1,2 Hussein Rasool Abid,3,4 Bruce Sunderland,2 Shaobin Wang5,6 1Pharmaceutics Department, College of the Pharmacy, University of Kerbala, Kerbala, Iraq; 2Pharmaceutics Department, School of Pharmacy, Faculty of Health Sciences, Curtin University, Perth, WA, Australia; 3Department of Chemical Engineering, Curtin University, Perth, WA, Australia; 4College of Applied Medical Sciences, University of Kerbala, Kerbala, Iraq; 5School of Pharmacy, Faculty of Health Sciences, Curtin University, Perth, WA, Australia; 6Department of Chemical Engineering, School of Chemical and Petroleum Engineering, Faculty of Science and Engineering, Curtin University, Perth, WA, Australia Background: Metal organic frameworks (MOFs have attracted more attention in the last decade because of a suitable pore size, large surface area, and high pore volume. Developing biocompatible MOFs such as the MIL family as a drug delivery system is possible. Purpose: Flurbiprofen (FBP, a nonsteroidal anti-inflammatory agent, is practically insoluble in aqueous solution, and, therefore, needs suitable drug delivery systems. Different biocompatible MOFs such as Ca-MOF and Fe-MILs (53, 100, and 101 were synthesized and employed for FBP delivery. Patients and methods: A sample of 50 mg of each MOF was mixed and stirred for 24 h with 10 mL of 5 mg FBP in acetonitrile (40% in a sealed container. The supernatant of the mixture after centrifuging was analyzed by high-performance liquid chromatography to determine the loaded quantity of FBP on the MOF. The overnight-dried solid material after centrifuging the mixture was analyzed for loading percent using X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, nuclear magnetic resonance, and FBP release profile. Results: The loading values of FBP were achieved at 10.0%±1%, 20%±0.8%, 37%±2.3%, and 46%±3.1% on Ca-MOF, Fe-MIL-53, Fe-MIL-101, and Fe-MIL-100, respectively. The FBP release

  9. Increasing the Stability of Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Mathieu Bosch

    2014-01-01

    Full Text Available Metal-organic frameworks (MOFs are a new category of advanced porous materials undergoing study by many researchers for their vast variety of both novel structures and potentially useful properties arising from them. Their high porosities, tunable structures, and convenient process of introducing both customizable functional groups and unsaturated metal centers have afforded excellent gas sorption and separation ability, catalytic activity, luminescent properties, and more. However, the robustness and reactivity of a given framework are largely dependent on its metal-ligand interactions, where the metal-containing clusters are often vulnerable to ligand substitution by water or other nucleophiles, meaning that the frameworks may collapse upon exposure even to moist air. Other frameworks may collapse upon thermal or vacuum treatment or simply over time. This instability limits the practical uses of many MOFs. In order to further enhance the stability of the framework, many different approaches, such as the utilization of high-valence metal ions or nitrogen-donor ligands, were recently investigated. This review details the efforts of both our research group and others to synthesize MOFs possessing drastically increased chemical and thermal stability, in addition to exemplary performance for catalysis, gas sorption, and separation.

  10. General incorporation of diverse components inside metal-organic framework thin films at room temperature

    Science.gov (United States)

    Mao, Yiyin; Li, Junwei; Cao, Wei; Ying, Yulong; Hu, Pan; Liu, Yu; Sun, Luwei; Wang, Hongtao; Jin, Chuanhong; Peng, Xinsheng

    2014-11-01

    Porous metal-organic frameworks (MOFs) demonstrate great potential for numerous applications. Although hetero-functional components have been encapsulated within MOF crystalline particles, the uniform incorporation of functional species with different sizes, shapes and functions in MOF thin films with dual properties, especially at room temperature and without the degradation of the MOF framework, remains a significant challenge towards further enriching their functions for various purposes. Here we report a general method that can rapidly encapsulate diverse functional components, including small ions, micrometre-sized particles, inorganic nanoparticles and bioactive proteins, in MOF thin films at room temperature via a metal-hydroxide-nanostrand-assisted confinement technique. These functional component-encapsulated MOF composite thin films exhibit synergistic and size-selective catalytic, bio-electrochemical, conductive and flexible functionalities that are desirable for thin film devices, including catalytic membrane reactors, biosensors and flexible electronic devices.

  11. Surface nano-architecture of a metal-organic framework.

    Science.gov (United States)

    Makiura, Rie; Motoyama, Soichiro; Umemura, Yasushi; Yamanaka, Hiroaki; Sakata, Osami; Kitagawa, Hiroshi

    2010-07-01

    The rational assembly of ultrathin films of metal-organic frameworks (MOFs)--highly ordered microporous materials--with well-controlled growth direction and film thickness is a critical and as yet unrealized issue for enabling the use of MOFs in nanotechnological devices, such as sensors, catalysts and electrodes for fuel cells. Here we report the facile bottom-up fabrication at ambient temperature of such a perfect preferentially oriented MOF nanofilm on a solid surface (NAFS-1), consisting of metalloporphyrin building units. The construction of NAFS-1 was achieved by the unconventional integration in a modular fashion of a layer-by-layer growth technique coupled with the Langmuir-Blodgett method. NAFS-1 is endowed with highly crystalline order both in the out-of-plane and in-plane orientations to the substrate, as demonstrated by synchrotron X-ray surface crystallography. The proposed structural model incorporates metal-coordinated pyridine molecules projected from the two-dimensional sheets that allow each further layer to dock in a highly ordered interdigitated manner in the growth of NAFS-1. We expect that the versatility of the solution-based growth strategy presented here will allow the fabrication of various well-ordered MOF nanofilms, opening the way for their use in a range of important applications.

  12. Luminescent multifunctional lanthanides-based metal-organic frameworks.

    Science.gov (United States)

    Rocha, João; Carlos, Luís D; Paz, Filipe A Almeida; Ananias, Duarte

    2011-02-01

    Metal-organic frameworks based on trivalent lanthanides (LnMOFs) are a very promising class of materials for addressing the challenges in engineering of luminescent centres. Lanthanide-bearing phosphors find numerous applications in lighting, optical communications, photonics and biomedical devices. In this critical review we discuss the potential of LnMOFs as multifunctional systems, which combine light emission with properties such as microporosity, magnetism, chirality, molecule and ion sensing, catalysis and activity as multimodal imaging contrast agents. We argue that these materials present a unique chance of observing synergy between several of these properties, such as the coupling between photoluminescence and magnetism. Moreover, an integrated approach towards the design of efficient, stable, cheap, environmentally-friendly and multifunctional luminescent LnMOFs is still missing. Although research into LnMOFs is at its early stage and much basic knowledge is still needed, the field is ripe for new ideas, which will enable sensor devices and photonic prototypes to become a commercial reality (81 references).

  13. Multirate delivery of multiple therapeutic agents from metal-organic frameworks

    Directory of Open Access Journals (Sweden)

    Alistair C. McKinlay

    2014-12-01

    Full Text Available The highly porous nature of metal-organic frameworks (MOFs offers great potential for the delivery of therapeutic agents. Here, we show that highly porous metal-organic frameworks can be used to deliver multiple therapeutic agents—a biologically active gas, an antibiotic drug molecule, and an active metal ion—simultaneously but at different rates. The possibilities offered by delivery of multiple agents with different mechanisms of action and, in particular, variable timescales may allow new therapy approaches. Here, we show that the loaded MOFs are highly active against various strains of bacteria.

  14. Ultrathin 2D Zirconium Metal-Organic Framework Nanosheets: Preparation and Application in Photocatalysis.

    Science.gov (United States)

    He, Ting; Ni, Bing; Zhang, Simin; Gong, Yue; Wang, Haiqing; Gu, Lin; Zhuang, Jing; Hu, Wenping; Wang, Xun

    2018-03-13

    Synthesizing ultrathin 2D metal-organic framework nanosheets in high yields has received increasing research interest but remains a great challenge. In this work, ultrathin zirconium-porphyrinic metal-organic framework (MOF) nanosheets with thickness down to ≈1.5 nm are synthesized through a pseudoassembly-disassembly strategy. Owing to the their unique properties originating from their ultrathin thickness and highly exposed active sites, the as-prepared ultrathin nanosheets exhibit far superior photocatalysis performance compared to the corresponding bulk MOF. This work highlights new opportunities in designing ultrathin MOF nanosheets and paves the way to expand the potential applications of MOFs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. In silico screening of metal-organic frameworks in separation applications

    NARCIS (Netherlands)

    Krishna, R.; van Baten, J.M.

    2011-01-01

    Porous materials such as metal-organic frameworks (MOFs) and zeolitic imidazolate frameworks (ZIFs) offer considerable potential for separating a variety of mixtures such as those relevant for CO2 capture (CO2/H2, CO2/CH4, CO2/N2), CH4/H2, alkanes/alkenes, and hydrocarbon isomers. There are

  16. Tunable photoluminescent metal-organic-frameworks and method of making the same

    Energy Technology Data Exchange (ETDEWEB)

    Nenoff, Tina M.; Sava Gallis, Dorina Florentina; Rohwer, Lauren E.S.

    2017-08-22

    The present disclosure is directed to new photoluminescent metal-organic frameworks (MOFs). The newly developed MOFs include either non rare earth element (REE) transition metal atoms or limited concentrations of REE atoms, including: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Ru, Ag, Cd, Sn, Sb, Ir, Pb, Bi, that are located in the MOF framework in site isolated locations, and have emission colors ranging from white to red, depending on the metal concentration levels and/or choice of ligand.

  17. Metal-Organic Framework-Stabilized CO2/Water Interfacial Route for Photocatalytic CO2Conversion.

    Science.gov (United States)

    Luo, Tian; Zhang, Jianling; Li, Wei; He, Zhenhong; Sun, Xiaofu; Shi, Jinbiao; Shao, Dan; Zhang, Bingxing; Tan, Xiuniang; Han, Buxing

    2017-11-29

    Here, we propose a CO 2 /water interfacial route for photocatalytic CO 2 conversion by utilizing a metal-organic framework (MOF) as both an emulsifier and a catalyst. The CO 2 reduction occurring at the CO 2 /water interface produces formate with remarkably enhanced efficiency as compared with that in conventional solvent. The route is efficient, facile, adjustable, and environmentally benign, which is applicable for the CO 2 transformation photocatalyzed by different kinds of MOFs.

  18. Preparation Methods of Metal Organic Frameworks and Their Capture of CO2

    Science.gov (United States)

    Zhang, Linjian; Liand, Fangqin; Luo, Liangfei

    2018-01-01

    The increasingly serious greenhouse effect makes people pay more attention to the capture and storage technology of CO2. Metal organic frameworks (MOFs) have the advantages of high specific surface area, porous structure and controllable structure, and become the research focus of CO2 emission reduction technology in recent years. In this paper, the characteristics, preparation methods and application of MOFs in the field of CO2 adsorption and separation are discussed, especially the application of flue gas environment in power plants.

  19. Metal Organic Framework: Crystalline Stacked Molecular Containers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 12. Metal Organic Framework: ... Ramanathan Vaidhyanathan. General Article Volume 19 Issue 12 December 2014 pp 1147-1157 ... Vaidhyanathan1. Department of Chemistry Indian Institute of Science Education and Research Pune, India.

  20. Magnetic behaviour in metal-organic frameworks

    Indian Academy of Sciences (India)

    The article describes the synthesis, structure and magnetic investigations of a series of metal-organic framework compounds formed with Mn+2 and Ni+2 ions. The structures, determined using the single crystal X-ray diffraction, indicated that the structures possess two- and three-dimensional structures with magnetically ...

  1. Screening metal-organic frameworks by analysis of transient breakthrough of gas mixtures in a fixed bed adsorber

    NARCIS (Netherlands)

    Krishna, R.; Long, J.R.

    2011-01-01

    Metal-organic frameworks (MOFs) offer considerable potential for separating a variety of mixtures that are important in applications such as CO2 capture and H2 purification. In view of the vast number of MOFs that have been synthesized, there is a need for a reliable procedure for comparing

  2. Mechanistic Insights into Growth of Surface-Mounted Metal-Organic Framework Films Resolved by Infrared (Nano-) Spectroscopy

    NARCIS (Netherlands)

    Delen, Guusje; Ristanovic, Zoran|info:eu-repo/dai/nl/328233005; Mandemaker, Laurens D. B.; Weckhuysen, Bert M.|info:eu-repo/dai/nl/285484397

    2018-01-01

    Control over assembly, orientation, and defect-free growth of metal-organic framework (MOF) films is crucial for their future applications. A layer-by-layer approach is considered a suitable method to synthesize highly oriented films of numerous MOF topologies, but the initial stages of the film

  3. Controlling Thermal Expansion: A Metal-Organic Frameworks Route.

    Science.gov (United States)

    Balestra, Salvador R G; Bueno-Perez, Rocio; Hamad, Said; Dubbeldam, David; Ruiz-Salvador, A Rabdel; Calero, Sofia

    2016-11-22

    Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal-organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model material, along with three molecules of similar size and known differences in terms of the nature of host-guest interactions. It has been shown that adsorbate molecules can control, in a colligative way, the thermal expansion of the solid, so that changing the adsorbate molecules induces the solid to display positive, zero, or negative thermal expansion. We analyze in depth the distortion mechanisms, beyond the ligand metal junction, to cover the ligand distortions, and the energetic and entropic effect on the thermo-structural behavior. We provide an unprecedented atomistic insight on the effect of adsorbates on the thermal expansion of MOFs as a basic tool toward controlling the thermal expansion.

  4. A Redox-Active Bistable Molecular Switch Mounted inside a Metal-Organic Framework.

    Science.gov (United States)

    Chen, Qishui; Sun, Junling; Li, Peng; Hod, Idan; Moghadam, Peyman Z; Kean, Zachary S; Snurr, Randall Q; Hupp, Joseph T; Farha, Omar K; Stoddart, J Fraser

    2016-11-02

    We describe the incorporation of a bistable mechanically interlocked molecule (MIM) into a robust Zr-based metal-organic framework (MOF), NU-1000, by employing a post-synthetic functionalization protocol. On average, close to two bistable [2]catenanes can be incorporated per repeating unit of the hexagonal channels of NU-1000. The reversible redox-switching of the bistable [2]catenanes is retained inside the MOF, as evidenced by solid-state UV-vis-NIR reflectance spectroscopy and cyclic voltammetry. This research demonstrates that bistable MIMs are capable of exhibiting robust dynamics inside the nanopores of a MOF.

  5. Hierarchical Pore Development by Plasma Etching of Zr-Based Metal-Organic Frameworks.

    Science.gov (United States)

    DeCoste, Jared B; Rossin, Joseph A; Peterson, Gregory W

    2015-12-07

    The typically stable Zr-based metal-organic frameworks (MOFs) UiO-66 and UiO-66-NH2 were treated with tetrafluoromethane (CF4 ) and hexafluoroethane (C2 F6 ) plasmas. Through interactions between fluoride radicals from the perfluoroalkane plasma and the zirconium-oxygen bonds of the MOF, the resulting materials showed the development of mesoporosity, creating a hierarchical pore structure. It is anticipated that this strategy can be used as a post-synthetic technique for developing hierarchical networks in a variety of MOFs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Hierarchical Structure and Molecular Dynamics of Metal-Organic Framework as Characterized by Solid State NMR

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2016-01-01

    Full Text Available Metal-organic framework (MOF stands out as a promising material with great potential in application areas, such as gas separation and catalysis, due to its extraordinary properties. In order to fully characterize the structure of MOFs, especially those without single crystal, Solid State NMR (SSNMR is an indispensable tool. As a complimentary analytical technique to X-ray diffraction, SSNMR could provide detailed atomic level structure information. Meanwhile, SSNMR can characterize molecular dynamics over a wide dynamics range. In this review, selected applications of SSNMR on various MOFs are summarized and discussed.

  7. Exceptional function of nanoporous metal organic framework particles in emulsion stabilisation.

    Science.gov (United States)

    Xiao, Bo; Yuan, Qingchun; Williams, Richard A

    2013-09-25

    A new concept of nanoporous metal organic framework particles stabilising emulsions was investigated. The copper benzenetricarboxylate MOF particles adsorbed at the oil/water interface play an exceptional role in stabilising both oil-in-water and water-in-oil emulsions.

  8. Metal-Organic Frameworks For Adsorption Driven Energy Transformation : From Fundamentals To Applications

    NARCIS (Netherlands)

    De Lange, M.F.

    2015-01-01

    A novel class of materials, i.e. Metal-Organic Frameworks (MOFs), has successfully been developed that is extremely suited for application in heat pumps and chillers. They have a superior performance over commercial sorbents and may potentially contribute to considerable energy savings worldwide.

  9. Expanded Organic Building Units for the Construction of Highly Porous Metal-Organic Frameworks

    NARCIS (Netherlands)

    Kong, G.Q.; Han, Z.D.; He, Y.; Qu, S.; Zhou, W.; Yildirim, T.; Krishna, R.; Zou, C.; Chen, B.; Wu, C.D.

    2013-01-01

    wo new organic building units that contain dicarboxylate sites for their self-assembly with paddlewheel [Cu2(CO2)4] units have been successfully developed to construct two isoreticular porous metal-organic frameworks (MOFs), ZJU-35 and ZJU-36, which have the same tbo topologies (Reticular Chemistry

  10. Metal organic frameworks as precursors for the manufacture of advanced catalytic materials

    NARCIS (Netherlands)

    Oar-Arteta Gonzalez, L.; Wezendonk, T.A.; Sun, X.; Kapteijn, F.; Gascon Sabate, J.

    The use of metal organic frameworks as hard templates for the preparation of heterogeneous catalysts is thoroughly reviewed. In this critical article, the main factors to consider when using a MOF as a sacrificial template are first discussed. Then, the existing literature on the topic is reviewed,

  11. Lipase-supported metal-organic framework bioreactor catalyzes warfarin synthesis.

    Science.gov (United States)

    Liu, Wan-Ling; Yang, Ni-Shin; Chen, Ya-Ting; Lirio, Stephen; Wu, Cheng-You; Lin, Chia-Her; Huang, Hsi-Ya

    2015-01-02

    A green and sustainable strategy synthesizes clinical medicine warfarin anticoagulant by using lipase-supported metal-organic framework (MOF) bioreactors (see scheme). These findings may be beneficial for future studies in the industrial production of chemical, pharmaceutical, and agrochemical precursors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Remote stabilization of copper paddlewheel based molecular building blocks in metal-organic frameworks

    KAUST Repository

    Gao, Wenyang

    2015-03-24

    Copper paddlewheel based molecular building blocks (MBBs) are ubiquitous and have been widely employed for the construction of highly porous metal-organic frameworks (MOFs). However, most copper paddlewheel based MOFs fail to retain their structural integrity in the presence of water. This instability is directly correlated to the plausible displacement of coordinating carboxylates in the copper paddlewheel MBB, [Cu2(O2C-)4], by the strongly coordinating water molecules. In this comprehensive study, we illustrate the chemical stability control in the rht-MOF platform via strengthening the coordinating bonds within the triangular inorganic MBB, [Cu3O(N4-x(CH)xC-)3] (x = 0, 1, or 2). Remotely, the chemical stabilization propagated into the paddlewheel MBB to afford isoreticular rht-MOFs with remarkably enhanced water/chemical stabilities compared to the prototypal rht-MOF-1. © 2015 American Chemical Society.

  13. The chemistry of metal-organic frameworks for CO2 capture, regeneration and conversion

    Science.gov (United States)

    Trickett, Christopher A.; Helal, Aasif; Al-Maythalony, Bassem A.; Yamani, Zain H.; Cordova, Kyle E.; Yaghi, Omar M.

    2017-08-01

    The carbon dioxide challenge is one of the most pressing problems facing our planet. Each stage in the carbon cycle — capture, regeneration and conversion — has its own materials requirements. Recent work on metal-organic frameworks (MOFs) demonstrated the potential and effectiveness of these materials in addressing this challenge. In this Review, we identify the specific structural and chemical properties of MOFs that have led to the highest capture capacities, the most efficient separations and regeneration processes, and the most effective catalytic conversions. The interior of MOFs can be designed to have coordinatively unsaturated metal sites, specific heteroatoms, covalent functionalization, other building unit interactions, hydrophobicity, porosity, defects and embedded nanoscale metal catalysts with a level of precision that is crucial for the development of higher-performance MOFs. To realize a total solution, it is necessary to use the precision of MOF chemistry to build more complex materials to address selectivity, capacity and conversion together in one material.

  14. Anodized Aluminum Oxide Templated Synthesis of Metal-Organic Frameworks Used as Membrane Reactors.

    Science.gov (United States)

    Yu, Yifu; Wu, Xue-Jun; Zhao, Meiting; Ma, Qinglang; Chen, Junze; Chen, Bo; Sindoro, Melinda; Yang, Jian; Han, Shikui; Lu, Qipeng; Zhang, Hua

    2017-01-09

    The incorporation of metal-organic frameworks (MOFs) into membrane-shaped architectures is of great importance for practical applications. The currently synthesized MOF-based membranes show many disadvantages, such as poor compatibility, low dispersity, and instability, which severely limit their utility. Herein, we present a general, facile, and robust approach for the synthesis of MOF-based composite membranes through the in situ growth of MOF plates in the channels of anodized aluminum oxide (AAO) membranes. After being used as catalysis reactors, they exhibit high catalytic performance and stability in the Knoevenagel condensation reaction. The high catalytic performance might be attributed to the intrinsic structure of MOF-based composite membranes, which can remove the products from the reaction zone quickly, and prevent the aggregation and loss of catalysts during reaction and recycling process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Compositions and methods of making and using metal-organic framework compositions

    KAUST Repository

    Mohideen, Mohamed Infas Haja

    2017-05-04

    Embodiments of the present disclosure include a metal-organic framework (MOF) composition comprising one or more metal ions, a plurality of organic ligands, and a solvent, wherein the one or more metal ions associate with the plurality of organic ligands sufficient to form a MOF with kag topology. Embodiments of the present disclosure further include a method of making a MOF composition comprising contacting one or more metal ions with a plurality of organic ligands in the presence of a solvent, sufficient to form a MOF with kag topology, wherein the solvent comprises water only. Embodiments of the present disclosure also describe a method of capturing chemical species from a fluid composition comprising contacting a MOF composition with kag topology and pore size of about 3.4Å to 4.8Å with a fluid composition comprising two or more chemical species and capturing one or more captured chemical species from the fluid composition.

  16. Antifungal activity of water-stable copper-containing metal-organic frameworks

    Science.gov (United States)

    Bouson, Supaporn; Krittayavathananon, Atiweena; Phattharasupakun, Nutthaphon; Siwayaprahm, Patcharaporn; Sawangphruk, Montree

    2017-10-01

    Although metal-organic frameworks (MOFs) or porous coordination polymers have been widely studied, their antimicrobial activities have not yet been fully investigated. In this work, antifungal activity of copper-based benzene-tricarboxylate MOF (Cu-BTC MOF), which is water stable and industrially interesting, is investigated against Candida albicans, Aspergillus niger, Aspergillus oryzae and Fusarium oxysporum. The Cu-BTC MOF can effectively inhibit the growth rate of C. albicans and remarkably inhibit the spore growth of A. niger, A. oryzae and F. oxysporum. This finding shows the potential of using Cu-BTC MOF as a strong biocidal material against representative yeasts and moulds that are commonly found in the food and agricultural industries.

  17. Single Pt Atoms Confined into a Metal-Organic Framework for Efficient Photocatalysis.

    Science.gov (United States)

    Fang, Xinzuo; Shang, Qichao; Wang, Yu; Jiao, Long; Yao, Tao; Li, Yafei; Zhang, Qun; Luo, Yi; Jiang, Hai-Long

    2018-02-01

    It is highly desirable yet remains challenging to improve the dispersion and usage of noble metal cocatalysts, beneficial to charge transfer in photocatalysis. Herein, for the first time, single Pt atoms are successfully confined into a metal-organic framework (MOF), in which electrons transfer from the MOF photosensitizer to the Pt acceptor for hydrogen production by water splitting under visible-light irradiation. Remarkably, the single Pt atoms exhibit a superb activity, giving a turnover frequency of 35 h -1 , ≈30 times that of Pt nanoparticles stabilized by the same MOF. Ultrafast transient absorption spectroscopy further unveils that the single Pt atoms confined into the MOF provide highly efficient electron transfer channels and density functional theory calculations indicate that the introduction of single Pt atoms into the MOF improves the hydrogen binding energy, thus greatly boosting the photocatalytic H 2 production activity. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Sonochemical Synthesis of Photoluminescent Nanoscale Eu(III-Containing Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Cheng-an TAO

    2015-11-01

    Full Text Available Nanoscale lanthanide-containing metal-organic frameworks (MOFs have more and more interest due to their great properties and potential applications, but how to construct them easily is still challenging. Here, we present a facile and rapid synthesis of Eu(III-containing Nanoscale MOF (denoted as NMOF under ultrasonic irradiation. The effect of the ratio and the addition order of metal ions and linkers on the morphology and size of MOFs was investigated. It is found that both of the ratio and the addition order can affect the morphology and size of 1.4-benzenedicarboxylic acid(H2BDC -based MOFs, but they show no evident influence on that of H2aBDC-based MOFs. The former exhibit typical emission bands of Eu(III ions, while the latter only show the photoluminescent properties of ligands.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9695

  19. Toxic effect of zinc nanoscale metal-organic frameworks on rat pheochromocytoma (PC12) cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Fei, E-mail: paper_mail@126.com [Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Yang, Baochun; Cai, Jing [Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Jiang, Yaodong [Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Xu, Jun [Department of Health Economy Administration, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Wang, Shan [Department of Pharmacy, Winthrop University Hospital, Mineola, NY 11501 (United States)

    2014-04-01

    Highlights: • Metal-organic frameworks (MOFs) represent a newborn family of hybrid materials. • MOFs have already shown promise in a number of biological applications. • The biological applications of MOFs raise concerns for potential cytotoxicity. • Substantial information about MOF's neurotoxicity is still quite scarce. • This study reveals for the first time the interaction of MOFs with neural cells. - Abstract: Metal-organic frameworks (MOFs) possess unique properties desirable for delivery of drugs and gaseous therapeutics, but their uncharacterized interactions with cells raise increasing concerns of their safety in such biomedical applications. We evaluated the adverse effects of zinc nanoscale MOFs on the cell morphology, cytoskeleton, cell viability and expression of neurotrophin signaling pathway-associated GAP-43 protein in rat pheochromocytoma PC12 cells. At the concentration of 25 μg/ml, zinc MOFs did not significantly affect morphology, viability and membrane integrity of the cells. But at higher concentrations (over 100 μg/ml), MOFs exhibited a time- and concentration-dependent cytotoxicity, indicating their entry into the cells via endocytosis where they release Zn{sup 2+} into the cytosol to cause increased intracellular concentration of Zn{sup 2+}. We demonstrated that the toxicity of MOFs was associated with a disrupted cellular zinc homeostasis and down-regulation of GAP-43 protein, which might be the underlying mechanism for the improved differentiation in PC12 cells. These findings highlight the importance of cytotoxic evaluation of the MOFs before their biomedical application.

  20. Metal-organic frameworks as selectivity regulators for hydrogenation reactions.

    Science.gov (United States)

    Zhao, Meiting; Yuan, Kuo; Wang, Yun; Li, Guodong; Guo, Jun; Gu, Lin; Hu, Wenping; Zhao, Huijun; Tang, Zhiyong

    2016-11-03

    Owing to the limited availability of natural sources, the widespread demand of the flavouring, perfume and pharmaceutical industries for unsaturated alcohols is met by producing them from α,β-unsaturated aldehydes, through the selective hydrogenation of the carbon-oxygen group (in preference to the carbon-carbon group). However, developing effective catalysts for this transformation is challenging, because hydrogenation of the carbon-carbon group is thermodynamically favoured. This difficulty is particularly relevant for one major category of heterogeneous catalyst: metal nanoparticles supported on metal oxides. These systems are generally incapable of significantly enhancing the selectivity towards thermodynamically unfavoured reactions, because only the edges of nanoparticles that are in direct contact with the metal-oxide support possess selective catalytic properties; most of the exposed nanoparticle surfaces do not. This has inspired the use of metal-organic frameworks (MOFs) to encapsulate metal nanoparticles within their layers or inside their channels, to influence the activity of the entire nanoparticle surface while maintaining efficient reactant and product transport owing to the porous nature of the material. Here we show that MOFs can also serve as effective selectivity regulators for the hydrogenation of α,β-unsaturated aldehydes. Sandwiching platinum nanoparticles between an inner core and an outer shell composed of an MOF with metal nodes of Fe 3+ , Cr 3+ or both (known as MIL-101; refs 19, 20, 21) results in stable catalysts that convert a range of α,β-unsaturated aldehydes with high efficiency and with significantly enhanced selectivity towards unsaturated alcohols. Calculations reveal that preferential interaction of MOF metal sites with the carbon-oxygen rather than the carbon-carbon group renders hydrogenation of the former by the embedded platinum nanoparticles a thermodynamically favoured reaction. We anticipate that our basic design

  1. Metal-organic frameworks: structure, properties, methods of synthesis and characterization

    International Nuclear Information System (INIS)

    Butova, V V; Soldatov, M A; Guda, A A; Lomachenko, K A; Lamberti, C

    2016-01-01

    This review deals with key methods of synthesis and characterization of metal-organic frameworks (MOFs). The modular structure affords a wide variety of MOFs with different active metal sites and organic linkers. These compounds represent a new stage of development of porous materials in which the pore size and the active site structure can be modified within wide limits. The set of experimental methods considered in this review is sufficient for studying the short-range and long-range order of the MOF crystal structure, determining the morphology of samples and elucidating the processes that occur at the active metal site in the course of chemical reactions. The interest in metal-organic frameworks results, first of all, from their numerous possible applications, ranging from gas separation and storage to chemical reactions within the pores. The bibliography includes 362 references

  2. Light-harvesting and ultrafast energy migration in porphyrin-based metal-organic frameworks.

    Science.gov (United States)

    Son, Ho-Jin; Jin, Shengye; Patwardhan, Sameer; Wezenberg, Sander J; Jeong, Nak Cheon; So, Monica; Wilmer, Christopher E; Sarjeant, Amy A; Schatz, George C; Snurr, Randall Q; Farha, Omar K; Wiederrecht, Gary P; Hupp, Joseph T

    2013-01-16

    Given that energy (exciton) migration in natural photosynthesis primarily occurs in highly ordered porphyrin-like pigments (chlorophylls), equally highly ordered porphyrin-based metal-organic frameworks (MOFs) might be expected to exhibit similar behavior, thereby facilitating antenna-like light-harvesting and positioning such materials for use in solar energy conversion schemes. Herein, we report the first example of directional, long-distance energy migration within a MOF. Two MOFs, namely F-MOF and DA-MOF that are composed of two Zn(II) porphyrin struts [5,15-dipyridyl-10,20-bis(pentafluorophenyl)porphinato]zinc(II) and [5,15-bis[4-(pyridyl)ethynyl]-10,20-diphenylporphinato]zinc(II), respectively, were investigated. From fluorescence quenching experiments and theoretical calculations, we find that the photogenerated exciton migrates over a net distance of up to ~45 porphyrin struts within its lifetime in DA-MOF (but only ~3 in F-MOF), with a high anisotropy along a specific direction. The remarkably efficient exciton migration in DA-MOF is attributed to enhanced π-conjugation through the addition of two acetylene moieties in the porphyrin molecule, which leads to greater Q-band absorption intensity and much faster exciton-hopping (energy transfer between adjacent porphyrin struts). The long distance and directional energy migration in DA-MOF suggests promising applications of this compound or related compounds in solar energy conversion schemes as an efficient light-harvesting and energy-transport component.

  3. Xenon Recovery at Room Temperature using Metal-Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Elsaidi, Sameh K. [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; Chemistry Department, Faculty of Science, Alexandria University, P. O. Box 426 Ibrahimia Alexandria 21321 Egypt; Ongari, Daniele [Laboratory of Molecular Simulation, Institut des Sciences et Ingeénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de l' Industrie 17 1951 Sion Valais Switzerland; Xu, Wenqian [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Mohamed, Mona H. [Chemistry Department, Faculty of Science, Alexandria University, P. O. Box 426 Ibrahimia Alexandria 21321 Egypt; Haranczyk, Maciej [IMDEA Materials Institute, c/Eric Kandel 2 28906 Getafe, Madrid Spain; Thallapally, Praveen K. [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA

    2017-07-24

    Xenon is known to be a very efficient anesthetic gas but its cost prohibits the wider use in medical industry and other potential applications. It has been shown that Xe recovery and recycle from anesthetic gas mixture can significantly reduce its cost as anesthetic. The current technology uses series of adsorbent columns followed by low temperature distillation to recover Xe, which is expensive to use in medical facilities. Herein, we propose much efficient and simpler system to recover and recycle Xe from simulant exhale anesthetic gas mixture at room temperature using metal organic frameworks. Among the MOFs tested, PCN-12 exhibits unprecedented performance with high Xe capacity, Xe/N2 and Xe/O2 selectivity at room temperature. The in-situ synchrotron measurements suggest the Xe is occupied in the small pockets of PCN-12 compared to unsaturated metal centers (UMCs). Computational modeling of adsorption further supports our experimental observation of Xe binding sites in PCN-12.

  4. Metal-organic frameworks: functional luminescent and photonic materials for sensing applications.

    Science.gov (United States)

    Lustig, William P; Mukherjee, Soumya; Rudd, Nathan D; Desai, Aamod V; Li, Jing; Ghosh, Sujit K

    2017-06-06

    Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) are open, crystalline supramolecular coordination architectures with porous facets. These chemically tailorable framework materials are the subject of intense and expansive research, and are particularly relevant in the fields of sensory materials and device engineering. As the subfield of MOF-based sensing has developed, many diverse chemical functionalities have been carefully and rationally implanted into the coordination nanospace of MOF materials. MOFs with widely varied fluorometric sensing properties have been developed using the design principles of crystal engineering and structure-property correlations, resulting in a large and rapidly growing body of literature. This work has led to advancements in a number of crucial sensing domains, including biomolecules, environmental toxins, explosives, ionic species, and many others. Furthermore, new classes of MOF sensory materials utilizing advanced signal transduction by devices based on MOF photonic crystals and thin films have been developed. This comprehensive review summarizes the topical developments in the field of luminescent MOF and MOF-based photonic crystals/thin film sensory materials.

  5. Chemistry of Metal-organic Frameworks Monitored by Advanced X-ray Diffraction and Scattering Techniques.

    Science.gov (United States)

    Mazaj, Matjaž; Kaučič, Venčeslav; Zabukovec Logar, Nataša

    2016-01-01

    The research on metal-organic frameworks (MOFs) experienced rapid progress in recent years due to their structure diversity and wide range of application opportunities. Continuous progress of X-ray and neutron diffraction methods enables more and more detailed insight into MOF's structural features and significantly contributes to the understanding of their chemistry. Improved instrumentation and data processing in high-resolution X-ray diffraction methods enables the determination of new complex MOF crystal structures in powdered form. By the use of neutron diffraction techniques, a lot of knowledge about the interaction of guest molecules with crystalline framework has been gained in the past few years. Moreover, in-situ time-resolved studies by various diffraction and scattering techniques provided comprehensive information about crystallization kinetics, crystal growth mechanism and structural dynamics triggered by external physical or chemical stimuli. The review emphasizes most relevant advanced structural studies of MOFs based on powder X-ray and neutron scattering.

  6. Liquid- and Gas-Phase Diffusion of Ferrocene in Thin Films of Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Wencai Zhou

    2015-06-01

    Full Text Available The mass transfer of the guest molecules in nanoporous host materials, in particular in metal-organic frameworks (MOFs, is among the crucial features of their applications. By using thin surface-mounted MOF films in combination with a quartz crystal microbalance (QCM, the diffusion of ferrocene vapor and of ethanolic and hexanic ferrocene solution in HKUST-1 was investigated. For the first time, liquid- and gas-phase diffusion in MOFs was compared directly in the identical sample. The diffusion coefficients are in the same order of magnitude (~10−16 m2·s−1, whereas the diffusion coefficient of ferrocene in the empty framework is roughly 3-times smaller than in the MOF which is filled with ethanol or n-hexane.

  7. Creating Hierarchical Pores by Controlled Linker Thermolysis in Multivariate Metal-Organic Frameworks

    KAUST Repository

    Feng, Liang

    2018-01-18

    Sufficient pore size, appropriate stability and hierarchical porosity are three prerequisites for open frameworks designed for drug delivery, enzyme immobilization and catalysis involving large molecules. Herein, we report a powerful and general strate-gy, linker thermolysis, to construct ultra-stable hierarchically porous metal−organic frameworks (HP-MOFs) with tunable pore size distribution. Linker instability, usually an undesirable trait of MOFs, was exploited to create mesopores by generating crystal defects throughout a microporous MOF crystal via thermolysis. The crystallinity and stability of HP-MOFs remain after thermolabile linkers are selectively removed from multivariate metal-organic frameworks (MTV-MOFs) through a decarboxyla-tion process. A domain-based linker spatial distribution was found to be critical for creating hierarchical pores inside MTV-MOFs. Furthermore, linker thermolysis promotes the formation of ultra-small metal oxide (MO) nanoparticles immobilized in an open framework that exhibits high catalytic activity for Lewis acid catalyzed reactions. Most importantly, this work pro-vides fresh insights into the connection between linker apportionment and vacancy distribution, which may shed light on prob-ing the disordered linker apportionment in multivariate systems, a long-standing challenge in the study of MTV-MOFs.

  8. Creating a Discovery Platform for Confined-Space Chemistry and Materials: Metal-Organic Frameworks.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Greathouse, Jeffery A.; Simmons, Blake

    2008-09-01

    Metal organic frameworks (MOF) are a recently discovered class of nanoporous, defect-free crystalline materials that enable rational design and exploration of porous materials at the molecular level. MOFs have tunable monolithic pore sizes and cavity environments due to their crystalline nature, yielding properties exceeding those of most other porous materials. These include: the lowest known density (91% free space); highest surface area; tunable photoluminescence; selective molecular adsorption; and methane sorption rivaling gas cylinders. These properties are achieved by coupling inorganic metal complexes such as ZnO4 with tunable organic ligands that serve as struts, allowing facile manipulation of pore size and surface area through reactant selection. MOFs thus provide a discovery platform for generating both new understanding of chemistry in confined spaces and novel sensors and devices based on their unique properties. At the outset of this project in FY06, virtually nothing was known about how to couple MOFs to substrates and the science of MOF properties and how to tune them was in its infancy. An integrated approach was needed to establish the required knowledge base for nanoscale design and develop methodologies integrate MOFs with other materials. This report summarizes the key accomplishments of this project, which include creation of a new class of radiation detection materials based on MOFs, luminescent MOFs for chemical detection, use of MOFs as templates to create nanoparticles of hydrogen storage materials, MOF coatings for stress-based chemical detection using microcantilevers, and "flexible" force fields that account for structural changes in MOFs that occur upon molecular adsorption/desorption. Eight journal articles, twenty presentations at scientific conferences, and two patent applications resulted from the work. The project created a basis for continuing development of MOFs for many Sandia applications and succeeded in securing $2.75 M in

  9. Mesoporous Fluorinated Metal-Organic Frameworks with Exceptional Adsorption of Fluorocarbons and CFCs.

    Science.gov (United States)

    Chen, Teng-Hao; Popov, Ilya; Kaveevivitchai, Watchareeya; Chuang, Yu-Chun; Chen, Yu-Sheng; Jacobson, Allan J; Miljanić, Ognjen Š

    2015-11-16

    Two mesoporous fluorinated metal-organic frameworks (MOFs) were synthesized from extensively fluorinated tritopic carboxylate- and tetrazolate-based ligands. The tetrazolate-based framework MOFF-5 has an accessible surface area of 2445 m(2) g(-1), the highest among fluorinated MOFs. Crystals of MOFF-5 adsorb hydrocarbons, fluorocarbons, and chlorofluorocarbons (CFCs)-the latter two being ozone-depleting substances and potent greenhouse species-with weight capacities of up to 225%. The material exhibits an apparent preference for the adsorption of non-spherical molecules, binding unusually low amounts of both tetrafluoromethane and sulfur hexafluoride. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Chiral metal-organic frameworks bearing free carboxylic acids for organocatalyst encapsulation.

    Science.gov (United States)

    Liu, Yan; Xi, Xiaobing; Ye, Chengcheng; Gong, Tengfei; Yang, Zhiwei; Cui, Yong

    2014-12-08

    Two chiral carboxylic acid functionalized micro- and mesoporous metal-organic frameworks (MOFs) are constructed by the stepwise assembly of triple-stranded heptametallic helicates with six carboxylic acid groups. The mesoporous MOF with permanent porosity functions as a host for encapsulation of an enantiopure organic amine catalyst by combining carboxylic acids and chiral amines in situ through acid-base interactions. The organocatalyst-loaded framework is shown to be an efficient and recyclable heterogeneous catalyst for the asymmetric direct aldol reactions with significantly enhanced stereoselectivity in relative to the homogeneous organocatalyst. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Metal-Organic Nanosheets Formed via Defect-Mediated Transformation of a Hafnium Metal-Organic Framework.

    Science.gov (United States)

    Cliffe, Matthew J; Castillo-Martínez, Elizabeth; Wu, Yue; Lee, Jeongjae; Forse, Alexander C; Firth, Francesca C N; Moghadam, Peyman Z; Fairen-Jimenez, David; Gaultois, Michael W; Hill, Joshua A; Magdysyuk, Oxana V; Slater, Ben; Goodwin, Andrew L; Grey, Clare P

    2017-04-19

    We report a hafnium-containing MOF, hcp UiO-67(Hf), which is a ligand-deficient layered analogue of the face-centered cubic fcu UiO-67(Hf). hcp UiO-67 accommodates its lower ligand:metal ratio compared to fcu UiO-67 through a new structural mechanism: the formation of a condensed "double cluster" (Hf 12 O 8 (OH) 14 ), analogous to the condensation of coordination polyhedra in oxide frameworks. In oxide frameworks, variable stoichiometry can lead to more complex defect structures, e.g., crystallographic shear planes or modules with differing compositions, which can be the source of further chemical reactivity; likewise, the layered hcp UiO-67 can react further to reversibly form a two-dimensional metal-organic framework, hxl UiO-67. Both three-dimensional hcp UiO-67 and two-dimensional hxl UiO-67 can be delaminated to form metal-organic nanosheets. Delamination of hcp UiO-67 occurs through the cleavage of strong hafnium-carboxylate bonds and is effected under mild conditions, suggesting that defect-ordered MOFs could be a productive route to porous two-dimensional materials.

  12. Recent advances in metal-organic frameworks and covalent organic frameworks for sample preparation and chromatographic analysis.

    Science.gov (United States)

    Wang, Xuan; Ye, Nengsheng

    2017-12-01

    In the field of analytical chemistry, sample preparation and chromatographic separation are two core procedures. The means by which to improve the sensitivity, selectivity and detection limit of a method have become a topic of great interest. Recently, porous organic frameworks, such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), have been widely used in this research area because of their special features, and different methods have been developed. This review summarizes the applications of MOFs and COFs in sample preparation and chromatographic stationary phases. The MOF- or COF-based solid-phase extraction (SPE), solid-phase microextraction (SPME), gas chromatography (GC), high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC) methods are described. The excellent properties of MOFs and COFs have resulted in intense interest in exploring their performance and mechanisms for sample preparation and chromatographic separation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Ultrafast rotation in an amphidynamic crystalline metal organic framework.

    Science.gov (United States)

    Vogelsberg, Cortnie S; Uribe-Romo, Fernando J; Lipton, Andrew S; Yang, Song; Houk, K N; Brown, Stuart; Garcia-Garibay, Miguel A

    2017-12-26

    Amphidynamic crystals are an emergent class of condensed phase matter designed with a combination of lattice-forming elements linked to components that display engineered dynamics in the solid state. Here, we address the design of a crystalline array of molecular rotors with inertial diffusional rotation at the nanoscale, characterized by the absence of steric or electronic barriers. We solved this challenge with 1,4-bicyclo[2.2.2]octane dicarboxylic acid (BODCA)-MOF, a metal-organic framework (MOF) built with a high-symmetry bicyclo[2.2.2]octane dicarboxylate linker in a Zn 4 O cubic lattice. Using spin-lattice relaxation 1 H solid-state NMR at 29.49 and 13.87 MHz in the temperature range of 2.3-80 K, we showed that internal rotation occurs in a potential with energy barriers of 0.185 kcal mol -1 These results were confirmed with 2 H solid-state NMR line-shape analysis and spin-lattice relaxation at 76.78 MHz obtained between 6 and 298 K, which, combined with molecular dynamics simulations, indicate that inertial diffusional rotation is characterized by a broad range of angular displacements with no residence time at any given site. The ambient temperature rotation of the bicyclo[2.2.2]octane (BCO) group in BODCA-MOF constitutes an example where engineered rotational dynamics in the solid state are as fast as they would be in a high-density gas or in a low-density liquid phase.

  14. Ultrafast rotation in an amphidynamic crystalline metal organic framework

    Energy Technology Data Exchange (ETDEWEB)

    Vogelsberg, Cortnie S.; Uribe-Romo, Fernando J.; Lipton, Andrew S.; Yang, Song; Houk, K. N.; Brown, Stuart; Garcia-Garibay, Miguel A.

    2017-12-11

    Amphidynamic crystals are an emergent class of condensed phase matter designed with a combination of lattice-forming elements linked to components that display engineered dynamics in the solid state. Here, we address the design of a crystalline array of molecular rotors with inertial diffusional rotation at the nanoscale, characterized by the absence of steric or electronic barriers. We solved this challenge with 1,4-bicyclo[2.2.2]octane dicarboxylic acid (BODCA)-MOF, a metal-organic framework (MOF) built with a high-symmetry bicyclo[2.2.2]octane dicarboxylate linker in a Zn4O cubic lattice. Using spin-lattice relaxation 1H solid-state NMR at 29.49 and 13.87 MHz in the temperature range of 2.3–80 K, we showed that internal rotation occurs in a potential with energy barriers of 0.185 kcal mol-1. These results were confirmed with 2H solid-state NMR line-shape analysis and spin-lattice relaxation at 76.78 MHz obtained between 6 and 298 K, which, combined with molecular dynamics simulations, indicate that inertial diffusional rotation is characterized by a broad range of angular displacements with no residence time at any given site. The ambient temperature rotation of the bicyclo[2.2.2]octane (BCO) group in BODCA-MOF constitutes an example where engineered rotational dynamics in the solid state are as fast as they would be in a high-density gas or in a low-density liquid phase.

  15. Neutron powder diffraction of metal-organic frameworks for hydrogen storage

    International Nuclear Information System (INIS)

    Brown, Craig M.; Liu, Yun; Neumann, Dan A.

    2008-01-01

    We review recent structural studies that we have undertaken aimed at elucidating the fundamental properties of metal-organic framework materials and their interactions with hydrogen. We have shown that exposing coordinatively unsaturated metal centers can greatly enhance the hydrogen binding energy and that they result in a significant increase of the surface packing density of adsorbed hydrogen molecules on materials surface. We will review some of the structural aspects of these materials, especially the adsorbed hydrogen molecule surface packing density in one type of metal-organic framework, MOF-74, which can be packed even denser than that in solid hydrogen. (author)

  16. A sol-gel monolithic metal-organic framework with enhanced methane uptake

    Science.gov (United States)

    Tian, Tian; Zeng, Zhixin; Vulpe, Diana; Casco, Mirian E.; Divitini, Giorgio; Midgley, Paul A.; Silvestre-Albero, Joaquin; Tan, Jin-Chong; Moghadam, Peyman Z.; Fairen-Jimenez, David

    2018-02-01

    A critical bottleneck for the use of natural gas as a transportation fuel has been the development of materials capable of storing it in a sufficiently compact form at ambient temperature. Here we report the synthesis of a porous monolithic metal-organic framework (MOF), which after successful packing and densification reaches 259 cm3 (STP) cm-3 capacity. This is the highest value reported to date for conformed shape porous solids, and represents a greater than 50% improvement over any previously reported experimental value. Nanoindentation tests on the monolithic MOF showed robust mechanical properties, with hardness at least 130% greater than that previously measured in its conventional MOF counterparts. Our findings represent a substantial step in the application of mechanically robust conformed and densified MOFs for high volumetric energy storage and other industrial applications.

  17. A sol-gel monolithic metal-organic framework with enhanced methane uptake.

    Science.gov (United States)

    Tian, Tian; Zeng, Zhixin; Vulpe, Diana; Casco, Mirian E; Divitini, Giorgio; Midgley, Paul A; Silvestre-Albero, Joaquin; Tan, Jin-Chong; Moghadam, Peyman Z; Fairen-Jimenez, David

    2018-02-01

    A critical bottleneck for the use of natural gas as a transportation fuel has been the development of materials capable of storing it in a sufficiently compact form at ambient temperature. Here we report the synthesis of a porous monolithic metal-organic framework (MOF), which after successful packing and densification reaches 259 cm 3 (STP) cm -3 capacity. This is the highest value reported to date for conformed shape porous solids, and represents a greater than 50% improvement over any previously reported experimental value. Nanoindentation tests on the monolithic MOF showed robust mechanical properties, with hardness at least 130% greater than that previously measured in its conventional MOF counterparts. Our findings represent a substantial step in the application of mechanically robust conformed and densified MOFs for high volumetric energy storage and other industrial applications.

  18. Metal-organic framework based highly selective fluorescence turn-on probe for hydrogen sulphide

    Science.gov (United States)

    Nagarkar, Sanjog S.; Saha, Tanmoy; Desai, Aamod V.; Talukdar, Pinaki; Ghosh, Sujit K.

    2014-11-01

    Hydrogen sulphide (H2S) is known to play a vital role in human physiology and pathology which stimulated interest in understanding complex behaviour of H2S. Discerning the pathways of H2S production and its mode of action is still a challenge owing to its volatile and reactive nature. Herein we report azide functionalized metal-organic framework (MOF) as a selective turn-on fluorescent probe for H2S detection. The MOF shows highly selective and fast response towards H2S even in presence of other relevant biomolecules. Low cytotoxicity and H2S detection in live cells, demonstrate the potential of MOF towards monitoring H2S chemistry in biological system. To the best of our knowledge this is the first example of MOF that exhibit fast and highly selective fluorescence turn-on response towards H2S under physiological conditions.

  19. Computational design of metal-organic frameworks with paddlewheel-type secondary building units

    Science.gov (United States)

    Schwingenschlogl, Udo; Peskov, Maxim V.; Masghouni, Nejib

    We employ the TOPOS package to study 697 coordination polymers containing paddlewheel-type secondary building units. The underlying nets are analyzed and 3 novel nets are chosen as potential topologies for paddlewheel-type metal organic frameworks (MOFs). Dicarboxylate linkers are used to build basic structures for novel isoreticular MOF series, aiming at relatively compact structures with a low number of atoms per unit cell. The structures are optimized using density functional theory. Afterwards the Grand Canonical Monte Carlo approach is employed to generate adsorption isotherms for CO2, CO, and CH4 molecules. We utilize the universal forcefield for simulating the interaction between the molecules and hosting MOF. The diffusion behavior of the molecules inside the MOFs is analyzed by molecular dynamics simulations.

  20. Direct Synthesis of 7 nm Thick Zinc(II)-Benzimidazole-Acetate Metal-Organic Framework Nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Feng; Kumar, Prashant; Xu, Wenqian; Mkhoyan, K. Andre; Tsapatsis, Michael

    2018-01-09

    Two-dimensional metal-organic frameworks (MOFs) are promising candidates for high performance gas sepa-ration membranes. Currently, MOF nanosheets are mostly fabricated through delamination of layered MOFs, which often re-sults in a low yield of intact free-standing nanosheets. In this work, we present a direct synthesis method for zinc(II)-benzimidazole-acetate (Zn(Bim)OAc) MOF nanosheets. The obtained nanosheets have a lateral dimension of 600 nm when synthesized at room temperature. By adjusting the synthesis temperature, the morphology of obtained nanosheets can be readily tuned from nanosheets to nanobelts. A thickness of 7 nm is determined for Zn(Bim)OAc using high-angle annular dark-field scanning transmission electron microscopy, which makes these nanosheets promising building blocks of gas sepa-ration membranes.

  1. Luminescent metal-organic frameworks for chemical sensing and explosive detection.

    Science.gov (United States)

    Hu, Zhichao; Deibert, Benjamin J; Li, Jing

    2014-08-21

    Metal-organic frameworks (MOFs) are a unique class of crystalline solids comprised of metal cations (or metal clusters) and organic ligands that have shown promise for a wide variety of applications. Over the past 15 years, research and development of these materials have become one of the most intensely and extensively pursued areas. A very interesting and well-investigated topic is their optical emission properties and related applications. Several reviews have provided a comprehensive overview covering many aspects of the subject up to 2011. This review intends to provide an update of work published since then and focuses on the photoluminescence (PL) properties of MOFs and their possible utility in chemical and biological sensing and detection. The spectrum of this review includes the origin of luminescence in MOFs, the advantages of luminescent MOF (LMOF) based sensors, general strategies in designing sensory materials, and examples of various applications in sensing and detection.

  2. Metal-Organic Framework Thin Films as Stationary Phases in Microfabricated Gas-Chromatography Columns.

    Energy Technology Data Exchange (ETDEWEB)

    Read, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sillerud, Colin Halliday [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    The overarching goal of this project is to integrate Sandia's microfabricated gas-chromatography ( GC) columns with a stationary phase material that is capable of retaining high-volatility chemicals and permanent gases. The successful integration of such a material with GCs would dramatically expand the repertoire of detectable compounds for Sandia's various microanalysis systems. One such promising class of candidate materials is metal-organic frameworks (MOFs). In this report we detail our methods for controlled deposition of HKUST-1 MOF stationary phases within GC columns. We demonstrate: the chromatographic separation of natural gas; a method for determining MOF film thickness from chromatography alone; and the first-reported GC x GC separation of natural gas -- in general -- let alone for two disparate MOF stationary phases. In addition we determine the fundamental thermodynamic constant for mass sorption, the partition coefficient, for HKUST-1 and several light hydrocarbons and select toxic industrial chemicals.

  3. A novel series of isoreticular metal organic frameworks: Realizing metastable structures by liquid phase epitaxy

    KAUST Repository

    Liu, Jinxuan

    2012-12-04

    A novel class of metal organic frameworks (MOFs) has been synthesized from Cu-acetate and dicarboxylic acids using liquid phase epitaxy. The SURMOF-2 isoreticular series exhibits P4 symmetry, for the longest linker a channel-size of 3 3 nm2 is obtained, one of the largest values reported for any MOF so far. High quality, ab-initio electronic structure calculations confirm the stability of a regular packing of (Cu++) 2-carboxylate paddle-wheel planes with P4 symmetry and reveal, that the SURMOF-2 structures are in fact metastable, with a fairly large activation barrier for the transition to the bulk MOF-2 structures exhibiting a lower, twofold (P2 or C2) symmetry. The theoretical calculations also allow identifying the mechanism for the low-temperature epitaxial growth process and to explain, why a synthesis of this highly interesting, new class of high-symmetry, metastable MOFs is not possible using the conventional solvothermal process.

  4. Hydroisomerization of n-Hexane Using Acidified Metal-Organic Framework and Platinum Nanoparticles.

    Science.gov (United States)

    Sabyrov, Kairat; Jiang, Juncong; Yaghi, Omar M; Somorjai, Gabor A

    2017-09-13

    Exceptionally high surface area and ordered nanopores of a metal-organic framework (MOF) are exploited to encapsulate and homogeneously disperse a considerable amount of phosphotungstic acid (PTA). When combined with platinum nanoparticles positioned on the external surface of the MOF, the construct shows a high catalytic activity for hydroisomerization of n-hexane, a reaction requiring hydrogenation/dehydrogenation and moderate to strong Brønsted acid sites. Characterization of the catalytic activity and acidic sites as a function of PTA loading demonstrates that both the concentration and strength of acidic sites are highest for the catalyst with the largest amount of PTA. The MOF construct containing 60% PTA by weight produces isoalkanes with 100% selectivity and 9-fold increased mass activity as compared to a more traditional aluminosilicate catalyst, further demonstrating the capacity of the MOF to contain a high concentration of active sites necessary for the isomerization reaction.

  5. Metal-Organic Framework of Lanthanoid Dinuclear Clusters Undergoes Slow Magnetic Relaxation

    Directory of Open Access Journals (Sweden)

    Hikaru Iwami

    2017-01-01

    Full Text Available Lanthanoid metal-organic frameworks (Ln-MOFs can adopt a variety of new structures due to the large coordination numbers of Ln metal ions, and Ln-MOFs are expected to show new luminescence and magnetic properties due to the localized f electrons. In particular, some Ln metal ions, such as Dy(III and Tb(III ions, work as isolated quantum magnets when they have magnetic anisotropy. In this work, using 4,4′,4″-s-triazine-2,4,6-triyl-tribenzoic acid (H3TATB as a ligand, two new Ln-MOFs, [Dy(TATB(DMF2] (1 and [Tb(TATB(DMF2] (2, were obtained. The Ln-MOFs contain Ln dinuclear clusters as secondary building units, and 1 underwent slow magnetic relaxation similar to single-molecule magnets.

  6. Remarkable CO2/CH4 selectivity and CO2 adsorption capacity exhibited by polyamine-decorated metal-organic framework adsorbents.

    Science.gov (United States)

    Yan, Qiuju; Lin, Yichao; Kong, Chunlong; Chen, Liang

    2013-08-07

    Solid porous dual amine-decorated metal-organic framework (MOF) adsorbents with tunable porosity have been prepared. The adsorbents exhibit remarkable CO2/CH4 selectivity and CO2 adsorption capacity at low pressures.

  7. Reversible Redox Activity in Multicomponent Metal-Organic Frameworks Constructed from Trinuclear Copper Pyrazolate Building Blocks.

    Science.gov (United States)

    Tu, Binbin; Pang, Qingqing; Xu, Huoshu; Li, Xiaomin; Wang, Yulin; Ma, Zhen; Weng, Linhong; Li, Qiaowei

    2017-06-14

    Inorganic functionalization of metal-organic frameworks (MOFs), such as incorporation of multiple inorganic building blocks with distinct metals into one structure and further modulation of the metal charges, endows the porous materials with significant properties toward their applications in catalysis. In this work, by an exploration of the role of 4-pyrazolecarboxylic acid (H 2 PyC) in the formation of trinuclear copper pyrazolate as a metalloligand in situ, four new MOFs with multiple components in order were constructed through one-pot synthesis. This metalloligand strategy provides multicomponent MOFs with new topologies (tub for FDM-4 and tap for FDM-5) and is also compatible with a second organic linker for cooperative construction of complex MOFs (1,4-benzenedicarboxylic acid for FDM-6 and 2,6-naphthalenedicarboxylic acid for FDM-7). The component multiplicity of these MOFs originates from PyC's ability to separate Cu and Zn on the basis of their differentiated binding affinities toward pyrazolate and carboxylate. These MOFs feature reversible and facile redox transformations between Cu I 3 (PyC) 3 and Cu II 3 (μ-OH)(PyC) 3 (OH) 3 without altering the connecting geometries of the units, thus further contributing to the significant catalytic activities in the oxidation of CO and aromatic alcohols and the decomposition of H 2 O 2 . This study on programming multiple inorganic components into one framework and modulating their electronic structures is an example of functionalizing the inorganic units of MOFs with a high degree of control.

  8. Signature of Metallic Behavior in the Metal-Organic Frameworks M3(hexaiminobenzene)2(M = Ni, Cu).

    Science.gov (United States)

    Dou, Jin-Hu; Sun, Lei; Ge, Yicong; Li, Wenbin; Hendon, Christopher H; Li, Ju; Gul, Sheraz; Yano, Junko; Stach, Eric A; Dincă, Mircea

    2017-10-04

    The two-dimensionally connected metal-organic frameworks (MOFs) Ni 3 (HIB) 2 and Cu 3 (HIB) 2 (HIB = hexaiminobenzene) are bulk electrical conductors and exhibit ultraviolet-photoelectron spectroscopy (UPS) signatures expected of metallic solids. Electronic band structure calculations confirm that in both materials the Fermi energy lies in a partially filled delocalized band. Together with additional structural characterization and microscopy data, these results represent the first report of metallic behavior and permanent porosity coexisting within a metal-organic framework.

  9. Effects of ultrasound on properties of ni-metal organic framework nanostructures

    Directory of Open Access Journals (Sweden)

    Abbas Pardakhty

    2016-10-01

    Full Text Available Objective(s: According to the unique properties of magnetic nanoparticles, Nickel Metal-Organic Frameworks (MOF was synthesized successfully by ultrasound irradiation. Metal-organic frameworks (MOFs are organic–inorganic hybrid extended networks that are constructed via covalent linkages between metal ions/metal clusters and organic ligands called a linker. Materials and Methods: The nanoparticles were synthesized by Ultrasound  Method Under a synthesis conditions, All chemicals were used as received without further purification. Scanning electron microscopy (SEM images were obtained on LEO- 1455VP equipped with an energy dispersive X-ray spectroscopy at university of Kashan in Iran. Transition electron microscopy (TEM images were obtained on EM208 Philips transmission electron microscope with an accelerating voltage of 200 kV. Results: Results showed that Ni-MOF synthesized by this method, had smaller particle size distribution and It was found that the different kinds of ligand leads to preparation products with different morphologies and textural properties. Moreover, ultrasound irradiation method has significant effect on microstructures of as-synthesized MOFs and can improve their textural properties compared to method without using hydrothermal route.The XRD patterns of the samples obtained from ultrasound irradiation was well matched with that of as-prepared Ni-MOF by solvothermal method. Conclusion: This rapid method of ultrasonic radiation as compared to the classical solvothermal synthesis, showed promising results in terms of size distribution, surface area, pore diameter and pore volume.

  10. Nanosizing a Metal-Organic Framework Enzyme Carrier for Accelerating Nerve Agent Hydrolysis.

    Science.gov (United States)

    Li, Peng; Moon, Su-Young; Guelta, Mark A; Lin, Lu; Gómez-Gualdrón, Diego A; Snurr, Randall Q; Harvey, Steven P; Hupp, Joseph T; Farha, Omar K

    2016-10-05

    We report the synthesis and characterization of a water-stable zirconium metal-organic framework (MOF), NU-1003, featuring the largest mesoporous aperture known for a zirconium MOF. This material has been used to immobilize the nerve agent hydrolyzing enzyme, organophosphorus acid anhydrolase (OPAA). The catalytic efficiency of immobilized OPAA in nanosized NU-1003 is significantly increased compared to that of OPAA immobilized in microsized NU-1003 and even exceeds that of the free OPAA enzyme. This paper highlights a method for rapid and highly efficient hydrolysis of nerve agents using nanosized enzyme carriers.

  11. Metal-organic frameworks and their applications in catalysis; Redes metalorganicas e suas aplicacoes em catalise

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Andre Luis Dantas, E-mail: aldramos@ufs.br [Universidade Federal de Sergipe (UFSE), Sao Cristovao, SE (Brazil). Departamento de Engenharia Quimica; Tanase, Stefania; Rothenberg, Gadi [Van' t Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam (Netherlands)

    2014-07-01

    Metal-organic frameworks (MOFs) form a new class of materials with well-defined yet tunable properties. These are crystalline, highly porous and exhibit strong metal-ligand interactions. Importantly, their physical and chemical properties, including pore size, pore structure, acidity, and magnetic and optical characteristics, can be tailored by choosing the appropriate ligands and metal precursors. Here we review the key aspects of synthesis and characterization of MOFs, focusing on lanthanide-based and vanadium-based materials. We also outline some of their applications in catalysis and materials science. (author)

  12. A highly stable zeotype mesoporous zirconium metal-organic framework with ultralarge pores.

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Dawei; Wang, Kecheng; Su, Jie; Liu, Tian-Fu; Park, Jihye; Wei, Zhangwen; Bosch, Mathieu; Yakovenko, Andrey; Zou, Xiaodong; Zhou, Hong-Cai

    2015-01-02

    Through topological rationalization, a zeotype mesoporous Zr-containing metal-organic framework (MOF), namely PCN-777, has been designed and synthesized. PCN-777 exhibits the largest cage size of 3.8nm and the highest pore volume of 2.8cm(3)g(-1) among reported Zr-MOFs. Moreover, PCN-777 shows excellent stability in aqueous environments, which makes it an ideal candidate as a support to incorporate different functional moieties. Through facile internal surface modification, the interaction between PCN-777 and different guests can be varied to realize efficient immobilization

  13. A Hafnium-Based Metal-Organic Framework as a Nature-Inspired Tandem Reaction Catalyst.

    Science.gov (United States)

    Beyzavi, M Hassan; Vermeulen, Nicolaas A; Howarth, Ashlee J; Tussupbayev, Samat; League, Aaron B; Schweitzer, Neil M; Gallagher, James R; Platero-Prats, Ana E; Hafezi, Nema; Sarjeant, Amy A; Miller, Jeffrey T; Chapman, Karena W; Stoddart, J Fraser; Cramer, Christopher J; Hupp, Joseph T; Farha, Omar K

    2015-10-28

    Tandem catalytic systems, often inspired by biological systems, offer many advantages in the formation of highly functionalized small molecules. Herein, a new metal-organic framework (MOF) with porphyrinic struts and Hf6 nodes is reported. This MOF demonstrates catalytic efficacy in the tandem oxidation and functionalization of styrene utilizing molecular oxygen as a terminal oxidant. The product, a protected 1,2-aminoalcohol, is formed selectively and with high efficiency using this recyclable heterogeneous catalyst. Significantly, the unusual regioselective transformation occurs only when an Fe-decorated Hf6 node and the Fe-porphyrin strut work in concert. This report is an example of concurrent orthogonal tandem catalysis.

  14. Thermodynamics of Pore Filling Metal Clusters in Metal Organic Frameworks: Pd in UiO-66

    DEFF Research Database (Denmark)

    Vilhelmsen, Lasse; Sholl, David S.

    2012-01-01

    Metal organic frameworks (MOFs) have experimentally been demonstrated to be capable of supporting isolated transition-metal clusters, but the stability of these clusters with respect to aggregation is unclear. In this letter we use a genetic algorithm together with density functional theory...... calculations to predict the structure of Pd clusters in UiO-66. The cluster sizes examined are far larger than those in any previous modeling studies of metal clusters in MOFs and allow us to test the hypothesis that the physically separated cavities in UiO-66 could stabilize isolated Pd clusters. Our...

  15. Design, Synthesis and Characterization of Functional Metal-Organic Framework Materials

    KAUST Repository

    Alamer, Badriah

    2015-06-01

    Over the past few decades, vast majority of industrial and academic research throughout the world has witnessed the emergence of materials that can serve as ideal candidates for potential utility in desired applications, and these materials are known as Metal Organic Framework (MOFs). This exceptional new family of porous materials is fabricated by linkage of metal ions or clusters and organic linkers via strong bonds. MOFs have been awarded with remarkable interest and widely studied due to their inherent structural methodology (e.g. use of various metals, expanded library of organic building blocks with different geometry and functionality particularly frameworks designed from carboxylate organic linkers) and unquestionably unique structural and chemical features for many practical applications. (i.e. gas storage/separation, catalysis, drug delivery etc). Simply, metal organic frameworks epitomize the beauty of porous chemical structures. From a design perspective, the introduction of the Molecular Building Block (MBB) approach is actively being pursued pathway by researchers toward the construction of MOFs by employing inorganic building blocks and organic linkers and taking advantage of not only their multiple coordination modes and geometries but also the way in which they are reticulated to generate final framework. In this thesis, research studies will be directed toward (i) the investigation of the relationship between experimental parameters and synthesis of well-known fcu –MOF, (ii) rational design and synthesis of new rare earth (RE) based MOFs, (ii) isoreticular materials based on particular MBB ([M3O(RCO2)6]), M= p-and d-block metals, and (iv) zeolite- like metal organic framework assembled from single-metal ion based MBB ([MN2(CO2)4]) via 2-, 3-,and 4-connected organic linkers. Consequently, the porosity, chemical and thermal stability, and gas sorption properties will be evaluated and detailed.

  16. Research Update: Mechanical properties of metal-organic frameworks – Influence of structure and chemical bonding

    Directory of Open Access Journals (Sweden)

    Wei Li

    2014-12-01

    Full Text Available Metal-organic frameworks (MOFs, a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

  17. High-Throughput Molecular Simulations of Metal Organic Frameworks for CO2 Separation: Opportunities and Challenges

    Directory of Open Access Journals (Sweden)

    Ilknur Erucar

    2018-02-01

    Full Text Available Metal organic frameworks (MOFs have emerged as great alternatives to traditional nanoporous materials for CO2 separation applications. MOFs are porous materials that are formed by self-assembly of transition metals and organic ligands. The most important advantage of MOFs over well-known porous materials is the possibility to generate multiple materials with varying structural properties and chemical functionalities by changing the combination of metal centers and organic linkers during the synthesis. This leads to a large diversity of materials with various pore sizes and shapes that can be efficiently used for CO2 separations. Since the number of synthesized MOFs has already reached to several thousand, experimental investigation of each MOF at the lab-scale is not practical. High-throughput computational screening of MOFs is a great opportunity to identify the best materials for CO2 separation and to gain molecular-level insights into the structure–performance relationships. This type of knowledge can be used to design new materials with the desired structural features that can lead to extraordinarily high CO2 selectivities. In this mini-review, we focused on developments in high-throughput molecular simulations of MOFs for CO2 separations. After reviewing the current studies on this topic, we discussed the opportunities and challenges in the field and addressed the potential future developments.

  18. Ionic Liquid/Metal-Organic Framework Composites: From Synthesis to Applications.

    Science.gov (United States)

    Kinik, Fatma Pelin; Uzun, Alper; Keskin, Seda

    2017-07-21

    Metal-organic frameworks (MOFs) have been widely studied for different applications owing to their fascinating properties such as large surface areas, high porosities, tunable pore sizes, and acceptable thermal and chemical stabilities. Ionic liquids (ILs) have been recently incorporated into the pores of MOFs as cavity occupants to change the physicochemical properties and gas affinities of MOFs. Several recent studies have shown that IL/MOF composites show superior performances compared with pristine MOFs in various fields, such as gas storage, adsorption and membrane-based gas separation, catalysis, and ionic conductivity. In this review, we address the recent advances in syntheses of IL/MOF composites and provide a comprehensive overview of their applications. Opportunities and challenges of using IL/MOF composites in many applications are reviewed and the requirements for the utilization of these composite materials in real industrial processes are discussed to define the future directions in this field. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Proton Conductivity of Proton Exchange Membrane Synergistically Promoted by Different Functionalized Metal-Organic Frameworks.

    Science.gov (United States)

    Rao, Zhuang; Tang, Beibei; Wu, Peiyi

    2017-07-12

    In this study, two functionalized metal-organic frameworks (MOFs), UiO-66-SO 3 H and UiO-66-NH 2 , were synthesized. Then, different composite proton exchange membranes (PEMs) were prepared by single doping and codoping of these two MOFs, respectively. It was found that codoping of these two MOFs with suitable sizes was more conducive to the proton conductivity enhancement of the composite PEM. A synergistic effect between these two MOFs led to the the formation of more consecutive hydration channels in the composite PEM. It further greatly promoted the proton conductivity of the composite PEM. The proton conductivity of the codoped PEM reached up to 0.256 S/cm under 90 °C, 95% RH, which was ∼1.17 times higher than that of the recast Nafion (0.118 S/cm). Besides, the methanol permeability of the codoped PEM was prominently decreased owing to the methanol trapping effect of the pores of these two MOFs. Meanwhile, the high water and thermal stabilities of these two MOFs were beneficial to the high proton conductivity stability of the codoped PEM under high humidity and high temperature. The proton conductivity of the codoped PEM was almost unchanged throughout 3000 min of testing under 90 °C, 95% RH. This work provides a valuable reference for designing different functionalized MOFs to synergistically promote the proton conductivities of PEMs.

  20. An unconventional rapid synthesis of high performance metal-organic framework membranes.

    Science.gov (United States)

    Shah, Miral N; Gonzalez, Mariel A; McCarthy, Michael C; Jeong, Hae-Kwon

    2013-06-25

    Metal-organic frameworks (MOFs) are attractive for gas separation membrane applications due to their microporous channels with tunable pore shape, size, and functionality. Conventional MOF membrane fabrication techniques, namely in situ and secondary growth, pose challenges for their wider commercial applications. These challenges include reproducility, scalability, and high manufacturing cost. Recognizing that the coordination chemistry of MOFs is fundamentally different from the covalent chemistry of zeolites, we developed a radically different strategy for MOF membrane synthesis. Using this new technique, we were able to produce continuous well-intergrown membranes of prototypical MOFs, HKUST-1 and ZIF-8, in a relatively short period of time (tens of min). With a minimal consumption of precursors and a greatly simplified synthesis protocol, our new technique provides potential for a continuous, scalable, reproducible, and easily commercializable route for the rapid synthesis of MOF membranes. RTD-prepared MOF membranes show greatly improved gas separation performances as compared to those prepared by conventional solvothermal methods, indicating improved membrane microstructure.

  1. Defect-Controlled Preparation of UiO-66 Metal-Organic Framework Thin Films with Molecular Sieving Capability.

    Science.gov (United States)

    Zhang, Caiqin; Zhao, Yajing; Li, Yali; Zhang, Xuetong; Chi, Lifeng; Lu, Guang

    2016-01-01

    Metal-organic framework (MOF) UiO-66 thin films are solvothermally grown on conducting substrates. The as-synthesized MOF thin films are subsequently dried by a supercritical process or treated with polydimethylsiloxane (PDMS). The obtained UiO-66 thin films show excellent molecular sieving capability as confirmed by the electrochemical studies for redox-active species with different sizes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Electrosynthesis of Metal-Organic Frameworks (MOFs)Based on Nickel(II) and Benzene 1,3,5-Tri Carboxylic Acid (H3BTC): An Optimization Reaction Condition

    Science.gov (United States)

    Lestari, W. W.; Winarni, I. D.; Rahmawati, F.

    2017-02-01

    Electrosynthesis of metal-organic frameworks based on nickel(II) and benzen 1,3,5-tricarboxylic acid (H3BTC) to form [Ni3(BTC)2] has been conducted. This study aims to determine the optimum electro-synthetic conditions of [Ni3(BTC)2] by varying the solvents, electrolytes, as well as the voltages. The optimum condition was determined based on the percent yield of the product which upon washing and drying at room temperature showed pale green precipitate. The materialhas high crystallinityaccording to XRD analysis with the main peak observed at 2θ 19° and 28° and appropriate with [Ni3(BTC)2] pattern (CCDC No. 1274034). The refinement results using Le Bail methods revealed the Rp and Rwp values are 3.29% and 3.47%, respectively. The coordination between nickel(II) and carboxylate moeties of the linker has been characterized using FTIR and showed significant shift from 1723 cm-1 to 1608 cm-1. The compound has thermal stability up to 400 °C according to TG/DTA analysis. The SEM analysis confirmed that compound has morphology nanoplates shape with a thickness of 75 ± 0.023 nm. Another interesting feature of the obtained material is the occupancy of the reversible frameworks, which proved after methanol absorption. The optimum condition of the electro-synthesis of [Ni3(BTC)2] achieved in the methanol with TBATFB (0.1 M) as electrolyte, and the voltage of 15 V at room temperature with a yield of 99.99%.

  3. Synthesis, characterization and heterogeneous base catalysis of amino functionalized lanthanide metal-organic frameworks

    Science.gov (United States)

    Huang, Jinping; Li, Chunmei; Tao, Lingling; Zhu, Huilin; Hu, Gang

    2017-10-01

    Lanthanide metal-organic frameworks (Ln-MOFs) are featured by their tolerance to water and dense structure. In this work, an amine-functionalized Ln-MOF was facilely synthesized by coordination of terbium with 2-aminoterephthalic acid under the condition of microwave irradiation. The crystal structure was characterized by single crystal X-ray diffraction, FT-IR, Raman, TG-DTA and XPS analysis. The basic catalytic activity of the NH2-Tb-MOF was evaluated for Knoevenagel condensation and Henry reactions. Apart from the high activity and 100% selectivity to the condensation product, the NH2-Tb-MOF catalyst could be easily recycled and reused owing to the high stability of the MOF framework formed by coordination of Tb3+ with carboxylic groups. Remarkably, the NH2-Tb-MOF exhibited size-selective catalysis to substrates. For the small-sized reactants, it displayed comparable activity to the homogeneous catalyst of aniline owing to the high dispersion of NH2- active sites and the low diffusion limits. However, in the same reaction system, extremely poor activity in Knoevenagel condensation and Henry reaction for the bulky substrate 4-(tert-butyl) benzaldehyde was observed due to the both effects of substitute and inhibition of diffusion into the micropores. Crystal structure analysis provided a mechanistic evidence that the heterogeneous base catalysis arose from the amino groups densely distributed inside the micropores.

  4. Melt-quenched glasses of metal-organic frameworks

    DEFF Research Database (Denmark)

    Bennett, T.D.; Yue, Yuanzheng; Li, P.

    2016-01-01

    Crystalline solids dominate the field of metal−organic frameworks (MOFs), with access to the liquid and glass states of matter usually prohibited by relatively low temperatures of thermal decomposition. In this work, we give due consideration to framework chemistry and topology to expand...... of other MOFs. The glasses formed upon vitrification are chemically and structurally distinct from the three other existing categories of melt-quenched glasses (inorganic nonmetallic, organic, and metallic), and retain the basic metal−ligand connectivity of crystalline MOFs, which connects their mechanical...... the phenomenon of the melting of 3D MOFs, linking crystal chemistry to framework melting temperature and kinetic fragility of the glass-forming liquids. Here we show that melting temperatures can be lowered by altering the chemistry of the crystalline MOF state, which provides a route to facilitate the melting...

  5. Unconventional metal organic frameworks: porous cross-linked phosphonates.

    Science.gov (United States)

    Clearfield, Abraham

    2008-11-28

    The past decade has witnessed an exponential growth of metal organic framework compounds (MOFs). The defining character of these compounds is their porosity. However, in many cases no effort was made to show evidence that a stable porous structure has been achieved and that the pores may be accessed. In the present paper we describe recent work on porous pillared zirconium diphosphonates, and the newer and in many respects different characteristics of tin(iv) phosphonates. The Sn(IV) monophosphonates form spherical globules that exhibit very high surface areas. The surface area arises from their nano-sized particles that pack in a "house of cards" arrangement. Also, it is shown that the 1,4-monophenyldiphosphonic acid forms highly porous (250-400 m2 g(-1)) materials with Sn(IV) when prepared in alcohol-water media. This is not the case with analogous Zr(IV) compounds. The many variations in the syntheses of both the zirconium and tin aryl- and alkyldiphosphonate pillars and their combinations with spacers such as methyl- and monophenylphosphonic acid have created a variety of highly porous materials that are stable to 400 degrees C in air, highly stable in acid media, do not collapse when de-solvated, and can be post and presynthesis altered to include functional groups. Several new directions taken by other researchers are also described. However, it is emphasized in this presentation that the cross-linked compounds form particles that precipitate rapidly into nanoparticles that exhibit only short range order. Therefore, they differ from the more conventional MOFs in that they are not amenable to structure solution by X-ray or neutron diffraction techniques. Rather, they must be understood on the basis of modeling and indirect data from EM, NMR, and additional spectroscopic and textural studies.

  6. Toward Developing Made-to-Order Metal-Organic Frameworks: Design, Synthesis and Applications

    KAUST Repository

    Ashri, Lubna Y.

    2016-05-26

    Synthesis of materials with certain properties for targeted applications is an ongoing challenge in materials science. One of the most interesting classes of solid-state materials that have been recently introduced with the potential to address this is metal-organic frameworks (MOFs). MOFs chemistry offers a higher degree of control over materials to be synthesized utilizing various new design strategies, such as the molecular building blocks (MBBs) and the supermolecular building layers (SBLs) approaches. Depending on using predetermined building blocks, these strategies permit the synthesis of MOFs with targeted topologies and enable fine tuning of their properties. This study examines a number of aspects of the design and synthesis of MOFs while exploring their possible utilization in two diverse fields related to energy and pharmaceutical applications. Concerning MOFs design and synthesis, the work presented here explores the rational design of various MOFs with predicted topologies and tunable cavities constructed by pillaring pre-targeted 2-periodic SBLs using the ligand-to-axial and six-connected axial-to-axial pillaring strategies. The effect of expanding the confined spaces in prepared MOFs or modifying their functionalities, while preserving the underlying network topology, was investigated. Additionally, The MBBs approach was employed to discover new modular polynuclear rare earth (RE)-MBBs in the presence of different angular polytopic ligands containing carboxylate and nitrogen moieties with the aid of a modulator. The goal was to assess the diverse possible coordination modes and construct highly-connected nets for utility in the design of new MOFs and enhance the predictability of structural outcomes. The effect of adjusting ligands’ length-to-width ratio on the prepared MOFs was also evaluated. As a result, the reaction conditions amenable for reliable formation of the unprecedented octadecanuclear, octanuclear and double tetranuclear RE-MBBs were

  7. Pillared-Layer Metal-Organic Frameworks for Improved Lithium-Ion Storage Performance.

    Science.gov (United States)

    Gong, Teng; Lou, Xiaobing; Gao, En-Qing; Hu, Bingwen

    2017-07-05

    Recently, more and more metal-organic frameworks (MOFs) have been directly used as anodic materials in lithium-ion batteries, but judicious design or choice of MOFs is still challenging for lack of structural-property knowledge. In this article we propose a pillared-layer strategy to achieve improved Li-storage performance. Four Mn(II) and Co(II) MOFs with mixed azide and carboxylate ligands were studied to illustrate the strategy. In these 3D MOFs, layers (1, 3, and 4) or chains (2) with short bridges are linked by long organic spacers. All the MOFs show very high lithiation capacity (1170-1400 mA h g -1 at 100 mA g -1 ) in the first cycle owing to the rich insertion sites arising from the azide ion and the aromatic ligands. After the formation cycles, the reversible capacities of the anodes from 1, 3, and 4 are kept at a high level (580-595 mA h g -1 ) with good rate and cycling performance, while the anode from 2 undergoes a dramatic drop in capacity. All the MOFs lose the crystallinity after the first cycle. While the amorphization of the chain-based framework of 2 leads to major irreversible deposit of Li ions, the amorphous phases derived from the pillared-layer frameworks of 1, 3, and 4 still retain rich accessible space for reversible insertion and diffusion of active Li ions. Consistent with the analysis, electrochemical impedance spectra revealed that the pillared-layer MOFs led to significantly smaller charge-transfer resistances than 2. Soft X-ray absorption spectroscopy suggested that no metal conversion is involved in the lithiation process, consistent with the fact that the isomorphous Co(II) (3) and Mn(II) (4) MOFs are quite similar in anodic performance.

  8. Greening the Processes of Metal-Organic Framework Synthesis and their Use in Sustainable Catalysis.

    Science.gov (United States)

    Chen, Junying; Shen, Kui; Li, Yingwei

    2017-08-24

    Given the shortage of sustainable resources and the increasingly serious environmental issues in recent decades, the demand for clean technologies and sustainable feedstocks is of great interest to researchers worldwide. With regard to the fields of energy saving and environmental remediation, the key point is the development of efficient catalysts, not only in terms of facile synthesis methods, but also the benign utilization of such catalysts. This work reviews the use of metal-organic frameworks (MOFs) and MOF-based materials in these fields. The definition of MOFs and MOF-based materials will be primarily introduced followed by a brief description of the characterization and stability of MOF-related materials under the applied conditions. The greening of MOF synthesis processes will then be discussed and catalogued by benign solvents and conditions and green precursors of MOFs. Furthermore, their suitable application in sustainable catalysis will be summarized, focusing on several typical atom-economic reactions, such as the direct introduction of H 2 or O 2 and C-C bond formation. Approaches towards reducing CO 2 emission by MOF-based catalysts will be described with special emphasis on CO 2 fixation and CO 2 reduction. In addition, driven by the explosive growth of energy consumption in the last century, much research has gone into biomass, which represents a renewable alternative to fossil fuels and a sustainable carbon feedstock for chemical production. The advanced progress of biomass-related transformations is also illustrated herein. Fundamental insights into the nature of MOF-based materials as constitutionally easily recoverable heterogeneous catalysts and as supports for various active sites is thoroughly discussed. Finally, challenges facing the development of this field and the outlook for future research are presented. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Discovery and introduction of a (3,18)-connected net as an ideal blueprint for the design of metal-organic frameworks

    KAUST Repository

    Guillerm, Vincent

    2014-06-29

    Metal-organic frameworks (MOFs) are a promising class of porous materials because it is possible to mutually control their porous structure, composition and functionality. However, it is still a challenge to predict the network topology of such framework materials prior to their synthesis. Here we use a new rare earth (RE) nonanuclear carboxylate-based cluster as an 18-connected molecular building block to form a gea-MOF (gea-MOF-1) based on a (3,18)-connected net. We then utilized this gea net as a blueprint to design and assemble another MOF (gea-MOF-2). In gea-MOF-2, the 18-connected RE clusters are replaced by metal-organic polyhedra, peripherally functionalized so as to have the same connectivity as the RE clusters. These metal-organic polyhedra act as supermolecular building blocks when they form gea-MOF-2. The discovery of a (3,18)-connected MOF followed by deliberate transposition of its topology to a predesigned second MOF with a different chemical system validates the prospective rational design of MOFs. © 2014 Macmillan Publishers Limited. All rights reserved.

  10. Sensitive resonant gas sensor operating in air with metal organic frameworks coating

    KAUST Repository

    Jaber, Nizar

    2017-08-09

    We report a practical resonant gas sensor that is uniformly coated with metal organic frameworks (MOFs) and excited near the higher order modes for a higher attained sensitivity. The resonator is based on an electrostatically excited clamped-clamped microbeam. The microbeam is fabricated from a polyimide layer coated from the top with Cr/Au and from the bottom with Cr/Au/Cr layer. The geometry of the resonator is optimized to reduce the effect of the squeeze film damping, thereby allowing operation under atmospheric pressure. The electrostatic force electrode is designed to enhance the excitation of the second mode of vibration with the minimum power required. Significant frequency shift (kHz) is demonstrated for the first time upon water vapor, acetone, and ethanol exposure due to the MOFs functionalization and the higher order modes excitation. Also, the adsorption dynamics and MOF selectivity is investigated by studying the decaying time constants of the response upon gas exposure.

  11. A metal-organic framework-based splitter for separating propylene from propane

    KAUST Repository

    Cadiau, Amandine

    2016-07-07

    The chemical industry is dependent on the olefin/paraffin separation, which is mainly accomplished by using energy-intensive processes. We report the use of reticular chemistry for the fabrication of a chemically stable fluorinated metal-organic framework (MOF) material (NbOFFIVE-1-Ni, also referred to as KAUST-7). The bridging of Ni(II)-pyrazine square-grid layers with (NbOF5)2- pillars afforded the construction of a three-dimensional MOF, enclosing a periodic array of fluoride anions in contracted square-shaped channels. The judiciously selected bulkier (NbOF5)2- caused the looked-for hindrance of the previously free-rotating pyrazine moieties, delimiting the pore system and dictating the pore aperture size and its maximum opening. The restricted MOF window resulted in the selective molecular exclusion of propane from propylene at atmospheric pressure, as evidenced through multiple cyclic mixed-gas adsorption and calorimetric studies.

  12. A Simple Approach to Enhance the Water Stability of a Metal-Organic Framework.

    Science.gov (United States)

    Shih, Yung-Han; Kuo, Yu-Ching; Lirio, Stephen; Wang, Kun-Yun; Lin, Chia-Her; Huang, Hsi-Ya

    2017-01-01

    A facile method to improve the feasibility of water-unstable metal-organic frameworks in an aqueous environment has been developed that involves imbedding in a polymer monolith. The effect of compartment type during polymerization plays a significant role in maintaining the crystalline structure and thermal stability of the MOFs, which was confirmed by powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA), respectively. The MOF-polymer composite prepared in a narrow compartment (column, ID 0.8 mm) has better thermal and chemical stability than that prepared in a broad compartment (vial, ID 7 mm). The developed MOF-polymer composite was applied as an adsorbent in solid-phase microextraction of nine non-steroidal anti-inflammatory drugs (NSAIDs) and could be used for extraction more than 30 times, demonstrating that the proposed approach has potential for industrial applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks

    Science.gov (United States)

    Kim, Hyunho; Cho, H. Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M.; Wang, Evelyn N.

    2016-01-01

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes. PMID:26796523

  14. Chemoselective single-site Earth-abundant metal catalysts at metal-organic framework nodes.

    Science.gov (United States)

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X; Urban, Ania; Thacker, Nathan C; Lin, Wenbin

    2016-08-30

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal-organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C-H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals.

  15. Metal-Organic Framework-Based Membranes for the Separation of Light Gases

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, M.; Culp, J.T.; Smith, M.R.; Bockrath, B.C.

    2007-10-01

    Metal-organic-frameworks (MOFs) are a class of coordination compounds which exhibit high porosity and a regular crystalline geometry resulting in open pore channels and high surface area. Pore sizes are typically on the order of molecular diameters and MOF pore surfaces are known to adsorb gases such as hydrogen, nitrogen, methane and carbon dioxide. These characteristics make them potential candidates for use as gas separation membranes. In this presentation, we will discuss our results on the use of MOFs as membranes for the separation of light gases. Specifically, membranes of Cu3(benzene-1,3,5-tricarboxylate)2 were fabricated and gas permeance experiments were performed. Experimental results indicate selectivity for adsorbing gases and potential transport mechanisms will be discussed.

  16. Experimental comparison of chiral metal-organic framework used as stationary phase in chromatography.

    Science.gov (United States)

    Xie, Sheng-Ming; Zhang, Mei; Fei, Zhi-Xin; Yuan, Li-Ming

    2014-10-10

    Chiral metal-organic frameworks (MOFs) are a new class of multifunctional material, which possess diverse structures and unusual properties such as high surface area, uniform and permanent cavities, as well as good chemical and thermal stability. Their chiral functionality makes them attractive as novel enantioselective adsorbents and stationary phases in separation science. In this paper, the experimental comparison of a chiral MOF [In₃O(obb)₃(HCO₂)(H₂O)] solvent used as a stationary phase was investigated in gas chromatography (GC), high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC). The potential relationship between the structure and components of chiral MOFs with their chiral recognition ability and selectivity are presented. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Detoxification of a Sulfur Mustard Simulant Using a BODIPY-Functionalized Zirconium-Based Metal-Organic Framework.

    Science.gov (United States)

    Atilgan, Ahmet; Islamoglu, Timur; Howarth, Ashlee J; Hupp, Joseph T; Farha, Omar K

    2017-07-26

    Effective detoxification of chemical warfare agents is a global necessity. As a powerful photosensitizer, a halogenated BODIPY ligand is postsynthetically appended to the Zr 6 nodes of the metal-organic framework (MOF), NU-1000, to enhance singlet oxygen generation from the MOF. The BODIPY/MOF material is then used as a heterogeneous photocatalyst to produce singlet oxygen under green LED irradiation. The singlet oxygen selectively detoxifies the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), to the less toxic sulfoxide derivative (2-chloroethyl ethyl sulfoxide, CEESO) with a half-life of approximately 2 min.

  18. Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review

    Directory of Open Access Journals (Sweden)

    Vânia André

    2017-11-01

    Full Text Available Mechanochemistry is a powerful and environmentally friendly synthetic technique successfully employed in different fields of synthetic chemistry. Application spans from organic to inorganic chemistry including the synthesis of coordination compounds. Metal-organic frameworks (MOFs are a class of compounds with numerous applications, from which we highlight herein their application in the pharmaceutical field (BioMOFs, whose importance has been growing and is now assuming a relevant and promising domain. The need to find cleaner, greener and more energy and material-efficient synthetic procedures led to the use of mechanochemistry into the synthesis of BioMOFs.

  19. Fast and scalable synthesis of uniform zirconium-, hafnium-based metal-organic framework nanocrystals.

    Science.gov (United States)

    He, Ting; Xu, Xiaobin; Ni, Bing; Wang, Haiqing; Long, Yong; Hu, Wenping; Wang, Xun

    2017-12-14

    Metal-organic frameworks based on zirconium or hafnium possess tantalizing commercial prospects due to their high stability but require a long reaction time to form crystals. The fast synthesis of uniform Zr-, Hf-MOF nanocrystals at scale is of key importance in the potential commercial application of MOFs. In this work, we have developed a versatile strategy through controlling the hydrolysis and nucleation of metal salts in the presence of acetic acid and water; up to 24 grams of UiO-66-NH 2 nanocrystals with a uniform octahedron could be synthesized within 15 minutes using a one step method. The current synthetic strategy could be extended to other Zr-, Hf-MOF nanocrystals [UiO-66-Fast, UiO-66-(OH) 2 -Fast, UiO-66-2,6-NDC-Fast, UiO-67-Fast, BUT-12-Fast, PCN-222-Ni-Fast, PCN-222-Co-Fast, Hf-UiO-66-Fast, Hf-UiO-66-NH 2 -Fast, Hf-UiO-66-(OH) 2 -Fast, Hf-UiO-66-2,6-NDC-Fast and Hf-BUT-12-Fast]. Significantly, when noble metal nanoparticles (NPs) are introduced into MOF precursors, NPs encapsulated in MOFs with excellent dispersion have also been obtained and show outstanding performance in catalysis. This facile procedure is expected to pave the way to expand the commercial applications of MOFs.

  20. Microstructural Engineering and Architectural Design of Metal-Organic Framework Membranes.

    Science.gov (United States)

    Liu, Yi; Ban, Yujie; Yang, Weishen

    2017-08-01

    In the past decade, a huge development in rational design, synthesis, and application of molecular sieve membranes, which typically included zeolites, metal-organic frameworks (MOFs), and graphene oxides, has been witnessed. Owing to high flexibility in both pore apertures and functionality, MOFs in the form of membranes have offered unprecedented opportunities for energy-efficient gas separations. Reports on the fabrication of well-intergrown MOF membranes first appeared in 2009. Since then there has been tremendous growth in this area along with an exponential increase of MOF-membrane-related publications. In order to compete with other separation and purification technologies, like cryogenic distillation, pressure swing adsorption, and chemical absorption, separation performance (including permeability, selectivity, and long-term stability) of molecular sieve membranes must be further improved in an attempt to reach an economically attractive region. Therefore, microstructural engineering and architectural design of MOF membranes at mesoscopic and microscopic levels become indispensable. This review summarizes some intriguing research that may potentially contribute to large-scale applications of MOF membranes in the future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Structure and applications of metal-organic framework based on cyanide and 3,5-dichloropyridine

    Science.gov (United States)

    Etaiw, Safaa El-din H.; El-bendary, Mohamed M.

    2013-06-01

    The reaction of the aqueous/acetonitrile solutions of K3[Cu(CN)4] and 3,5-dichloropyridine (3,5-dClpy), in the presence of Me3SnCl affords a new metal-organic framework (MOF), 3∞[(CuCN)2·(3,5-dClpy)2], 1. The structure of the MOF 1 was characterized by IR, UV-visible, TGA and X-ray single crystal analysis. The structure of MOF 1 consists of CuCN building blocks which are connected by CN group forming 1D-zig-zag chains. Each chain is bridged to another chain by hydrogen bonding organizing 2D-sheets. The structure of 1 is further close packed by hydrogen bonds, π-π stacking and lp-π interactions creating 3D-network. The emission spectra and the thermodynamic parameters from TGA of the MOF 1 were discussed. The MOF 1 was used as heterogeneous catalyst for the oxidative discoloration of methylene blue dye (MB) by dilute solution of hydrogen peroxide as oxidant. The in vitro cytotoxic activity has been evaluated against the human breast cancer cell lines MCF-7. The cytotoxic effect of the MOF 1 on the viability of MCF-7 cells was determined by MTT assay.

  2. Metal-Organic Frameworks Supported on Nanofiber for Desalination by Direct Contact Membrane Distillation.

    Science.gov (United States)

    Yang, Fan; Efome, Johnson E; Rana, Dipak; Matsuura, Takeshi; Lan, Christopher

    2018-03-22

    Among other applications, metal-organic frameworks (MOFs) are slowly gaining grounds as fillers for desalination composite membranes. In this study, superhydrophobic poly(vinylidene fluoride) nanofibrous membranes were fabricated with MOF (iron 1,3,5-benzenetricarboxylate) loading of up to 5 wt % via electrospinning on a nonwoven substrate. To improve the attachment of nanofibers onto the substrate, a substrate pretreatment method called "solvent basing" was employed. The iron content in the nanofiber, measured by energy-dispersive X-ray spectroscopy, increased proportionally with the increase of the MOF concentration in the spinning dope, indicating a uniform distribution of MOF in the nanofiber. The water contact angle increased up to 138.06 ± 2.18° upon the incorporation of 5 wt % MOF, and a liquid entry pressure of 82.73 kPa could be maintained, making the membrane useful for direct contact membrane distillation experiments. The membrane was stable for the entire operating period of 5 h, exhibiting 2.87 kg/m 2 ·h of water vapor flux and 99.99% NaCl (35 g/L) rejection when the feed and permeate temperature were 48 and 16 °C, respectively. Immobilization of MOF on nanofibers with the enhanced attachment was proven by inductively coupled mass spectrometry analysis, by which no Fe 2+ could be found in the permeate to the detection limit of ppt.

  3. Complex Nanostructures from Materials based on Metal-Organic Frameworks for Electrochemical Energy Storage and Conversion.

    Science.gov (United States)

    Guan, Bu Yuan; Yu, Xin Yao; Wu, Hao Bin; Lou, Xiong Wen David

    2017-12-01

    Metal-organic frameworks (MOFs) have drawn tremendous attention because of their abundant diversity in structure and composition. Recently, there has been growing research interest in deriving advanced nanomaterials with complex architectures and tailored chemical compositions from MOF-based precursors for electrochemical energy storage and conversion. Here, a comprehensive overview of the synthesis and energy-related applications of complex nanostructures derived from MOF-based precursors is provided. After a brief summary of synthetic methods of MOF-based templates and their conversion to desirable nanostructures, delicate designs and preparation of complex architectures from MOFs or their composites are described in detail, including porous structures, single-shelled hollow structures, and multishelled hollow structures, as well as other unusual complex structures. Afterward, their applications are discussed as electrode materials or catalysts for lithium-ion batteries, hybrid supercapacitors, water-splitting devices, and fuel cells. Lastly, the research challenges and possible development directions of complex nanostructures derived from MOF-based-templates for electrochemical energy storage and conversion applications are outlined. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Destruction of chemical warfare agents using metal-organic frameworks

    Science.gov (United States)

    Mondloch, Joseph E.; Katz, Michael J.; Isley, William C., III; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W.; Hall, Morgan G.; Decoste, Jared B.; Peterson, Gregory W.; Snurr, Randall Q.; Cramer, Christopher J.; Hupp, Joseph T.; Farha, Omar K.

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic ZrIV ions as the active sites and to their superb accessibility as a defining element of their efficacy.

  5. Xenon Recovery at Room Temperature using Metal-Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Elsaidi, Sameh K. [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; Chemistry Department, Faculty of Science, Alexandria University, P. O. Box 426 Ibrahimia Alexandria 21321 Egypt; Ongari, Daniele [Laboratory of Molecular Simulation, Institut des Sciences et Ingeénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de l' Industrie 17 1951 Sion Valais Switzerland; Xu, Wenqian [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Mohamed, Mona H. [Chemistry Department, Faculty of Science, Alexandria University, P. O. Box 426 Ibrahimia Alexandria 21321 Egypt; Haranczyk, Maciej [IMDEA Materials Institute, c/Eric Kandel 2 28906 Getafe, Madrid Spain; Thallapally, Praveen K. [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA

    2017-07-24

    Xenon is known to be a very efficient anesthetic gas but its cost prohibits the wider use in medical industry and other potential applications. It has been shown that Xe recovery and recycle from anesthetic gas mixture can significantly reduce its cost as anesthetic. The current technology uses series of adsorbent columns followed by low temperature distillation to recover Xe, which is expensive to use in medical facilities. Herein, we propose much efficient and simpler system to recover and recycle Xe from simulant exhale anesthetic gas mixture at room temperature using metal organic frameworks. Among the MOFs tested, PCN-12 exhibits unprecedented performance with high Xe capacity, Xe/O2, Xe/N2 and Xe/CO2 selectivity at room temperature. The in-situ synchrotron measurements suggest the Xe is occupied in the small pockets of PCN-12 compared to unsaturated metal centers (UMCs). Computational modeling of adsorption further supports our experimental observation of Xe binding sites in PCN-12.

  6. Ligand flexibility and framework rearrangement in a new family of porous metal-organic frameworks

    DEFF Research Database (Denmark)

    Hawxwell, Samuel M; Espallargas, Guillermo Mínguez; Bradshaw, Darren

    2007-01-01

    Ligand flexibility permits framework rearrangement upon evacuation and gas uptake in a new family of porous MOFs.......Ligand flexibility permits framework rearrangement upon evacuation and gas uptake in a new family of porous MOFs....

  7. [Ti8Zr2O12(COO)16] Cluster: An Ideal Inorganic Building Unit for Photoactive Metal-Organic Frameworks.

    Science.gov (United States)

    Yuan, Shuai; Qin, Jun-Sheng; Xu, Hai-Qun; Su, Jie; Rossi, Daniel; Chen, Yuanping; Zhang, Liangliang; Lollar, Christina; Wang, Qi; Jiang, Hai-Long; Son, Dong Hee; Xu, Hongyi; Huang, Zhehao; Zou, Xiaodong; Zhou, Hong-Cai

    2018-01-24

    Metal-organic frameworks (MOFs) based on Ti-oxo clusters (Ti-MOFs) represent a naturally self-assembled superlattice of TiO 2 nanoparticles separated by designable organic linkers as antenna chromophores, epitomizing a promising platform for solar energy conversion. However, despite the vast, diverse, and well-developed Ti-cluster chemistry, only a scarce number of Ti-MOFs have been documented. The synthetic conditions of most Ti-based clusters are incompatible with those required for MOF crystallization, which has severely limited the development of Ti-MOFs. This challenge has been met herein by the discovery of the [Ti 8 Zr 2 O 12 (COO) 16 ] cluster as a nearly ideal building unit for photoactive MOFs. A family of isoreticular photoactive MOFs were assembled, and their orbital alignments were fine-tuned by rational functionalization of organic linkers under computational guidance. These MOFs demonstrate high porosity, excellent chemical stability, tunable photoresponse, and good activity toward photocatalytic hydrogen evolution reactions. The discovery of the [Ti 8 Zr 2 O 12 (COO) 16 ] cluster and the facile construction of photoactive MOFs from this cluster shall pave the way for the development of future Ti-MOF-based photocatalysts.

  8. Versatile Surface Functionalization of Metal-Organic Frameworks through Direct Metal Coordination with a Phenolic Lipid Enables Diverse Applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wei [Univ. of New Mexico, Albuquerque, NM (United States); Xiang, Guolei [Univ. of Cambridge (United Kingdom); Shang, Jin [Univ. of Hong Kong (China); Guo, Jimin [Univ. of New Mexico, Albuquerque, NM (United States); Motevalli, Benyamin [Monash Univ., Clayton, VIC (Australia); Durfee, Paul [Univ. of New Mexico, Albuquerque, NM (United States); Agola, Jacob Ongudi [Univ. of New Mexico, Albuquerque, NM (United States); Coker, Eric N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brinker, C. Jeffrey [Univ. of New Mexico, Albuquerque, NM (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-22

    Here, a novel strategy for the versatile functionalization of the external surface of metal-organic frameworks (MOFs) has been developed based on the direct coordination of a phenolic-inspired lipid molecule DPGG (1,2-dipalmitoyl-sn-glycero-3-galloyl) with metal nodes/sites surrounding MOF surface. X-ray diffraction and Argon sorption analysis prove that the modified MOF particles retain their structural integrity and porosity after surface modification. Density functional theory calculations reveal that strong chelation strength between the metal sites and the galloyl head group of DPGG is the basic prerequisite for successful coating. Due to the pH-responsive nature of metal-phenol complexation, the modification process is reversible by simple washing in weak acidic water, showing an excellent regeneration ability for water-stable MOFs. Moreover, the colloidal stability of the modified MOFs in the nonpolar solvent allows them to be further organized into 2 dimensional MOF or MOF/polymer monolayers by evaporation-induced interfacial assembly conducted on an air/water interface. Lastly, the easy fusion of a second functional layer onto DPGG-modified MOF cores, enabled a series of MOF-based functional nanoarchitectures, such as MOFs encapsulated within hybrid supported lipid bilayers (so-called protocells), polyhedral core-shell structures, hybrid lipid-modified-plasmonic vesicles and multicomponent supraparticles with target functionalities, to be generated. for a wide range of applications.

  9. A bio-metal-organic framework for highly selective CO(2) capture: A molecular simulation study.

    Science.gov (United States)

    Chen, Yifei; Jiang, Jianwen

    2010-08-23

    A recently synthesized bio-metal-organic framework (bio-MOF-11) is investigated for CO(2) capture by molecular simulation. The adenine biomolecular linkers in bio-MOF-11 contain Lewis basic amino and pyrimidine groups as the preferential adsorption sites. The simulated and experimental adsorption isotherms of pure CO(2), H(2), and N(2) are in perfect agreement. Bio-MOF-11 exhibits larger adsorption capacities compared to numerous zeolites, activated carbons, and MOFs, which is attributed to the presence of multiple Lewis basic sites and nano-sized channels. The results for the adsorption of CO(2)/H(2) and CO(2)/N(2) mixtures in bio-MOF-11 show that CO(2) is more dominantly adsorbed than H(2) and N(2). With increasing pressure, the selectivity of CO(2)/H(2) initially increases owing to the strong interactions between CO(2) and the framework, and then decreases as a consequence of the entropy effect. However, the selectivity of CO(2)/N(2) monotonically increases with increasing pressure and finally reaches a constant. The selectivities in bio-MOF-11 are higher than in many nanoporous materials. The simulation results also reveal that a small amount of H(2)O has a negligible effect on the separation of CO(2)/H(2) and CO(2)/N(2) mixtures. The simulation study provides quantitative microscopic insight into the adsorption mechanism in bio-MOF-11 and suggests that bio-MOF-11 may be interesting for pre- and post-combustion CO(2) capture.

  10. Preparation, Characterization, and Postsynthetic Modification of Metal-Organic Frameworks: Synthetic Experiments for an Undergraduate Laboratory Course in Inorganic Chemistry

    Science.gov (United States)

    Sumida, Kenji; Arnold, John

    2011-01-01

    Metal-organic frameworks (MOFs) are crystalline materials that are composed of an infinite array of metal nodes (single ions or clusters) linked to one another by polyfunctional organic compounds. Because of their extraordinary surface areas and high degree of control over the physical and chemical properties, these materials have received much…

  11. Metal-directed topological diversity of three fluorescent metal-organic frameworks based on a new tetracarboxylate strut

    KAUST Repository

    Lou, Xinhua

    2013-01-01

    Three d- or p-block metal ions based metal-organic frameworks (MOFs) were isolated by employing a new tetracarboxylate linker, featuring unusual flu, self-interpenetrated lvt and new (3,5)-c topological nets, respectively. Interesting photoluminescent properties of these solid-state materials were also observed. © 2013 The Royal Society of Chemistry.

  12. Metal organic frameworks for enzyme immobilization in biofuel cells

    Science.gov (United States)

    Bodell, JaDee

    Interest in biofuel cells has been rapidly expanding as an ever-growing segment of the population gains access to electronic devices. The largest areas of growth for new populations using electronic devices are often in communities without electrical infrastructure. This lack of infrastructure in remote environments is one of the key driving factors behind the development of biofuel cells. Biofuel cells employ biological catalysts such as enzymes to catalyze oxidation and reduction reactions of select fuels to generate power. There are several benefits to using enzymes to catalyze reactions as compared to traditional fuel cells which use metal catalysts. First, enzymes are able to catalyze reactions at or near room temperature, whereas traditional metal catalysts are only efficient at very high temperatures. Second, biofuel cells can operate under mild pH conditions which is important for the eventual design of safe, commercially viable devices. Also, biofuel cells allow for implantable and flexible technologies. Finally, enzymes exhibit high selectivity and can be combined to fully oxidize or reduce the fuel which can generate several electrons from a single molecule of fuel, increasing the overall device efficiency. One of the main challenges which persist in biofuel cells is the instability of enzymes over time which tend to denature after hours or days. For a viable commercial biofuel cell to be produced, the stability of enzymes must be extended to months or years. Enzymes have been shown to have improved stability after being immobilized. The focus of this research was to find a metal organic framework (MOF) structure which could successfully immobilize enzymes while still allowing for electron transport to occur between the catalytic center of the enzyme and the electrode surface within a biofuel cell for power generation. Four MOF structures were successfully synthesized and were subsequently tested to determine the MOF's ability to immobilize the following

  13. Organelle-Specific Triggered Release of Immunostimulatory Oligonucleotides from Intrinsically Coordinated DNA-Metal-Organic Frameworks with Soluble Exoskeleton.

    Science.gov (United States)

    Wang, Zejun; Fu, Yao; Kang, Zhengzhong; Liu, Xiaoguo; Chen, Nan; Wang, Qi; Tu, Yaoquan; Wang, Lihua; Song, Shiping; Ling, Daishun; Song, Haiyun; Kong, Xueqian; Fan, Chunhai

    2017-11-08

    DNA has proven of high utility to modulate the surface functionality of metal-organic frameworks (MOFs) for various biomedical applications. Nevertheless, current methods for preparing DNA-MOF nanoparticles rely on either inefficient covalent conjugation or specific modification of oligonucleotides. In this work, we report that unmodified oligonucleotides can be loaded on MOFs with high density (∼2500 strands/particle) via intrinsic, multivalent coordination between DNA backbone phosphate and unsaturated zirconium sites on MOFs. More significantly, surface-bound DNA can be efficiently released in either bulk solution or specific organelles in live cells when free phosphate ions are present. As a proof-of-concept for using this novel type of DNA-MOFs in immunotherapy, we prepared a construct of immunostimulatory DNA-MOFs (isMOFs) by intrinsically coordinating cytosine-phosphate-guanosine (CpG) oligonucleotides on biocompatible zirconium MOF nanoparticles, which was further armed by a protection shell of calcium phosphate (CaP) exoskeleton. We demonstrated that isMOFs exhibited high cellular uptake, organelle specificity, and spatiotemporal control of Toll-like receptors (TLR)-triggered immune responses. When isMOF reached endolysosomes via microtubule-mediated trafficking, the CaP exoskeleton dissolved in the acidic environment and in situ generated free phosphate ions. As a result, CpG was released from isMOFs and stimulated potent immunostimulation in living macrophage cells. Compared with naked CpG-MOF, isMOFs exhibited 83-fold up-regulation in stimulated secretion of cytokines. We thus expect this isMOF design with soluble CaP exoskeleton and an embedded sequential "protect-release" program provides a highly generic approach for intracellular delivery of therapeutic nucleic acids.

  14. Metal-Organic Frameworks as Potential Platforms for Carbon Dioxide Capture and Chemical Transformation

    Science.gov (United States)

    Gao, Wenyang

    The anthropogenic carbon dioxide (CO2) emission into the atmosphere, mainly through the combustion of fossil fuels, has resulted in a balance disturbance of the carbon cycle. Overwhelming scientific evidence proves that the escalating level of atmospheric CO2 is deemed as the main culprit for global warming and climate change. It is thus imperative to develop viable CO2 capture and sequestration (CCS) technologies to reduce CO2 emissions, which is also essential to avoid the potential devastating effects in future. The drawbacks of energy-cost, corrosion and inefficiency for amine-based wet-scrubbing systems which are currently used in industry, have prompted the exploration of alternative approaches for CCS. Extensive efforts have been dedicated to the development of functional porous materials, such as activated carbons, zeolites, porous organic polymers, and metal-organic frameworks (MOFs) to capture CO2. However, these adsorbents are limited by either poor selectivity for CO2 separation from gas mixtures or low CO2 adsorption capacity. Therefore, it is still highly demanding to design next-generation adsorbent materials fulfilling the requirements of high CO2 selectivity and enough CO2 capacity, as well as high water/moisture stability under practical conditions. Metal-organic frameworks (MOFs) have been positioned at the forefront of this area as a promising type of candidate amongst various porous materials. This is triggered by the modularity and functionality of pore size, pore walls and inner surface of MOFs by use of crystal engineering approaches. In this work, several effective strategies, such as incorporating 1,2,3-triazole groups as moderate Lewis base centers into MOFs and employing flexible azamacrocycle-based ligands to build MOFs, demonstrate to be promising ways to enhance CO 2 uptake capacity and CO2 separation ability of porous MOFs. It is revealed through in-depth studies on counter-intuitive experimental observations that the local electric

  15. Anisotropic thermal expansion in a metal-organic framework.

    Science.gov (United States)

    Madsen, Solveig Røgild; Lock, Nina; Overgaard, Jacob; Iversen, Bo Brummerstedt

    2014-06-01

    Ionothermal reaction between Mn(II)(acetate)2·4H2O and 1,3,5-benzenetricarboxylic acid (H3BTC) in either of the two ionic liquids 1-ethyl-3-methylimidazolium bromide (EMIMBr) and 1-ethyl-3-methylimidazolium tosylate (EMIMOTs) resulted in the formation of the new metal-organic framework (MOF) EMIM[Mn(II)BTC] (BTC = 1,3,5-benzenetricarboxylate). The compound crystallizes in the orthorhombic space group Pbca with unit-cell parameters of a = 14.66658 (12), b = 12.39497 (9), c = 16.63509 (14) Å at 100 K. Multi-temperature single-crystal (15-340 K) and powder X-ray diffraction studies (100-400 K) reveal strongly anisotropic thermal expansion properties. The linear thermal expansion coefficients, αL(l), attain maximum values at 400 K along the a- and b-axis, with αL(a) = 115 × 10(-6) K(-1) and αL(b) = 75 × 10(-6) K(-1). At 400 K a negative thermal expansion coefficient of -40 × 10(-6) K(-1) is observed along the c-axis. The thermal expansion is coupled to a continuous deformation of the framework, which causes the structure to expand in two directions. Due to the rigidity of the linker, the expansion in the ab plane causes the network to contract along the c-axis. Hirshfeld surface analysis has been used to describe the interaction between the framework structure and the EMIM cation that resides within the channel. This reveals a number of rather weak interactions and one governing hydrogen-bonding interactions.

  16. Metal-organic frameworks in mixed-matrix membranes for gas separation.

    Science.gov (United States)

    Tanh Jeazet, Harold B; Staudt, Claudia; Janiak, Christoph

    2012-12-14

    Mixed-matrix membranes (MMMs) with metal-organic frameworks (MOFs) as additives (fillers) exhibit enhanced gas permeabilities and possibly also selectivities when compared to the pure polymer. Polyimides (Matrimid®) and polysulfones are popular polymer matrices for MOF fillers. Presently investigated MOFs for MMMs include [Cu(SiF(6))(4,4'-BIPY)(2)], [Cu(3)(BTC)(2)(H(2)O)(3)] (HKUST-1, Cu-BTC), [Cu(BDC)(DMF)], [Zn(4)O(BDC)(3)] (MOF-5), [Zn(2-methylimidazolate)(2)] (ZIF-8), [Zn(purinate)(2)] (ZIF-20), [Zn(2-carboxyaldehyde imidazolate)(2)] (ZIF-90), Mn(HCOO)(2), [Al(BDC)(μ-OH)] (MIL-53(Al)), [Al(NH(2)-BDC)(μ-OH)] (NH(2)-MIL-53(Al)) and [Cr(3)O(BDC)(3)(F,OH)(H(2)O)(2)] (MIL-101) (4,4'-BIPY = 4,4'-bipyridine, BTC = benzene-1,3,5-tricarboxylate, BDC = benzene-1,4-dicarboxylate, terephthalate). MOF particle adhesion to polyimide and polysulfone organic polymers does not represent a problem. MOF-polymer MMMs are investigated for the permeability of the single gases H(2), N(2), O(2), CH(4), CO(2) and of the gas mixtures O(2)/N(2), H(2)/CH(4), CO(2)/CH(4), H(2)/CO(2), CH(4)/N(2) and CO(2)/N(2) (preferentially permeating gas named first). Permeability increases can be traced to the MOF porosity. Since the porosity of MOFs can be tuned very precisely, which is not possible with polymeric material, MMMs offer the opportunity of significantly increasing the selectivity compared to the pure polymeric matrix. Additionally in most of the cases the permeability is increased for MMM membranes compared to the pure polymer. Addition of MOFs to polymers in MMMs easily yields performances similar to the best polymer membranes and gives higher selectivities than those reported to date for any pure MOF membrane for the same gas separation. MOF-polymer MMMs allow for easier synthesis and handability compared to pure MOF membranes.

  17. Zeolite-like metal-organic frameworks with ana topology

    KAUST Repository

    Eddaoudi, Mohamed

    2017-04-20

    Embodiments of the present disclosure describe a zeolite-like metal-organic framework composition comprising a metal-organic framework composition with ana topology characterized by the formula [MIII(4, 5-imidazole dicarboxylic acid)2X(solvent)a]n wherein MIII comprises a trivalent cation of a rare earth element, X comprises an alkali metal element or alkaline earth metal element, and solvent comprises a guest molecule occupying pores. Embodiments of the present disclosure describe a method of separating paraffins comprising contacting a zeolite-like metal-organic framework with ana topology with a flow of paraffins, and separating the paraffins by size.

  18. Metal-organic frameworks for analytical chemistry: from sample collection to chromatographic separation.

    Science.gov (United States)

    Gu, Zhi-Yuan; Yang, Cheng-Xiong; Chang, Na; Yan, Xiu-Ping

    2012-05-15

    In modern analytical chemistry researchers pursue novel materials to meet analytical challenges such as improvements in sensitivity, selectivity, and detection limit. Metal-organic frameworks (MOFs) are an emerging class of microporous materials, and their unusual properties such as high surface area, good thermal stability, uniform structured nanoscale cavities, and the availability of in-pore functionality and outer-surface modification are attractive for diverse analytical applications. This Account summarizes our research on the analytical applications of MOFs ranging from sampling to chromatographic separation. MOFs have been either directly used or engineered to meet the demands of various analytical applications. Bulk MOFs with microsized crystals are convenient sorbents for direct application to in-field sampling and solid-phase extraction. Quartz tubes packed with MOF-5 have shown excellent stability, adsorption efficiency, and reproducibility for in-field sampling and trapping of atmospheric formaldehyde. The 2D copper(II) isonicotinate packed microcolumn has demonstrated large enhancement factors and good shape- and size-selectivity when applied to on-line solid-phase extraction of polycyclic aromatic hydrocarbons in water samples. We have explored the molecular sieving effect of MOFs for the efficient enrichment of peptides with simultaneous exclusion of proteins from biological fluids. These results show promise for the future of MOFs in peptidomics research. Moreover, nanosized MOFs and engineered thin films of MOFs are promising materials as novel coatings for solid-phase microextraction. We have developed an in situ hydrothermal growth approach to fabricate thin films of MOF-199 on etched stainless steel wire for solid-phase microextraction of volatile benzene homologues with large enhancement factors and wide linearity. Their high thermal stability and easy-to-engineer nanocrystals make MOFs attractive as new stationary phases to fabricate MOF

  19. Targeted Construction of Light-Harvesting Metal-Organic Frameworks Featuring Efficient Host-Guest Energy Transfer.

    Science.gov (United States)

    Zhao, Xiaoyu; Song, Xiaoyu; Li, Yang; Chang, Ze; Chen, Long

    2018-02-14

    Metal-organic frameworks (MOFs) have emerged as promising light-harvesting platforms for energy-transfer materials. However, the targeted construction of MOFs with desirable photophysical properties and pore structures is still a challenge. Herein, 1,1,2,2-tetrakis(4-(pyridin-4-yl)phenyl)ethene (tppe) is selected as the ligand for the construction of light-harvesting MOFs due to its highly emissive and rigid backbone, which could benefit the light-harvesting performance of the MOFs. Three MOFs (MOFs 1-3) were obtained on the basis of different metal centers (Zn 2+ and Cd 2+ ) and carboxylate building blocks. The complete structure characterization of the MOFs helps the illustration of the principles for structure tuning of this system. All three MOFs exhibit strong tppe-originated photoluminescence emission, with quantum yields as high as 47.6%. The fluorescence quantum yield and time-resolved fluorescence studies reveal that a remarkable energy-transfer efficiency (up to 96%) was achieved in this system. These results clearly indicate tppe-MOFs could be promising light-harvesting materials.

  20. Kinetic-Controlled Formation of Bimetallic Metal-Organic Framework Hybrid Structures.

    Science.gov (United States)

    Guo, Wenhan; Xia, Wei; Cai, Kunting; Wu, Yingxiao; Qiu, Bin; Liang, Zibin; Qu, Chong; Zou, Ruqiang

    2017-11-01

    Heterometallic metal-organic frameworks (MOFs) are constructed from two or more kinds of metal ions, while still remaining their original topologies. Due to distinct reaction kinetics during MOF formation, partial distribution of different metals within a single MOF crystal can lead to sophisticated heterogeneous nanostructures. Here, this study reports an investigation of reaction kinetics for different metal ions in a bimetallic MOF system, the ZIF-8/67 (M(2-mIM) 2 , M = Zn for ZIF-8, and Co for ZIF-67, 2-mIM = 2-methylimidazole), by in situ optical method. Distinct kinetics of the two metals forming single-component MOFs are revealed, and when both Co and Zn ions are present in the starting solution, homogeneous distributions of the two metals are only achieved at high Co/Zn ratio, while at low Co/Zn ratio concentration gradient from Co-rich cores to Zn-rich shells is observed. Further, by adding the two metals in sequence, more sophisticated structures are achieved. Specifically, when Co 2+ is added first, ZIF-67@ZIF-8/67 core-shell nanocrystals are achieved with tunable core/shell thickness ratio depending on the time intervals; while when Zn 2+ is added first, only agglomerates of irregular shape form due to the weak nucleation ability of Zn 2+ . © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Metal-Organic Frameworks for Cultural Heritage Preservation: The Case of Acetic Acid Removal.

    Science.gov (United States)

    Dedecker, Kevin; Pillai, Renjith S; Nouar, Farid; Pires, João; Steunou, Nathalie; Dumas, Eddy; Maurin, Guillaume; Serre, Christian; Pinto, Moisés L

    2018-04-11

    The removal of low concentrations of acetic acid from indoor air at museums poses serious preservation problems that the current adsorbents cannot easily address owing to their poor affinity for acetic acid and/or their low adsorption selectivity versus water. In this context, a series of topical water-stable metal-organic frameworks (MOFs) with different pore sizes, topologies, hydrophobic characters, and functional groups was explored through a joint experimental-computational exploration. We demonstrate how a subtle combination of sufficient hydrophobicity and optimized host-guest interactions allows one to overcome the challenge of capturing traces of this very polar volatile organic compound in the presence of humidity. The optimal capture of acetic acid was accomplished with MOFs that do not show polar groups in the inorganic node or have lipophilic but polar (e.g., perfluoro) groups functionalized to the organic linkers, that is, the best candidates from the list of explored MOFs are MIL-140B and UiO-66-2CF 3 . These two MOFs present the appropriate pore size to favor a high degree of confinement, together with organic spacers that allow an enhancement of the van der Waals interactions with the acetic acid. We establish in this work that MOFs can be a viable solution to this highly challenging problem in cultural heritage protection, which is a new field of application for this type of hybrid materials.

  2. Luminescent Metal-Organic-Framework-Based Label-Free Assay of Polyphenol Oxidase with Fluorescent Scan.

    Science.gov (United States)

    Li, Yue; Guo, An; Chang, Lan; Li, Wen-Juan; Ruan, Wen-Juan

    2017-05-11

    Metal-organic frameworks (MOFs) are emerging in recent years as a kind of versatile fluorescent sensing materials, but their application to enzyme assays has rarely been studied. Here, the first example of a MOF-based label-free enzyme assay system is reported. A luminescent MOF was synthesized and applied to the activity analysis of polyphenol oxidase (PPO). With its distinct responses to the phenolic substrate and o-quinone product, this MOF could transduce the extent of PPO-catalyzed oxidation to fluorescence signal and enable the real-time monitoring of this reaction. Wide substrate adaptability and high sensitivity (detection limit=0.00012 U mL -1 ) were exhibited by this method, which meets the requirement of common bioanalysis. Interestingly, by the comparison with molecular capturing reagents, the heterogeneous nature of this MOF-based assay effectively preventing the interaction with the enzyme was proven, thus ensuring the authenticity of results. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. First-principles Hubbard U approach for small molecule binding in metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Gregory W., E-mail: gmann@berkeley.edu [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Mesosphere, Inc., San Francisco, California 94105 (United States); Lee, Kyuho, E-mail: kyuholee@lbl.gov [Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720 (United States); Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Synopsys, Inc., Mountain View, California 94043 (United States); Cococcioni, Matteo, E-mail: matteo.cococcioni@epfl.ch [Theory and Simulation of Materials (THEOS), École Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Smit, Berend, E-mail: Berend-Smit@berkeley.edu [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720 (United States); Laboratory of Molecular Simulation, Institut des Sciences et Ingénierie Chimiques, Valais Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de l’Industrie 17, CH-1951 Sion (Switzerland); Neaton, Jeffrey B., E-mail: jbneaton@lbl.gov [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States); Kavli Energy NanoSciences Institute at Berkeley, Berkeley, California 94720 (United States)

    2016-05-07

    We apply first-principles approaches with Hubbard U corrections for calculation of small molecule binding energetics to open-shell transition metal atoms in metal-organic frameworks (MOFs). Using density functional theory with van der Waals dispersion-corrected functionals, we determine Hubbard U values ab initio through an established linear response procedure for M-MOF-74, for a number of different metal centers (M = Ti, V, Cr, Mn, Fe, Co, Ni, and Cu). While our ab initio U values differ from those used in previous work, we show that they result in lattice parameters and electronic contributions to CO{sub 2}-MOF binding energies that lead to excellent agreement with experiments and previous results, yielding lattice parameters within 3%. In addition, U-dependent calculations for an example system, Co-MOF-74, suggest that the CO{sub 2} binding energy grows monotonically with the value of Hubbard U, with the binding energy shifting 4 kJ/mol (or 0.041 eV) over the range of U = 0-5.4 eV. These results provide insight into an approximate but computationally efficient means for calculation of small molecule binding energies to open-shell transition metal atoms in MOFs and suggest that the approach can be predictive with good accuracy, independent of the cations used and the availability of experimental data.

  4. Recent Progress in Metal-Organic Frameworks for Applications in Electrocatalytic and Photocatalytic Water Splitting.

    Science.gov (United States)

    Wang, Wei; Xu, Xiaomin; Zhou, Wei; Shao, Zongping

    2017-04-01

    The development of clean and renewable energy materials as alternatives to fossil fuels is foreseen as a potential solution to the crucial problems of environmental pollution and energy shortages. Hydrogen is an ideal energy material for the future, and water splitting using solar/electrical energy is one way to generate hydrogen. Metal-organic frameworks (MOFs) are a class of porous materials with unique properties that have received rapidly growing attention in recent years for applications in water splitting due to their remarkable design flexibility, ultra-large surface-to-volume ratios and tunable pore channels. This review focuses on recent progress in the application of MOFs in electrocatalytic and photocatalytic water splitting for hydrogen generation, including both oxygen and hydrogen evolution. It starts with the fundamentals of electrocatalytic and photocatalytic water splitting and the related factors to determine the catalytic activity. The recent progress in the exploitation of MOFs for water splitting is then summarized, and strategies for designing MOF-based catalysts for electrocatalytic and photocatalytic water splitting are presented. Finally, major challenges in the field of water splitting are highlighted, and some perspectives of MOF-based catalysts for water splitting are proposed.

  5. A flexible ligand-based wavy layered metal-organic framework for lithium-ion storage.

    Science.gov (United States)

    An, Tiance; Wang, Yuhang; Tang, Jing; Wang, Yang; Zhang, Lijuan; Zheng, Gengfeng

    2015-05-01

    A substantial challenge for direct utilization of metal-organic frameworks (MOFs) as lithium-ion battery anodes is to maintain the rigid MOF structure during lithiation/delithiation cycles. In this work, we developed a flexible, wavy layered nickel-based MOF (C20H24Cl2N8Ni, designated as Ni-Me4bpz) by a solvothermal approach of 3,3',5,5'-tetramethyl-4,4'-bipyrazole (H2Me4bpz) with nickel(II) chloride hexahydrate. The obtained MOF materials (Ni-Me4bpz) with metal azolate coordination mode provide 2-dimensional layered structure for Li(+) intercalation/extraction, and the H2Me4bpz ligands allow for flexible rotation feature and structural stability. Lithium-ion battery anodes made of the Ni-Me4bpz material demonstrate excellent specific capacity and cycling performance, and the crystal structure is well preserved after the electrochemical tests, suggesting the potential of developing flexible layered MOFs for efficient and stable electrochemical storage. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Ultrarobust Biochips with Metal-Organic Framework Coating for Point-of-Care Diagnosis.

    Science.gov (United States)

    Wang, Congzhou; Wang, Lu; Tadepalli, Sirimuvva; Morrissey, Jeremiah J; Kharasch, Evan D; Naik, Rajesh R; Singamaneni, Srikanth

    2018-02-23

    Most biosensors relying on antibodies as recognition elements fail in harsh environment conditions such as elevated temperatures, organic solvents, or proteases because of antibody denaturation, and require strict storage conditions with defined shelf life, thus limiting their applications in point-of-care and resource-limited settings. Here, a metal-organic framework (MOF) encapsulation is utilized to preserve the biofunctionality of antibodies conjugated to nanotransducers. This study investigates several parameters of MOF coating (including growth time, surface morphology, thickness, and precursor concentrations) that determine the preservation efficacy against different protein denaturing conditions in both dry and wet environments. A plasmonic biosensor based on gold nanorods as the nanotransducers is employed as a model biodiagnostic platform. The preservation efficacy attained through MOF encapsulation is compared to two other commonly employed materials (sucrose and silk fibroin). The results show that MOF coating outperforms sucrose and silk fibroin coatings under several harsh conditions including high temperature (80 °C), dimethylformamide, and protease solution, owing to complete encapsulation, stability in wet environment and ease of removal at point-of-use by the MOF. We believe this study will broaden the applicability of this universal approach for preserving different types of on-chip biodiagnostic reagents and biosensors/bioassays, thus extending the benefits of advanced diagnostic technologies in resource-limited settings.

  7. Metal-Organic Framework-Derived Materials for Sodium Energy Storage.

    Science.gov (United States)

    Zou, Guoqiang; Hou, Hongshuai; Ge, Peng; Huang, Zhaodong; Zhao, Ganggang; Yin, Dulin; Ji, Xiaobo

    2018-01-01

    Recently, sodium-ion batteries (SIBs) are extensively explored and are regarded as one of the most promising alternatives to lithium-ion batteries for electrochemical energy conversion and storage, owing to the abundant raw material resources, low cost, and similar electrochemical behavior of elemental sodium compared to lithium. Metal-organic frameworks (MOFs) have attracted enormous attention due to their high surface areas, tunable structures, and diverse applications in drug delivery, gas storage, and catalysis. Recently, there has been an escalating interest in exploiting MOF-derived materials as anodes for sodium energy storage due to their fast mass transport resulting from their highly porous structures and relatively simple preparation methods originating from in situ thermal treatment processes. In this Review, the recent progress of the sodium-ion storage performances of MOF-derived materials, including MOF-derived porous carbons, metal oxides, metal oxide/carbon nanocomposites, and other materials (e.g., metal phosphides, metal sulfides, and metal selenides), as SIB anodes is systematically and completely presented and discussed. Moreover, the current challenges and perspectives of MOF-derived materials in electrochemical energy storage are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Kinetic Analysis of the Uptake and Release of Fluorescein by Metal-Organic Framework Nanoparticles

    Directory of Open Access Journals (Sweden)

    Tobias Preiß

    2017-02-01

    Full Text Available Metal-organic framework nanoparticles (MOF NPs are promising guest-host materials with applications in separation, storage, catalysis, and drug delivery. However, on- and off-loading of guest molecules by porous MOF nanostructures are still poorly understood. Here we study uptake and release of fluorescein by two representative MOF NPs, MIL-100(Fe and MIL-101(Cr. Suspensions of these MOF NPs exhibit well-defined size distributions and crystallinity, as verified by electron microscopy, dynamic light scattering, and X-ray diffraction. Using absorbance spectroscopy the equilibrium dissociation constants and maximum numbers of adsorbed fluorescein molecules per NP were determined. Time-resolved fluorescence studies reveal that rates of release and loading are pH dependent. The kinetics observed are compared to theoretical estimates that account for bulk diffusion into NPs, and retarded internal diffusion and adsorption rates. Our study shows that, rather than being simple volumetric carriers, MOF-NPs are dominated by internal surface properties. The findings will help to optimize payload levels and develop release strategies that exploit varying pH for drug delivery.

  9. Carbon Dioxide Removal from Flue Gas Using Microporous Metal Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Lesch, David A

    2010-06-30

    UOP LLC, a Honeywell Company, in collaboration with Professor Douglas LeVan at Vanderbilt University (VU), Professor Adam Matzger at the University of Michigan (UM), Professor Randall Snurr at Northwestern University (NU), and Professor Stefano Brandani at the University of Edinburgh (UE), supported by Honeywell's Specialty Materials business unit and the Electric Power Research Institute (EPRI), have completed a three-year project to develop novel microporous metal organic frameworks (MOFs) and an associated vacuum-pressure swing adsorption (vPSA) process for the removal of CO{sub 2} from coal-fired power plant flue gas. The project leveraged the team's complementary capabilities: UOP's experience in materials development and manufacturing, adsorption process design and process commercialization; LeVan and Brandani's expertise in high-quality adsorption measurements; Matzger's experience in syntheis of MOFs and the organic components associated with MOFs; Snurr's expertise in molecular and other modeling; Honeywell's expertise in the manufacture of organic chemicals; and, EPRI's knowledge of power-generation technology and markets. The project was successful in that a selective CO{sub 2} adsorbent with good thermal stability and reasonable contaminant tolerance was discovered, and a low cost process for flue gas CO{sub 2} capture process ready to be evaluated further at the pilot scale was proposed. The team made significant progress toward the current DOE post-combustion research targets, as defined in a recent FOA issued by NETL: 90% CO{sub 2} removal with no more than a 35% increase in COE. The team discovered that favorable CO{sub 2} adsorption at more realistic flue gas conditions is dominated by one particular MOF structure type, M/DOBDC, where M designates Zn, Co, Ni, or Mg and DOBDC refers to the form of the organic linker in the resultant MOF structure, dioxybenzenedicarboxylate. The structure of the M/DOBDC MOFs

  10. Achieving Amphibious Superprotonic Conductivity in a CuI Metal-Organic Framework by Strategic Pyrazinium Salt Impregnation.

    Science.gov (United States)

    Khatua, Sajal; Bar, Arun Kumar; Sheikh, Javeed Ahmad; Clearfield, Abraham; Konar, Sanjit

    2018-01-19

    Treatment of a pyrazine (pz)-impregnated Cu I metal-organic framework (MOF) ([1⊃pz]) with HCl vapor renders an interstitial pyrazinium chloride salt-hybridized MOF ([1⊃pz⋅6 HCl]) that exhibits proton conductivity over 10 -2  S cm -1 both in anhydrous and under humid conditions. Framework [1⊃pz⋅6 HCl] features the highest anhydrous proton conductivity among the lesser-known examples of MOF-based materials exhibiting proton conductivity under both anhydrous and humid conditions. Moreover, [1⊃pz] and corresponding pyrazinium sulfate- and pyrazinium phosphate-hybridized MOFs also exhibit superprotonic conductivity over 10 -2  S cm -1 under humid conditions. The impregnated pyrazinium ions play a crucial role in protonic conductivity, which occurs through a Grotthuss mechanism. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Fuel upgrading and reforming with metal organic framework

    KAUST Repository

    Eddaoudi, Mohamed

    2016-03-31

    Systems and methods for separating hydrocarbons on an internal combustion powered vehicle via one or more metal organic frameworks are disclosed. Systems and methods can further include utilizing separated hydrocarbons and exhaust to generate hydrogen gas for use as fuel. In one aspect, a method for separating hydrocarbons can include contacting a first component containing a first metal organic framework with a flow of hydrocarbons and separating hydrocarbons by size. In certain embodiments, the hydrocarbons can include alkanes.

  12. Mechanical tunability via hydrogen bonding in metal-organic frameworks with the perovskite architecture.

    Science.gov (United States)

    Li, Wei; Thirumurugan, A; Barton, Phillip T; Lin, Zheshuai; Henke, Sebastian; Yeung, Hamish H-M; Wharmby, Michael T; Bithell, Erica G; Howard, Christopher J; Cheetham, Anthony K

    2014-06-04

    Two analogous metal-organic frameworks (MOFs) with the perovskite architecture, [C(NH2)3][Mn(HCOO)3] (1) and [(CH2)3NH2][Mn(HCOO)3] (2), exhibit significantly different mechanical properties. The marked difference is attributed to their distinct modes of hydrogen bonding between the A-site amine cation and the anionic framework. The stronger cross-linking hydrogen bonding in 1 gives rise to Young's moduli and hardnesses that are up to twice those in 2, while the thermal expansion is substantially smaller. This study presents clear evidence that the mechanical properties of MOF materials can be substantially tuned via hydrogen-bonding interactions.

  13. Light Hydrocarbons Adsorption Mechanisms in Two Calcium-based Microporous Metal Organic Frameworks

    KAUST Repository

    Plonka, Anna M.

    2016-01-25

    The adsorption mechanism of ethane, ethylene and acetylene (C2Hn; n=2, 4, 6) on two microporous metal organic frameworks (MOFs) is described here that is consistent with observations from single crystal and powder X-ray diffraction, calorimetric measurments and gas adsorption isotherm measurements. Two calcium-based MOFs, designated as SBMOF-1 and SBMOF-2 (SB: Stony Brook), form three-dimensional frameworks with one-dimensional open channels. As determined form single crystal diffraction experiments channel geometries of both SBMOF-1 and SBMOF-2 provide multiple adsorption sites for hydrocarbon molecules trough C-H…π and C-H…O interactions, similarly to interactions in the molecular and protein crystals. Both materials selectively adsorb C2 hydrocarbon gases over methane as determined with IAST and breakthrough calculations, with C2H6/CH4 selectivity as high as 74 in SBMOF-1.

  14. Lithium inclusion in indium metal-organic frameworks showing increased surface area and hydrogen adsorption

    Directory of Open Access Journals (Sweden)

    Mathieu Bosch

    2014-12-01

    Full Text Available Investigation of counterion exchange in two anionic In-Metal-Organic Frameworks (In-MOFs showed that partial replacement of disordered ammonium cations was achieved through the pre-synthetic addition of LiOH to the reaction mixture. This resulted in a surface area increase of over 1600% in {Li [In(1,3 − BDC2]}n and enhancement of the H2 uptake of approximately 275% at 80 000 Pa at 77 K. This method resulted in frameworks with permanent lithium content after repeated solvent exchange as confirmed by inductively coupled plasma mass spectrometry. Lithium counterion replacement appears to increase porosity after activation through replacement of bulkier, softer counterions and demonstrates tuning of pore size and properties in MOFs.

  15. Metal-Organic Frameworks for Resonant-Gravimetric Detection of Trace-Level Xylene Molecules.

    Science.gov (United States)

    Xu, Tao; Xu, Pengcheng; Zheng, Dan; Yu, Haitao; Li, Xinxin

    2016-12-20

    As one of typical VOCs, xylene is seriously harmful to human health. Nowadays, however, there is really lack of portable sensing method to directly detect environmental xylene that has chemical inertness. Especially when the concentration of xylene is lower than the human olfactory threshold of 470 ppb, people are indeed hard to be aware of and avoid this harmful vapor. Herein the metal-organic framework (MOF) of HKUST-1 is first explored for sensing to the nonpolar molecule of p-xylene. And the sensing mechanism is identified that is via host-guest interaction of MOF with xylene molecule. By loading MOFs on mass-gravimetric resonant-cantilevers, sensing experiments for four MOFs of MOF-5, HKUST-1, ZIF-8, and MOF-177 approve that HKUST-1 has the highest sensitivity to p-xylene. The resonant-gravimetric sensing experiments with our HKUST-1 based sensors have demonstrated that trace-level p-xylene of 400 ppb can be detected that is lower than the human olfactory threshold of 470 ppb. We analyze that the specificity of HKUST-1 to xylene comes from Cu 2+ -induced moderate Lewis acidity and the "like dissolves like" interaction of the benzene ring. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is used to elucidate the adsorbing/sensing mechanism of HKUST-1 to p-xylene, where p-xylene adsorbing induced blue-shift phenomenon is observed that confirms the sensing mechanism. Our study also indicates that the sensor shows good selectivity to various kinds of common interfering gases. And the long-term repeatability and stability of the sensing material are also approved for the usage/storage period of two months. This research approves that the MOF materials exhibit potential usages for high performance chemical sensors applications.

  16. Understanding Volumetric and Gravimetric Hydrogen Adsorption Trade-off in Metal-Organic Frameworks.

    Science.gov (United States)

    Gómez-Gualdrón, Diego A; Wang, Timothy C; García-Holley, Paula; Sawelewa, Ruth M; Argueta, Edwin; Snurr, Randall Q; Hupp, Joseph T; Yildirim, Taner; Farha, Omar K

    2017-10-04

    Metal-organic frameworks (MOFs) are porous crystalline materials that are promising for adsorption-based, on-board storage of hydrogen in fuel-cell vehicles. Volumetric and gravimetric hydrogen capacities are the key factors that determine the size and weight of the MOF-filled tank required to store a certain amount of hydrogen for reasonable driving range. Therefore, they must be optimized so the tank is neither too large nor too heavy. Because the goals of maximizing MOF volumetric and gravimetric hydrogen adsorption loadings individually are incompatible, an in-depth understanding of the trade-off between MOF volumetric and gravimetric loadings is necessary to achieve the best compromise between these properties. Here we study, both experimentally and computationally, the trade-off between volumetric and gravimetric cryo-adsorbed hydrogen deliverable capacity by taking an isoreticular series of highly stable zirconium MOFs, NU-1101, NU-1102, and NU-1103 as a case study. These MOFs were studied under recently proposed operating conditions: 77 K/100 bar →160 K/5 bar. We found the difference between highest and lowest measured deliverable capacity in the MOF series to be ca. 40% gravimetrically, but only ca. 10% volumetrically. From our molecular simulation results, we found hydrogen "monolayer" adsorption to be proportional to the surface area, whereas hydrogen "pore filling" adsorption is proportional to the pore volume. Thus, we found that the higher variability in gravimetric deliverable capacity in contrast to the volumetric capacity, occurs due to the proportional relation between gravimetric surface area and pore volume in the NU-110x series in contrast to the inverse relation between volumetric surface area and void fraction. Additionally, we find better correlations with geometric surface areas than with BET areas. NU-1101 presents the highest measured volumetric performance with 46.6 g/L (9.1 wt %), whereas NU-1103 presents the highest gravimetric one

  17. Stress-induced chemical detection using flexible metal-organic frameworks.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Hesketh, Peter J. (Georgia Institute of Technology, Atlanta, GA); Gall, Kenneth A. (Georgia Institute of Technology, Atlanta, GA); Choudhury, A. (Georgia Institute of Technology, Atlanta, GA); Pikarsky, J. (Georgia Institute of Technology, Atlanta, GA); Andruszkiewicz, Leanne (Georgia Institute of Technology, Atlanta, GA); Houk, Ronald J. T.; Talin, Albert Alec (National Institute of Standards & Technology, Gaithersburg, MD)

    2009-09-01

    In this work we demonstrate the concept of stress-induced chemical detection using metal-organic frameworks (MOFs) by integrating a thin film of the MOF HKUST-1 with a microcantilever surface. The results show that the energy of molecular adsorption, which causes slight distortions in the MOF crystal structure, can be efficiently converted to mechanical energy to create a highly responsive, reversible, and selective sensor. This sensor responds to water, methanol, and ethanol vapors, but yields no response to either N{sub 2} or O{sub 2}. The magnitude of the signal, which is measured by a built-in piezoresistor, is correlated with the concentration and can be fitted to a Langmuir isotherm. Furthermore, we show that the hydration state of the MOF layer can be used to impart selectivity to CO{sub 2}. We also report the first use of surface-enhanced Raman spectroscopy to characterize the structure of a MOF film. We conclude that the synthetic versatility of these nanoporous materials holds great promise for creating recognition chemistries to enable selective detection of a wide range of analytes. A force field model is described that successfully predicts changes in MOF properties and the uptake of gases. This model is used to predict adsorption isotherms for a number of representative compounds, including explosives, nerve agents, volatile organic compounds, and polyaromatic hydrocarbons. The results show that, as a result of relatively large heats of adsorption (> 20 kcal mol{sup -1}) in most cases, we expect an onset of adsorption by MOF as low as 10{sup -6} kPa, suggesting the potential to detect compounds such as RDX at levels as low as 10 ppb at atmospheric pressure.

  18. High-Throughput Computational Screening of the Metal Organic Framework Database for CH4/H2 Separations.

    Science.gov (United States)

    Altintas, Cigdem; Erucar, Ilknur; Keskin, Seda

    2018-01-31

    Metal organic frameworks (MOFs) have been considered as one of the most exciting porous materials discovered in the last decade. Large surface areas, high pore volumes, and tailorable pore sizes make MOFs highly promising in a variety of applications, mainly in gas separations. The number of MOFs has been increasing very rapidly, and experimental identification of materials exhibiting high gas separation potential is simply impractical. High-throughput computational screening studies in which thousands of MOFs are evaluated to identify the best candidates for target gas separation is crucial in directing experimental efforts to the most useful materials. In this work, we used molecular simulations to screen the most complete and recent collection of MOFs from the Cambridge Structural Database to unlock their CH 4 /H 2 separation performances. This is the first study in the literature, which examines the potential of all existing MOFs for adsorption-based CH 4 /H 2 separation. MOFs (4350) were ranked based on several adsorbent evaluation metrics including selectivity, working capacity, adsorbent performance score, sorbent selection parameter, and regenerability. A large number of MOFs were identified to have extraordinarily large CH 4 /H 2 selectivities compared to traditional adsorbents such as zeolites and activated carbons. We examined the relations between structural properties of MOFs such as pore sizes, porosities, and surface areas and their selectivities. Correlations between the heat of adsorption, adsorbility, metal type of MOFs, and selectivities were also studied. On the basis of these relations, a simple mathematical model that can predict the CH 4 /H 2 selectivity of MOFs was suggested, which will be very useful in guiding the design and development of new MOFs with extraordinarily high CH 4 /H 2 separation performances.

  19. Shape- and morphology-controlled sustainable synthesis of Cu, Co, and in metal organic frameworks with high CO2 capture capacity

    KAUST Repository

    Sarawade, Pradip

    2012-11-06

    We studied the effects of various surfactants on the shape and morphology of three metal organic frameworks (MOFs), i.e., Co-MOF, Cu-MOF, and In-MOF, which were synthesized under microwave irradiation. The as-synthesized materials were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and nitrogen sorption. The effects of microwave irradiation time, temperature, and surfactant template were investigated. The synthetic parameters, including the type of surfactant template and the reaction temperature, played crucial roles in the size, shape, and morphology of the MOF microcrystals. We also evaluated these MOFs as sorbents for capturing CO2. Of the synthesized materials, Cu-MOF demonstrated the highest CO2 capture capacity, even at atmospheric pressure and ambient temperature. © 2012 American Chemical Society.

  20. Homochiral metal-organic frameworks and their application in chromatography enantioseparations.

    Science.gov (United States)

    Peluso, Paola; Mamane, Victor; Cossu, Sergio

    2014-10-10

    The last frontier in the chiral stationary phases (CSPs) field for chromatography enantioseparations is represented by homochiral metal-organic frameworks (MOFs), a class of organic-inorganic hybrid materials built from metal-connecting nodes and organic-bridging ligands. The modular nature of these materials allows to design focused structures by combining properly metal, organic ligands and rigid polytopic spacers. Intriguingly, chiral ligands introduce molecular chirality in the MOF-network as well as homochirality in the secondary structure of materials (such as homohelicity) producing homochiral nets in a manner mimicking biopolymers (proteins, polysaccharides) which are characterized by a definite helical sense associated with the chirality of their building blocks (amino acids or sugars). Nowadays, robust and flexible materials characterized by high porosity and surface area became available by using preparative procedures typical of the so-called reticular synthesis. This review focuses on recent developments in the synthesis and applications of homochiral MOFs as supports for chromatography enantioseparations. Indeed, despite this field is in its infancy, interesting results have been produced and a critical overview of the 12 reported applications for gas chromatography (GC) and high-performance liquid chromatography (HPLC) can orient the reader approaching the field. Mechanistic aspects are shortly discussed and a view regarding future trends in this field is provided. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Crystal conversion between metal-organic frameworks with different crystal topologies for efficient crystal design on two-dimensional substrates

    Science.gov (United States)

    Tsuruoka, Takaaki; Inoue, Kohei; Miyanaga, Ayumi; Tobiishi, Kaho; Ohhashi, Takashi; Hata, Manami; Takashima, Yohei; Akamatsu, Kensuke

    2018-04-01

    Crystal conversion of metal-organic frameworks (MOFs) between different crystal topologies on a polymer substrate has been successfully achieved by localized dissolution of MOF crystals followed by a rapid self-assembly of framework components. Upon addition of the desired organic linkers to the reaction system containing MOF crystals on the substrate, reversible crystal conversion between the [Cu2(btc)3]n and [Cu2(ndc)2(dabco)]n frameworks (btc = 1,3,5-benzene tricarboxylate, ndc = 1,4-naphthalene dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]octane) could be routinely achieved in high yields. Most surprisingly, in the case of conversion from the [Cu2(ndc)2(dabco)]n to [Cu2(btc)3]n frameworks, the [Cu2(btc)3]n crystals with unique shapes (cuboctahedron and truncated cube) could be prepared using butanol as a reaction medium.

  2. In silico discovery of metal-organic frameworks for precombustion CO2 capture using a genetic algorithm.

    Science.gov (United States)

    Chung, Yongchul G; Gómez-Gualdrón, Diego A; Li, Peng; Leperi, Karson T; Deria, Pravas; Zhang, Hongda; Vermeulen, Nicolaas A; Stoddart, J Fraser; You, Fengqi; Hupp, Joseph T; Farha, Omar K; Snurr, Randall Q

    2016-10-01

    Discovery of new adsorbent materials with a high CO 2 working capacity could help reduce CO 2 emissions from newly commissioned power plants using precombustion carbon capture. High-throughput computational screening efforts can accelerate the discovery of new adsorbents but sometimes require significant computational resources to explore the large space of possible materials. We report the in silico discovery of high-performing adsorbents for precombustion CO 2 capture by applying a genetic algorithm to efficiently search a large database of metal-organic frameworks (MOFs) for top candidates. High-performing MOFs identified from the in silico search were synthesized and activated and show a high CO 2 working capacity and a high CO 2 /H 2 selectivity. One of the synthesized MOFs shows a higher CO 2 working capacity than any MOF reported in the literature under the operating conditions investigated here.

  3. A systematic study on the use of ultrasound energy for the synthesis of nickel-metal organic framework compounds.

    Science.gov (United States)

    Sargazi, G; Afzali, D; Daldosso, N; Kazemian, H; Chauhan, N P S; Sadeghian, Z; Tajerian, T; Ghafarinazari, A; Mozafari, M

    2015-11-01

    A nickel metal-organic framework (Ni-MOF) was successfully synthesized using ultrasound irradiation. Further to this, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and nitrogen adsorption [i.e. Brunauer-Emmett-Teller (BET) Surface Area Analysis] techniques were used to characterize the synthesized Ni-MOF. In addition, the effect of sonication on the surface area, pore diameter and pore volume of the final product was systematically studied using Taguchi technique. The experiments ascertained that manufacturing of the Ni-MOF by means of the ultrasonic-assisted technique is feasible at a relatively shorter time compare to the conventional methods. The final product showed more uniform shape distribution and improved BET properties. The obtained results offered that the synthesized Ni-MOF samples could be used in several applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Separation of C2 hydrocarbons from methane in a microporous metal-organic framework

    Science.gov (United States)

    Tang, Fu-Shun; Lin, Rui-Biao; Lin, Rong-Guang; Zhao, John Cong-Gui; Chen, Banglin

    2018-02-01

    The recovery of C2 hydrocarbons including acetylene, ethylene and ethane is challenging but important for natural gas upgrading. The separation of C2 hydrocarbons over methane was demonstrated here by using a microporous metal-organic framework [Zn3(OH)2(SDB)2] (H2SDB = 4,4'-sulfonyldibenzoic acid) consisting narrow one-dimensional pore channels. Gas sorption experiments revealed that this MOF material showed considerable uptake capacity for C2H2, C2H4 and C2H6 under ambient conditions, while its capacity for CH4 was very low. High selectivity from IAST calculations for C2H2/CH4, C2H4/CH4 and C2H6/CH4 binary mixtures demonstrated that this MOF material were promising for efficiently separating important separation of C2 hydrocarbons from methane in natural gas processing.

  5. Exceptional CO2 working capacity in a heterodiamine-grafted metal-organic framework.

    Science.gov (United States)

    Lee, Woo Ram; Jo, Hyuna; Yang, Li-Ming; Lee, Hanyeong; Ryu, Dae Won; Lim, Kwang Soo; Song, Jeong Hwa; Min, Da Young; Han, Sang Soo; Seo, Jeong Gil; Park, Yong Ki; Moon, Dohyun; Hong, Chang Seop

    2015-07-15

    An amine-functionalized metal-organic framework (MOF), dmen-Mg 2 (dobpdc) (dmen = N , N -dimethylethylenediamine), which contains a heterodiamine with both primary and tertiary amines, was prepared via a post-synthetic method. This material exhibits a significant selectivity factor for CO 2 over N 2 that is commensurate with top-performing MOFs. It is remarkable that the solid is fully regenerated under vacuum or flowing Ar at low desorption temperatures, and following this can take up CO 2 at more than 13 wt%. An exceptionally high working capacity is achieved at low regeneration temperatures and after exposure to humid conditions, which are important parameters for a real post-combustion CO 2 capture process.

  6. Gas storage in porous metal-organic frameworks for clean energy applications.

    Science.gov (United States)

    Ma, Shengqian; Zhou, Hong-Cai

    2010-01-07

    Depletion of fossil oil deposits and the escalating threat of global warming have put clean energy research, which includes the search for clean energy carriers such as hydrogen and methane as well as the reduction of carbon dioxide emissions, on the urgent agenda. A significant technical challenge has been recognized as the development of a viable method to efficiently trap hydrogen, methane and carbon dioxide gas molecules in a confined space for various applications. This issue can be addressed by employing highly porous materials as storage media, and porous metal-organic frameworks (MOFs) which have exceptionally high surface areas as well as chemically-tunable structures are playing an unusual role in this respect. In this feature article we provide an overview of the current status of clean energy applications of porous MOFs, including hydrogen storage, methane storage and carbon dioxide capture.

  7. Adsorption of silver nanoparticles from aqueous solution on copper-based metal organic frameworks (HKUST-1).

    Science.gov (United States)

    Conde-González, J E; Peña-Méndez, E M; Rybáková, S; Pasán, J; Ruiz-Pérez, C; Havel, J

    2016-05-01

    Silver nanoparticles (AgNP) are emerging pollutants. The use of novel materials such as Cu-(benzene 1,3,5-tricarboxylate, BTC) Metal-Organic Framework (MOFs), for AgNP adsorption and their removal from aqueous solutions has been studied. The effect of different parameters was followed and isotherm model was suggested. MOFs adsorbed fast and efficiently AgNP in the range C0 < 10 mg L(-1), being Freundlich isotherm (R = 0.993) these data fitted to. Among studied parameters a remarkable effect of chloride on sorption was found, thus their possible interactions were considered. The high adsorption efficiency of AgNP was achieved and it was found to be very fast. The feasibility of adsorption on Cu-(BTC) was proved in spiked waters. The results showed the potential interest of new material as adsorbent for removing AgNP from environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Improved synthesis and hydrogen storage of a microporous metal-organic framework material

    International Nuclear Information System (INIS)

    Cheng Shaojuan; Liu Shaobing; Zhao Qiang; Li Jinping

    2009-01-01

    A microporous metal-organic framework MOF-5 [Zn 4 O(BDC) 3 , BDC = 1,4-benzenedicarboxylic] was synthesized with and without H 2 O 2 by improved methods based on the previous studies. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy and nitrogen adsorption, and their hydrogen storage capacities were measured. The synthesis experiments showed that H 2 O 2 favored the growth of high quality sample, large pore volume and high specific surface area. The measurements of hydrogen storage indicated that the sample with higher specific surface area and large pore volume showed better hydrogen storage behavior than other samples. It was suggested that specific surface area and pore volume influenced the capacity of hydrogen storage for MOF-5 material.

  9. A Stable Metal-Organic Framework Featuring a Local Buffer Environment for Carbon Dioxide Fixation.

    Science.gov (United States)

    He, Hongming; Sun, Qi; Gao, Wenyang; Perman, Jason A; Sun, Fuxing; Zhu, Guangshan; Aguila, Briana; Forrest, Katherine; Space, Brian; Ma, Shengqian

    2018-04-16

    A majority of metal-organic frameworks (MOFs) fail to preserve their physical and chemical properties after exposure to acidic, neutral, or alkaline aqueous solutions, therefore limiting their practical applications in many areas. The strategy demonstrated herein is the design and synthesis of an organic ligand that behaves as a buffer to drastically boost the aqueous stability of a porous MOF (JUC-1000), which maintains its structural integrity at low and high pH values. The local buffer environment resulting from the weak acid-base pairs of the custom-designed organic ligand also greatly facilitates the performance of JUC-1000 in the chemical fixation of carbon dioxide under ambient conditions, outperforming a series of benchmark catalysts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Diffusion of Vitamin B12 Across a Mesoporous Metal Organic Framework

    Directory of Open Access Journals (Sweden)

    Veronica Valencia

    2013-01-01

    Full Text Available We measure the rate of uptake and the rate of release of a Vitamin B12 solution (dissolved in water at 2 different temperatures (room temperature and 37°C by the mesoporous metal organic framework TbMOF-100 at 1-hour intervals using a spectrophotometer. Using the Beer-Lambert law, we calculate the concentration of the stock solution based on the absorbance values obtained with the spectrophotometer. These values allow for the quantification of the initial rate of uptake and the rate of uptake at a random incubation time of the Vitamin B12 by the TbMOF-100. We also calculate the value of the coefficient of diffusion for this 2-phase system using Fick’s laws of diffusion.

  11. Sinter-Resistant Platinum Catalyst Supported by Metal-Organic Framework

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Soo [Materials Science Division, Argonne National Lab, 9700 S Cass Ave. Argonne IL 60439 USA; Nanophotonics Center, Korea Institute of Science and Technology, Seoul 02792 South Korea; Li, Zhanyong [Department of Chemistry, Northwestern University, 2145 Sheridan Rd. Evanston IL 60208 USA; Zheng, Jian [Institute for Integrated Catalysis, Pacific Northwest National Lab, P.O. Box 999 Richland WA 99352 USA; Platero-Prats, Ana E. [X-ray Science Division, Argonne National Lab, 9700 S Cass Ave. Argonne IL 60439 USA; Mavrandonakis, Andreas [Department of Chemistry, University of Minnesota, 207 Pleasant St. SE Minneapolis MN 55455 USA; Pellizzeri, Steven [Chemical and Biomolecular Engineering, Clemson University, 205 Earle Hall Clemson SC 29634 USA; Ferrandon, Magali [Chemical Sciences and Engineering Division, Argonne National Lab, 9700 S. Cass Ave. Argonne IL 60439 USA; Vjunov, Aleksei [Institute for Integrated Catalysis, Pacific Northwest National Lab, P.O. Box 999 Richland WA 99352 USA; Gallington, Leighanne C. [X-ray Science Division, Argonne National Lab, 9700 S Cass Ave. Argonne IL 60439 USA; Webber, Thomas E. [Department of Chemistry, University of Minnesota, 207 Pleasant St. SE Minneapolis MN 55455 USA; Vermeulen, Nicolaas A. [Department of Chemistry, Northwestern University, 2145 Sheridan Rd. Evanston IL 60208 USA; Penn, R. Lee [Department of Chemistry, University of Minnesota, 207 Pleasant St. SE Minneapolis MN 55455 USA; Getman, Rachel B. [Chemical and Biomolecular Engineering, Clemson University, 205 Earle Hall Clemson SC 29634 USA; Cramer, Christopher J. [Department of Chemistry, University of Minnesota, 207 Pleasant St. SE Minneapolis MN 55455 USA; Chapman, Karena W. [X-ray Science Division, Argonne National Lab, 9700 S Cass Ave. Argonne IL 60439 USA; Camaioni, Donald M. [Institute for Integrated Catalysis, Pacific Northwest National Lab, P.O. Box 999 Richland WA 99352 USA; Fulton, John L. [Institute for Integrated Catalysis, Pacific Northwest National Lab, P.O. Box 999 Richland WA 99352 USA; Lercher, Johannes A. [Institute for Integrated Catalysis, Pacific Northwest National Lab, P.O. Box 999 Richland WA 99352 USA; Department of Chemistry and Catalysis Research Institute, Technische Universität München, Lichtenbergstrasse 4 85748 Garching Germany; Farha, Omar K. [Department of Chemistry, Northwestern University, 2145 Sheridan Rd. Evanston IL 60208 USA; Hupp, Joseph T. [Materials Science Division, Argonne National Lab, 9700 S Cass Ave. Argonne IL 60439 USA; Department of Chemistry, Northwestern University, 2145 Sheridan Rd. Evanston IL 60208 USA; Martinson, Alex B. F. [Materials Science Division, Argonne National Lab, 9700 S Cass Ave. Argonne IL 60439 USA

    2018-01-02

    Installed on the zirconia nodes of a metal-organic framework (MOF) NU-1000 via targeted vapor-phase synthesis. The catalytic Pt clusters, site-isolated by organic linkers, are shown to exhibit high catalytic activity for ethylene hydrogenation while exhibiting resistance to sintering up to 200 degrees C. In situ IR spectroscopy reveals the presence of both single atoms and few-atom clusters that depend upon synthesis conditions. Operando X-ray absorption spectroscopy and Xray pair distribution analyses reveal unique changes in chemical bonding environment and cluster size stability while on stream. Density functional theory calculations elucidate a favorable reaction pathway for ethylene hydrogenation with the novel catalyst. These results provide evidence that atomic layer deposition (ALD) in MOFs is a versatile approach to the rational synthesis of size-selected clusters, including noble metals, on a high surface area support.

  12. Applications of Immobilized Bio-Catalyst in Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2018-04-01

    Full Text Available Immobilization of bio-catalysts in solid porous materials has attracted much attention in the last few decades due to its vast application potential in ex vivo catalysis. Despite the high efficiency and selectivity of enzymatic catalytic processes, enzymes may suffer from denaturation under industrial production conditions, which, in turn, diminish their catalytic performances and long-term recyclability. Metal-organic frameworks (MOFs, as a growing type of hybrid materials, have been identified as promising platforms for enzyme immobilization owing to their enormous structural and functional tunability, and extraordinary porosity. This review mainly focuses on the applications of enzyme@MOFs hybrid materials in catalysis, sensing, and detection. The improvements of catalytic activity and robustness of encapsulated enzymes over the free counterpart are discussed in detail.

  13. Zirconium-based metal organic frameworks: Highly selective adsorbents for removal of phosphate from water and urine

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Kun-Yi Andrew, E-mail: linky@nchu.edu.tw [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (China); Chen, Shen-Yi [Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (China); Jochems, Andrew P. [New Mexico Bureau of Geology & Mineral Resources and New Mexico Institute of Mining & Technology, Socorro, NM (United States)

    2015-06-15

    Phosphate is one of the most concerning compounds in wastewater streams and a main nutrient that causes eutrophication. To eliminate the phosphate pollution, Metal Organic Frameworks (MOFs) are proposed in this study as adsorbents to remove phosphate from water. The zirconium-based MOF, UiO-66, was selected as representative MOF given its exceptional stability in water. To investigate the effect of an amine functional group, UiO-66-NH2 was also prepared using an amine-substituted ligand. The adsorption kinetics and isotherm reveal that UiO-66-NH2 exhibited higher adsorption capacities than UiO-66 possibly due to the amine group. However, the interaction between phosphate and zirconium sites of UiO MOFs might be the primary factor accounting for the phosphate adsorption to UiO MOFs. UiO MOFs also exhibited a high selectivity towards phosphate over other anions such as bromate, nitrite and nitrate. Furthermore, UiO MOFs were found to adsorb phosphate and to completely remove diluted phosphate in urine. We also found that UiO MOFs could be easily regenerated and re-used for phosphate adsorption. These findings suggest that UiO MOFs can be effective and selective adsorbents to remove phosphate from water as well as urine. - Highlights: • UiO-66 as the first type of MOFs was used to remove phosphate from water and urine. • The amine group in UiO MOFs was found to enhance the phosphate adsorption. • UiO-66 exhibited a high adsorption selectivity towards phosphate over other anions. • UiO-66 could be easily regenerated and re-used with 85% regeneration efficiency.

  14. Photoreactivity of Metal-Organic Frameworks in Aqueous Solutions: Metal Dependence of Reactive Oxygen Species Production.

    Science.gov (United States)

    Liu, Kai; Gao, Yanxin; Liu, Jing; Wen, Yifan; Zhao, Yingcan; Zhang, Kunyang; Yu, Gang

    2016-04-05

    Promising applications of metal-organic frameworks (MOFs) in various fields have raised concern over their environmental fate and safety upon inevitable discharge into aqueous environments. Currently, no information regarding the transformation processes of MOFs is available. Due to the presence of repetitive π-bond structure and semiconductive property, photochemical transformations are an important fate process that affects the performance of MOFs in practical applications. In the current study, the generation of reactive oxygen species (ROS) in isoreticular MIL-53s was studied. Scavengers were employed to probe the production of (1)O2, O2(•-), and •OH, respectively. In general, MIL-53(Cr) and MIL-53(Fe) are dominated by type I and II photosensitization reactions, respectively, and MIL-53(Al) appears to be less photoreactive. The generation of ROS in MIL-53(Fe) may be underestimated due to dismutation. Further investigation of MIL-53(Fe) encapsulated diclofenac transformation revealed that diclofenac can be easily transformed by MIL-53(Fe) generated ROS. However, the cytotoxicity results implied that the ROS generated from MIL-53s have little effect on the viability of the human hepatocyte (HepG2) cell line. These results suggest that the photogeneration of ROS by MOFs may be metal-node dependent, and the application of MIL-53s as drug carriers needs to be carefully considered due to their high photoreactivity.

  15. Deciphering the Structural Relationships of Five Cd-Based Metal-Organic Frameworks.

    Science.gov (United States)

    Yuan, Feng-Ling; Yuan, Yan-Qiu; Chao, Meng-Yao; Young, David J; Zhang, Wen-Hua; Lang, Jian-Ping

    2017-06-05

    The one-pot reaction of Cd(NO 3 ) 2 ·4H 2 O and 5-(6-(hydroxymethyl)pyridin-3-yl)isophthalic acid (H 2 L) in DMF/H 2 O (DMF = N,N-dimethylformamide) produced a two-dimensional (2D) metal-organic framework (MOF) of [Cd(L)(H 2 O) 2 ] (A) bearing aqua-bridged Cd centers, accompanied by two three-dimensional (3D) MOFs [Cd(L)(DMF) 0.5 ] (B) and [Cd(L)] (C). Removing the bridging aqua molecules of A by heating led to the formation of an additional 3D MOF of [Cd(L)] (D) in a single-crystal to single-crystal (SCSC) manner. The search for the preceding compound that could convert to A resulted in the isolation of a 2D MOF [Cd(L)(DMF)] (E) that readily converted to A in water, but with the loss of single crystallinity. Upon excitation at 350 nm, A, D, E, and the ligand H 2 L fluoresced at 460 nm, 468 nm, 475 nm, and 411 nm, respectively. The fluorescence of A could be used for the selective detection of Fe 3+ in water down to 0.58 ppm. This quenching was not affected by the presence of other common metal ions.

  16. A fine-tuned Metal-Organic Framework for Autonomous Indoor Moisture Control .

    KAUST Repository

    Abdul Halim, Racha Ghassan

    2017-06-29

    Conventional adsorbents, namely zeolites and silica gel, are often used to control humidity by adsorbing water; however, adsorbents capable of dual functionality of humidification and dehumidification, offering the desired control of the moisture level at room temperature, has yet to be explored. Here we report Y-shp-MOF-5, a hybrid microporous highly-connected Rare-Earth based metal-organic framework (MOF), with dual functionality for moisture control within the recommended range of relative humidity (45% to 65% RH) set by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). Y-shp-MOF-5 exhibits exceptional structural integrity, robustness and unique humidity-control performance as confirmed by the large number (thousand) of conducted water vapor adsorption-desorption cycles. The retained structural integrity and the mechanism of water sorption were corroborated using in situ single crystal X-ray diffraction (SCXRD) studies. The resultant working water uptake of 0.45 g.g-1 is solely regulated by a simple adjustment of the relative humidity, positioning this hydrolytically stable MOF as a prospective adsorbent for humidity control in confined spaces such as space shuttles, aircraft cabins and air-conditioned buildings.

  17. Catalytic Transfer Hydrogenation of Biomass-Derived Carbonyls over Hafnium-Based Metal-Organic Frameworks.

    Science.gov (United States)

    Rojas-Buzo, Sergio; García-García, Pilar; Corma, Avelino

    2018-01-23

    A series of highly crystalline, porous, hafnium-based metal-organic frameworks (Hf-MOFs) have been shown to catalyze the transfer hydrogenation reaction of levulinic ester to produce γ-valerolactone by using isopropanol as a hydrogen donor. The results are compared with their zirconium-based counterparts. The role of the metal center in Hf-MOFs has been identified and reaction parameters optimized. NMR studies using isotopically labeled isopropanol provide evidence that the transfer hydrogenation occurs through a direct intermolecular hydrogen transfer route. The catalyst, Hf-MOF-808, can be recycled several times with only a minor decrease in catalytic activity. The generality of the procedure has been demonstrated by accomplishing the transformation with aldehydes, ketones, and α,β-unsaturated carbonyl compounds. The combination of Hf-MOF-808 with the Brønsted-acidic Al-Beta zeolite gives the four-step one-pot transformation of furfural to γ-valerolactone in good yield of 75 %. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Separation of bioactive chamazulene from chamomile extract using metal-organic framework.

    Science.gov (United States)

    Abdelhameed, Reda M; Abdel-Gawad, Hassan; Taha, Mohamed; Hegazi, Bahira

    2017-11-30

    Isolation of bioactive compounds from extracts of pharmaceutical plant is very important. In this work, copper benzene-1,3,5-tricarboxylate metal organic framework (Cu-BTC MOF) has been synthesized. It is used in separating of chamazulene from chamomile extract. The Cu-BTC MOF not only shows good chamazulene adsorption but also maintains good desorption properties. However, the research on this field is still new and the maturation of novel MOFs or the enhancements of known ones are required.The chamomile extract obtained after each stage of the treatments was carefully characterized by thin-layer chromatography (TLC), Fourier-transform infrared spectroscopy (FTIR), UV-vis spectrometry and gas chromatography-mass spectrometry (GC-MS). The morphology and the crystallinity of Cu-BTC MOF were investigated using scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD), respectively. Breakthrough experiments in a column was investigated and the data was fitted with Bohart-Adams model. Monte Carlo simulation was conducted to investigate the preferential adsorption sites of Cu-BTC for chamazulene molecules. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Bifunctional Porphyrin-Based Nano-Metal-Organic Frameworks: Catalytic and Chemosensing Studies.

    Science.gov (United States)

    Pereira, Carla F; Figueira, Flávio; Mendes, Ricardo F; Rocha, João; Hupp, Joseph T; Farha, Omar K; Simões, Mário M Q; Tomé, João P C; Paz, Filipe A Almeida

    2018-03-13

    The use of 5,10,15,20-tetrakis( p-phenylphosphonic acid)porphyrin (H 10 TPPA) as a linker in the preparation of porphyrin-based metal-organic frameworks (Por-MOFs) through coordination to lanthanides cations is reported. The resulting unprecedented materials, formulated as [M(H 9 TPPA)(H 2 O) x ]Cl 2 · yH 2 O [ x + y = 7; M 3+ = La 3+ (1), Yb 3+ (2), and Y 3+ (3)], prepared using hydrothermal synthesis, were extensively characterized in the solid-state, for both their structure and thermal robustness, using a myriad of solid-state advanced techniques. Materials were evaluated as heterogeneous catalysts in the oxidation of thioanisole by H 2 O 2 and as chemosensors for detection of nitroaromatic compounds (NACs). Nano-Por-MOFs 1-3 proved to be effective as heterogeneous catalysts in the sulfoxidation of thioanisole, with Por-MOF 1 exhibiting the best catalytic performance with a conversion of thioanisole of 89% in the first cycle and with a high selectivity for the sulfoxide derivative (90%). The catalyst maintained its activity roughly constant in three consecutive runs. Por-MOFs 1-3 can be employed as chemosensors because of a measured fluorescence quenching up to 70% for nitrobenzene, 1,4-dinitrobenzene, 4-nitrophenol, and phenol, with 2,4,6-trinitrophenol exhibiting a peculiar fluorescence profile.

  20. Ultrasensitive humidity detection using metal-organic framework-coated microsensors.

    Science.gov (United States)

    Robinson, Alex L; Stavila, Vitalie; Zeitler, Todd R; White, Michael I; Thornberg, Steven M; Greathouse, Jeffery A; Allendorf, Mark D

    2012-08-21

    The use of metal-organic framework (MOF) thin films to detect water vapor across a wide concentration range is demonstrated using MOF-functionalized quartz surface acoustic wave (SAW) sensors. A range of 3-14,800 ppmv was obtained with thin films of the MOF Cu(3)(benzenetricarboxylate)(2) (Cu-BTC) deposited by an automated layer-by-layer method. Devices coated by a manual technique demonstrated sensitivity from 0.28 to 14,800 ppmv, the limit of our test system. This exceeds the sensitivity of many commercially available sensors. Cu-BTC layers were covalently bonded directly to the silicon oxide surface, allowing devices to be heated beyond 100 °C to desorb water adsorbed in the pores without decomposition, thereby regenerating the sensors. Sensor response as a function of coating thickness was evaluated, showing that the SAW sensor response is bounded by maximum and minimum layer thicknesses. Computer simulation of H(2)O uptake shows a multistep adsorption isotherm defined by initial adsorption at open Cu-sites, followed by pore-filling and finally full saturation. Modeling and experimental results are consistent. Calculated uptake values suggest an efficient adsorption of H(2)O by Cu-BTC. These results provide the first convincing evidence that MOF functionalization of compact sensing technologies such as SAW devices and microcantilevers can compete with state-of-the art devices.

  1. Two-Dimensional Metal-Organic Framework Nanosheets for Membrane-Based Gas Separation.

    Science.gov (United States)

    Peng, Yuan; Li, Yanshuo; Ban, Yujie; Yang, Weishen

    2017-08-07

    Metal-organic framework (MOF) nanosheets could serve as ideal building blocks of molecular sieve membranes owing to their structural diversity and minimized mass-transfer barrier. To date, discovery of appropriate MOF nanosheets and facile fabrication of high performance MOF nanosheet-based membranes remain as great challenges. A modified soft-physical exfoliation method was used to disintegrate a lamellar amphiprotic MOF into nanosheets with a high aspect ratio. Consequently sub-10 nm-thick ultrathin membranes were successfully prepared, and these demonstrated a remarkable H 2 /CO 2 separation performance, with a separation factor of up to 166 and H 2 permeance of up to 8×10 -7  mol m -2  s -1  Pa -1 at elevated testing temperatures owing to a well-defined size-exclusion effect. This nanosheet-based membrane holds great promise as the next generation of ultrapermeable gas separation membrane. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Electrical semiconduction modulated by light in a cobalt and naphthalene diimide metal-organic framework.

    Science.gov (United States)

    Castaldelli, Evandro; Imalka Jayawardena, K D G; Cox, David C; Clarkson, Guy J; Walton, Richard I; Le-Quang, Long; Chauvin, Jerôme; Silva, S Ravi P; Demets, Grégoire Jean-François

    2017-12-15

    Metal-organic frameworks (MOFs) have emerged as an exciting class of porous materials that can be structurally designed by choosing particular components according to desired applications. Despite the wide interest in and many potential applications of MOFs, such as in gas storage, catalysis, sensing and drug delivery, electrical semiconductivity and its control is still rare. The use and fabrication of electronic devices with MOF-based components has not been widely explored, despite significant progress of these components made in recent years. Here we report the synthesis and properties of a new highly crystalline, electrochemically active, cobalt and naphthalene diimide-based MOF that is an efficient electrical semiconductor and has a broad absorption spectrum, from 300 to 2500 nm. Its semiconductivity was determined by direct voltage bias using a four-point device, and it features a wavelength dependant photoconductive-photoresistive dual behaviour, with a very high responsivity of 2.5 × 10 5  A W -1 .

  3. Metal organic framework MIL-101(Cr) for dehydration reactions

    Indian Academy of Sciences (India)

    aration, catalysis and drug delivery.1 MOFs possess unique two or three dimensional structures formed by the self-assembly of metal ions or metal clusters. (the connectors) are bridged with polytopic organic ligands as linkers, which allows the design of spe- cific nanometer-scale framework geometries with pore structures.

  4. Computational studies of adsorption in metal organic frameworks and interaction of nanoparticles in condensed phases

    Energy Technology Data Exchange (ETDEWEB)

    Annapureddy, HVR; Motkuri, RK; Nguyen, PTM; Truong, TB; Thallapally, PK; McGrail, BP; Dang, LX

    2014-02-05

    In this review, we describe recent efforts to systematically study nano-structured metal organic frameworks (MOFs), also known as metal organic heat carriers, with particular emphasis on their application in heating and cooling processes. We used both molecular dynamics and grand canonical Monte Carlo simulation techniques to gain a molecular-level understanding of the adsorption mechanism of gases in these porous materials. We investigated the uptake of various gases such as refrigerants R12 and R143a. We also evaluated the effects of temperature and pressure on the uptake mechanism. Our computed results compared reasonably well with available measurements from experiments, thus validating our potential models and approaches. In addition, we investigated the structural, diffusive and adsorption properties of different hydrocarbons in Ni-2(dhtp). Finally, to elucidate the mechanism of nanoparticle dispersion in condensed phases, we studied the interactions among nanoparticles in various liquids, such as n-hexane, water and methanol.

  5. A stable metal-organic framework with suitable pore sizes and rich uncoordinated nitrogen atoms on the internal surface of micropores for highly efficient CO2 capture

    NARCIS (Netherlands)

    Bao, S.J.; Krishna, R.; He, Y.B.; Qin, J.S.; Su, Z.M.; Li, S.L.; Xie, W.; Du, D.Y.; He, W.W.; Zhang, S.R.; Lan, Y.Q.

    2015-01-01

    An air-stable tetrazolate-containing framework, [ZN(2)L(2)]center dot 2DMF (NENU-520, H2L = 4-(1H-tetrazole-5-yl) biphenyl-4-carboxylic acid), with uncoordinated N atoms on its internal surface was solvothermally synthesized and structurally characterized. This metal-organic framework (MOF)

  6. A rare earth-based metal-organic framework for moisture removal and control in confined spaces

    KAUST Repository

    Eddaoudi, Mohamed

    2017-04-13

    A method for preparing a metal-organic framework (MOF) comprising contacting one or more of a rare earth metal ion component with one or more of a tetratopic ligand component, sufficient to form a rare earth-based MOF for controlling moisture in an environment. A method of moisture control in an environment comprising adsorbing and/or desorbing water vapor in an environment using a MOF, the MOF including one or more of a rare earth metal ion component and one or more of a tetratopic ligand component. A method of controlling moisture in an environment comprising sensing the relative humidity in the environment comprising a MOF; and adsorbing water vapor on the MOF if the relative humidity is above a first level, sufficient to control moisture in an environment. The examples relate to a MOF created from 1,2,4,5-Tetrakis(4-carboxyphenyl )benzene (BTEB) as tetratopic ligand, 2-fluorobenzoic acid and Y(NO3)3, Tb(NO3)3 and Yb(NO3)3 as rare earth metals.

  7. DNA-Assembled Core-Satellite Upconverting-Metal-Organic Framework Nanoparticle Superstructures for Efficient Photodynamic Therapy.

    Science.gov (United States)

    He, Liangcan; Brasino, Michael; Mao, Chenchen; Cho, Suehyun; Park, Wounjhang; Goodwin, Andrew P; Cha, Jennifer N

    2017-06-01

    DNA-mediated assembly of core-satellite structures composed of Zr(IV)-based porphyrinic metal-organic framework (MOF) and NaYF 4 ,Yb,Er upconverting nanoparticles (UCNPs) for photodynamic therapy (PDT) is reported. MOF NPs generate singlet oxygen ( 1 O 2 ) upon photoirradiation with visible light without the need for additional small molecule, diffusional photosensitizers such as porphyrins. Using DNA as a templating agent, well-defined MOF-UCNP clusters are produced where UCNPs are spatially organized around a centrally located MOF NP. Under NIR irradiation, visible light emitted from the UCNPs is absorbed by the core MOF NP to produce 1 O 2 at significantly greater amounts than what can be produced from simply mixing UCNPs and MOF NPs. The MOF-UCNP core-satellite superstructures also induce strong cell cytotoxicity against cancer cells, which are further enhanced by attaching epidermal growth factor receptor targeting affibodies to the PDT clusters, highlighting their promise as theranostic photodynamic agents. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A hard X-ray study of a manganese-terpyridine catalyst in a chromium-based Metal Organic Framework

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Alexandra V. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-28

    Hydrogen produced from water splitting is a promising source of clean energy. However, a robust catalyst is necessary to carry out the water oxidation step of water splitting. In this study, the catalyst studied was [(terpy)Mn(μ-O)2Mn(terpy)]3+ (MnTD) synthesized in the Metal Organic Framework (MOF) MIL-101(Cr), and the method used for analysis was hard X-ray powder diffraction. The diffraction data was used to detect the presence of MOF in different catalytic stages, and lattice parameters were assigned to the samples containing MOF. Fourier maps were constructed with GSAS II to determine the contents of the MOF as preliminary studies suggested that MnTD may not be present. Results showed that MOF is present before catalysis occurs but disappears by the time 45 minutes of catalysis has ensued. Changes in the MOF’s lattice parameters and location of electron density in the Fourier maps suggest attractions between the MOF and catalyst that may lead to MOF degradation. Fourier maps also revealed limited, if any, amounts of MnTD, even before catalysis occurred. Molecular manganese oxide may be the source of the high rate of water oxidation catalysis in the studied system.

  9. Coordination Polymers and Metal Organic Frameworks Derived from 1,2,4-Triazole Amino Acid Linkers

    Directory of Open Access Journals (Sweden)

    Yann Garcia

    2011-10-01

    Full Text Available The perceptible appearance of biomolecules as prospective building blocks in the architecture of coordination polymers (CPs and metal-organic frameworks (MOFs are redolent of their inclusion in the synthon/tecton library of reticular chemistry. In this frame, for the first time a synthetic strategy has been established for amine derivatization in amino acids into 1,2,4-triazoles. A set of novel 1,2,4-triazole derivatized amino acids were introduced as superlative precursors in the design of 1D coordination polymers, 2D chiral helicates and 3D metal-organic frameworks. Applications associated with these compounds are diverse and include gas adsorption-porosity partitioning, soft sacrificial matrix for morphology and phase selective cadmium oxide synthesis, FeII spin crossover materials, zinc-b-lactamases inhibitors, logistics for generation of chiral/non-centrosymmetric networks; and thus led to a foundation of a new family of functional CPs and MOFs that are reviewed in this invited contribution.

  10. Encapsulation of a Nerve Agent Detoxifying Enzyme by a Mesoporous Zirconium Metal-Organic Framework Engenders Thermal and Long-Term Stability.

    Science.gov (United States)

    Li, Peng; Moon, Su-Young; Guelta, Mark A; Harvey, Steven P; Hupp, Joseph T; Farha, Omar K

    2016-07-06

    Immobilized enzymes typically have greater thermal and operational stability than their soluble form. Here we report that for the first time, a nerve agent detoxifying enzyme, organophosphorus acid anhydrolase (OPAA), has been successfully encapsulated into a water-stable zirconium metal-organic framework (MOF). This MOF features a hierarchical mesoporous channel structure and exhibits a 12 wt % loading capacity of OPAA. The thermal and long-term stabilities of OPAA are both significantly enhanced after immobilization.

  11. In situ formed Fe-N doped metal organic framework@carbon nanotubes/graphene hybrids for a rechargeable Zn-air battery.

    Science.gov (United States)

    Yang, Wenxiu; Zhang, Yelong; Liu, Xiangjian; Chen, Lulu; Jia, Jianbo

    2017-11-30

    This study presents an in situ route to produce 3D Fe-N doped metal organic framework@carbon nanotubes/graphene (Fe-MOF@CNTs-G) hybrids as efficient oxygen reduction reaction (ORR) catalysts in both basic and acidic solutions. A rechargeable zinc-air battery assembled with Fe-MOF@CNTs-G exhibits a lower charge/discharge overpotential than the commercial IrO 2 + 20% Pt/C catalyst.

  12. Water in Metal-Organic Frameworks: A Computational Study of Adsorption in Porous Materials in the Presence of Ambient Humidity

    Science.gov (United States)

    Ghosh, Pritha

    Metal-organic frameworks, or MOFs, are a class of porous crystalline materials renowned for their chemically tunable nature. In this work, molecular-level modeling is used to assess MOFs as potential adsorbents for a variety of applications where ambient humidity is present, such as toxic gas capture, nerve agent decomposition, and sensing via changes in proton conductivity. The concept of hydrophobicity in MOFs is explored from a number of angles. Classical simulation methods and quantum chemistry calculations are used to predict adsorption behavior and to shed light on experimentally observed phenomena. Hydrophobic MOFs are attractive candidates for selective gas capture under ambient conditions, and in this work hydrophobic MOFs are examined for two particular applications: ammonia capture and CO2 capture. In the first study, GCMC simulations are used to evaluate a set of three hydrophobic MOFs for ammonia capture at three humidity conditions: 0% relative humdity (RH), 36% RH, and 80% RH. In the second study, GCMC simulations predict the CO2 loading in a hydrophobic fluorinated MOF at 80% RH, which is the humidity of flue gas. In both of these studies, results demonstrate that hydrophobic MOFs are equally capable of capturing the target adsorbate under humid or dry conditions. In related work, water adsorption behavior is investigated for a fairly hydrophilic Zr MOF, and it is revealed that missing linker defects engender hydrophilicity in this framework. An ideal, defect-free version of this Zr MOF demonstrates hydrophobic behavior. Additionally, perfluoroalkane adsorption is predicted in a related material, a faujasite-type zeolite, and the results suggest the presence of co-adsorbed water molecules. MOFs with coordinated solvent molecules can be used as catalysts and novel chemical sensors. In this work, quantum chemistry calculations are used to study the interaction of a nerve agent simulant with a Zr MOF node. Results indicate that it is favorable for a

  13. Intrinsic Thermal Management Capabilities of Flexible Metal-Organic Frameworks for Carbon Dioxide Separation and Capture.

    Science.gov (United States)

    Hiraide, Shotaro; Tanaka, Hideki; Ishikawa, Narutomo; Miyahara, Minoru T

    2017-11-22

    We show that flexible metal-organic frameworks (MOFs) exhibiting "gate openings/closings" for CO 2 can intrinsically suppress the exothermic heat released by adsorption and the endothermic heat gained by desorption, both of which reduce the working capacity of CO 2 in a separation process under near-adiabatic conditions. We use the elastic layer-structured metal-organic framework-11 (ELM-11) [Cu(4,4'-bipyridine) 2 (BF 4 ) 2 ], which exhibits a two-step gate-adsorption isotherm, as a model system for flexible MOFs, and perform free energy analyses with the aid of grand canonical Monte Carlo simulations for ELM-11 structures that were determined by the Rietveld method using in situ synchrotron X-ray powder diffraction data. We demonstrate that the thermal management capabilities of ELM-11 showing the two-step gating for CO 2 at lower and higher pressures are nearly identical and quite effective (41% and 44% at 298 K, respectively). Moreover, we show that ELM-11 has an extremely high CO 2 selectivity for both CO 2 /N 2 and CO 2 /CH 4 mixtures at 298 K that, in addition to the intrinsic thermal management capability, is a crucial factor for application to carbon capture and storage (CCS). The multigate closing pressures of ELM-11 are not necessarily matched to the operating pressures used in CCS; however, our findings, and perspectives based on free energy analyses regarding modification of the host framework structure to tune the gating pressure, suggest that flexible MOFs exhibiting multigate openings/closings are promising materials for further development into systems with intrinsic thermal management mechanisms for CCS applications.

  14. Inorganic Nanoparticles/Metal Organic Framework Hybrid Membrane Reactors for Efficient Photocatalytic Conversion of CO2.

    Science.gov (United States)

    Maina, James W; Schütz, Jürg A; Grundy, Luke; Des Ligneris, Elise; Yi, Zhifeng; Kong, Lingxue; Pozo-Gonzalo, Cristina; Ionescu, Mihail; Dumée, Ludovic F

    2017-10-11

    Photocatalytic conversion of carbon dioxide (CO 2 ) to useful products has potential to address the adverse environmental impact of global warming. However, most photocatalysts used to date exhibit limited catalytic performance, due to poor CO 2 adsorption capacity, inability to efficiently generate photoexcited electrons, and/or poor transfer of the photogenerated electrons to CO 2 molecules adsorbed on the catalyst surface. The integration of inorganic semiconductor nanoparticles across metal organic framework (MOF) materials has potential to yield new hybrid materials, combining the high CO 2 adsorption capacity of MOF and the ability of the semiconductor nanoparticles to generate photoexcited electrons. Herein, controlled encapsulation of TiO 2 and Cu-TiO 2 nanoparticles within zeolitic imidazolate framework (ZIF-8) membranes was successfully accomplished, using rapid thermal deposition (RTD), and their photocatalytic efficiency toward CO 2 conversion was investigated under UV irradiation. Methanol and carbon monoxide (CO) were found to be the only products of the CO 2 reduction, with yields strongly dependent upon the content and composition of the dopant semiconductor particles. CuTiO 2 nanoparticle doped membranes exhibited the best photocatalytic performance, with 7 μg of the semiconductor nanoparticle enhancing CO yield of the pristine ZIF-8 membrane by 233%, and methanol yield by 70%. This work opens new routes for the fabrication of hybrid membranes containing inorganic nanoparticles and MOFs, with potential application not only in catalysis but also in electrochemical, separation, and sensing applications.

  15. Silver carboxylate metal-organic frameworks with highly antibacterial activity and biocompatibility.

    Science.gov (United States)

    Lu, Xinyi; Ye, Junwei; Zhang, Dekui; Xie, Ruixia; Bogale, Raji Feyisa; Sun, Yuan; Zhao, Limei; Zhao, Qi; Ning, Guiling

    2014-09-01

    Two novel Ag-based metal-organic frameworks (MOFs) [Ag2(O-IPA)(H2O)·(H3O)] (1) and [Ag5(PYDC)2(OH)] (2) were synthesized under the hydrothermal conditions using aromatic-carboxylic acids containing hydroxyl and pyridyl groups as ligands (HO-H2IPA=5-hydroxyisophthalic acid and H2PYDC=pyridine-3, 5-dicarboxylic acid). Single crystal X-ray diffraction indicated that two compounds exhibit three-dimensional frameworks constructed from different rod-shaped molecular building blocks. Both compounds favor slow release of Ag(+) ions leading to excellent and long-term antimicrobial activities towards Gram-negative bacteria, Escherichia coli (E. coli) and Gram-positive bacteria, Staphylococcus aureus (S. aureus). Their antibacterial potency was evaluated by using a minimal inhibition concentration (MIC) benchmark and an inhibition zone testing. High-resolution transmission electron microscope images indicate that the Ag-based MOFs could rupture the bacterial membrane resulting in cell death. Hematological study showed that these MOFs exhibit good biocompatibility in mice. In addition, good thermal stability and optical stability under UV-visible and visible light are beneficial for their antibacterial application. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. A Metal Chelating Porous Polymeric Support: The Missing Link for a Defect-free Metal-Organic Framework Composite Membrane

    KAUST Repository

    Barankova, Eva

    2017-02-06

    Since the discovery of size-selective metal-organic frameworks (MOFs), researchers have tried to incorporate these materials into gas separation membranes. Impressive gas selectivities were found, but these MOF membranes were mostly made on inorganic supports, which are generally too bulky and expensive for industrial gas separation. Forming MOF layers on porous polymer supports is industrially attractive but technically challenging. Two features to overcome these problems are described: 1) a metal chelating support polymer to bind the MOF layer, and 2) control of MOF crystal growth by contra-diffusion, aiming at a very thin nanocrystalline MOF layer. Using a metal chelating polythiosemicarbazide (PTSC) support and adjusting the metal and organic ligand concentrations carefully, a very compact ZIF-8 (ZIF=zeolitic imidazolate framework) layer was produced that displayed interference colors because of its smooth surface and extreme thinness-within the range of visible light. High performances were measured in terms of hydrogen/propane (8350) and propylene/propane (150) selectivity.

  17. A Metal Chelating Porous Polymeric Support: The Missing Link for a Defect-Free Metal-Organic Framework Composite Membrane.

    Science.gov (United States)

    Barankova, Eva; Tan, Xiaoyu; Villalobos, Luis Francisco; Litwiller, Eric; Peinemann, Klaus-Viktor

    2017-03-06

    Since the discovery of size-selective metal-organic frameworks (MOFs), researchers have tried to incorporate these materials into gas separation membranes. Impressive gas selectivities were found, but these MOF membranes were mostly made on inorganic supports, which are generally too bulky and expensive for industrial gas separation. Forming MOF layers on porous polymer supports is industrially attractive but technically challenging. Two features to overcome these problems are described: 1) a metal chelating support polymer to bind the MOF layer, and 2) control of MOF crystal growth by contra-diffusion, aiming at a very thin nanocrystalline MOF layer. Using a metal chelating poly-thiosemicarbazide (PTSC) support and adjusting the metal and organic ligand concentrations carefully, a very compact ZIF-8 (ZIF=zeolitic imidazolate framework) layer was produced that displayed interference colors because of its smooth surface and extreme thinness-within the range of visible light. High performances were measured in terms of hydrogen/propane (8350) and propylene/propane (150) selectivity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. The relevance of metal organic frameworks (MOFs) in inorganic ...

    Indian Academy of Sciences (India)

    The fast depletion of natural resources such as oil and gas has propelled researchers to look for alterna- tives which can be utilized as a fuel. In this respect, hydrogen evolved as the leading alternative as well as the green fuel, but the transport and handling has be- come important issues due to the combustible nature.

  19. Neutron powder diffraction of metal-organic frameworks for ...

    Indian Academy of Sciences (India)

    Abstract. We review recent structural studies that we have undertaken aimed at eluci- dating the fundamental properties of metal-organic framework materials and their inter- actions with hydrogen. We have shown that exposing coordinatively unsaturated metal centers can greatly enhance the hydrogen binding energy and ...

  20. Neutron powder diffraction of metal-organic frameworks for ...

    Indian Academy of Sciences (India)

    We review recent structural studies that we have undertaken aimed at elucidating the fundamental properties of metal-organic framework materials and their interactions with hydrogen. We have shown that exposing coordinatively unsaturated metal centers can greatly enhance the hydrogen binding energy and that they ...

  1. Supramolecular Assembly of Calcium Metal - Organic Frameworks with Structural Transformation

    Czech Academy of Sciences Publication Activity Database

    Liang, P.-Ch.; Liu, H.-K.; Yeh, Ch.-T.; Lin, Ch.-H.; Zima, Vítězslav

    2011-01-01

    Roč. 11, č. 3 (2011), 699-708 ISSN 1528-7483 R&D Projects: GA ČR GA203/08/0208 Institutional research plan: CEZ:AV0Z40500505 Keywords : metal - organic frameworks * calcium * structure Subject RIV: CA - Inorganic Chemistry Impact factor: 4.720, year: 2011

  2. Photonic metal-organic framework composite spheres: a new kind of optical material with self-reporting molecular recognition

    Science.gov (United States)

    Cui, Jiecheng; Gao, Ning; Wang, Chen; Zhu, Wei; Li, Jian; Wang, Hui; Seidel, Philipp; Ravoo, Bart Jan; Li, Guangtao

    2014-09-01

    Exploiting metal-organic framework (MOF) materials as novel building blocks to construct superstructures with extended and enhanced functions represents a big challenge. In biological systems, the ordering of many components is not achieved by interaction of the components with each other, but by interaction of each component with the host protein which provides a matrix to support the entire assembly. Inspired by biological systems, in this work, a general strategy for efficient spatial arrangement of MOF materials was developed by using spherical colloidal crystals as host matrices, affording a new class of highly tunable MOF composite spheres with a series of distinctive properties. It was found that the synergetic combination of the unique features of both MOF and photonic colloidal crystal imparted these hierarchically structured spheres intrinsic optical properties, specific molecular recognition with self-reporting signalling, derivatization capability, and anisotropy. More importantly, the unique photonic band-gap structure integrated in these composite spheres provides a more convenient means to manipulate the photophysical and photochemical behaviour of the trapped guest molecules in MOF nanocavities.Exploiting metal-organic framework (MOF) materials as novel building blocks to construct superstructures with extended and enhanced functions represents a big challenge. In biological systems, the ordering of many components is not achieved by interaction of the components with each other, but by interaction of each component with the host protein which provides a matrix to support the entire assembly. Inspired by biological systems, in this work, a general strategy for efficient spatial arrangement of MOF materials was developed by using spherical colloidal crystals as host matrices, affording a new class of highly tunable MOF composite spheres with a series of distinctive properties. It was found that the synergetic combination of the unique features of

  3. Molecular simulations of self-assembly processes in metal-organic frameworks: Model dependence

    Science.gov (United States)

    Biswal, Debasmita; Kusalik, Peter G.

    2017-07-01

    Molecular simulation is a powerful tool for investigating microscopic behavior in various chemical systems, where the use of suitable models is critical to successfully reproduce the structural and dynamic properties of the real systems of interest. In this context, molecular dynamics simulation studies of self-assembly processes in metal-organic frameworks (MOFs), a well-known class of porous materials with interesting chemical and physical properties, are relatively challenging, where a reasonably accurate representation of metal-ligand interactions is anticipated to play an important role. In the current study, we both investigate the performance of some existing models and introduce and test new models to help explore the self-assembly in an archetypal Zn-carboxylate MOF system. To this end, the behavior of six different Zn-ion models, three solvent models, and two ligand models was examined and validated against key experimental structural parameters. To explore longer time scale ordering events during MOF self-assembly via explicit solvent simulations, it is necessary to identify a suitable combination of simplified model components representing metal ions, organic ligands, and solvent molecules. It was observed that an extended cationic dummy atom (ECDA) Zn-ion model combined with an all-atom carboxylate ligand model and a simple dipolar solvent model can reproduce characteristic experimental structures for the archetypal MOF system. The successful use of these models in extensive sets of molecular simulations, which provide key insights into the self-assembly mechanism of this archetypal MOF system occurring during the early stages of this process, has been very recently reported.

  4. Lanthanide-Functionalized Metal-Organic Framework Hybrid Systems To Create Multiple Luminescent Centers for Chemical Sensing.

    Science.gov (United States)

    Yan, Bing

    2017-11-21

    Metal-organic frameworks (MOFs) possess an important advantage over other candidate classes for chemosensory materials because of their exceptional structural tunability and properties. Luminescent sensing using MOFs is a simple, intuitive, and convenient method to recognize species, but the method has limitations, such as insufficient chemical selectivity and signal loss. MOFs contain versatile building blocks (linkers or ligands) with special chemical reactivity, and postsynthetic modification (PSM) provides an opportunity to exploit and expand their unique properties. The linkers in most MOFs contain aromatic subunits that can readily display luminescence after ultraviolet or visible (typically blue) excitation, and this is the main luminescent nature of most MOFs. The introduction of photoactive lanthanide ions (Ln 3+ ) into the MOF hosts may produce new luminescent signals at different positions from that of the MOF linker, but this depends on the intramolecular energy transfer (antenna effect) from the MOF (linkers) to the Ln 3+ ions. Controlling the Ln 3+ content in MOF hybrids may create multiple luminescent centers. The nature of the unique luminescent centers may cause different responses to sensing species (i.e., ratiometric sensing), which may provide a new opportunity for luminescence research with applications to chemical sensing. In this Account, recent research progress on using lanthanide-functionalized MOF hybrid materials to create multiple luminescent centers for chemical sensing is described. Here we propose a general strategy to functionalize MOF hosts with lanthanide ions, compounds, or other luminescent species (organic dyes or carbon dots) and to assemble types of photofunctional hybrid systems based on lanthanide-functionalized MOFs. Five main methods were used to functionalize the MOFs and assemble the hybrid materials: in situ composition, ionic doping, ionic exchange, covalent PSM, and coordinated PSM. Through the lanthanide

  5. Nonlinear optical properties of Pb-La metal-organic chelidamic acid frameworks

    Science.gov (United States)

    Tan, Min; Chen, Ruiqi; Yang, Sanjun; Liu, Qiming

    2017-04-01

    Chelidamic acid, acting as ligands, reacted with metal cation of lead and lanthanum. Both of them were dissolved in water and resulted in novel MOFs complexes by using solvothermal synthesis method. The complexes were characterized by the X-ray diffraction, UV-vis spectrophotometer and Z-scan measurements to investigate their morphology and optical properties. The Z-scan measurements indicated that the obtained lead metal-organic chelidamic acid frameworks showed 6.09 × 10-12 esu of χ(3). The special structure and properties, especially the empty f-electron orbital of the rare earth elements, were used to enhance optical nonlinearity. Using one-step solvothermal synthesis method, we added lanthanum into the lead-chelidamic acid metal organic complexes. By changing the spatial configuration of the ligand in the self-assembly process, novel structural complex metals of the lead-lanthanum metal-organic chelidamic acid frameworks have been successfully synthetized, and the third-order nonlinear susceptibility of χ(3)was enhanced to be 1.13 × 10-11 esu.

  6. Flexible metal-organic framework compounds: In situ studies for selective CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    Allen, A.J., E-mail: andrew.allen@nist.gov [Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899-8520 (United States); Espinal, L.; Wong-Ng, W. [Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899-8520 (United States); Queen, W.L. [NIST Center for Neutron Research, Gaithersburg, MD 20899-6102 (United States); The Molecular Foundry, Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA 94720 (United States); Brown, C.M. [NIST Center for Neutron Research, Gaithersburg, MD 20899-6102 (United States); Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716 (United States); Kline, S.R. [NIST Center for Neutron Research, Gaithersburg, MD 20899-6102 (United States); Kauffman, K.L. [National Energy Technology Laboratory (NETL), US Department of Energy, Pittsburgh, PA 15236 (United States); Culp, J.T. [National Energy Technology Laboratory (NETL), US Department of Energy, Pittsburgh, PA 15236 (United States); URS Corporation, South Park, PA 15219 (United States); Matranga, C. [National Energy Technology Laboratory (NETL), US Department of Energy, Pittsburgh, PA 15236 (United States)

    2015-10-25

    Results are presented that explore the dynamic structural changes occurring in two highly flexible nanocrystalline metal-organic framework (MOF) compounds during the adsorption and desorption of pure gases and binary mixtures. The Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN){sub 4}] and catena-bis(dibenzoylmethanato)-(4,4′-bipyridyl)nickel(II) chosen for this study are 3-D and 1-D porous coordination polymers (PCP) with a similar gate opening pressure response for CO{sub 2} isotherms at 303 K, but with differing degrees of flexibility for structural change to accommodate guest molecules. As such, they serve as a potential model system for evaluating the complex kinetics associated with dynamic structure changes occurring in response to gas adsorption in flexible MOF systems. Insights into the crystallographic changes occurring as the MOF pore structure expands and contracts in response to interactions with CO{sub 2}, N{sub 2}, and CO{sub 2}/N{sub 2} mixtures have been obtained from in situ small-angle neutron scattering and neutron diffraction, combined with ex situ X-ray diffraction structure measurements. The role of structure in carbon capture functionality is discussed with reference to the ongoing characterization challenges and a possible materials-by-design approach. - Graphical abstract: We present in situ small-angle neutron scattering results for two flexible metal-organic frameworks (MOFs). The figure shows that for one (NiBpene, high CO{sub 2} adsorption) the intensity of the Bragg peak for the expandable d-spacing most associated with CO{sub 2} adsorption varies approximately with the isotherm, while for the other (NiDBM-Bpy, high CO{sub 2} selectivity) the d-spacing, itself, varies with the isotherm. The cartoons show the proposed modes of structural change. - Highlights: • Dynamic structures of two flexible MOF CO{sub 2} sorbent compounds are compared in situ. • These porous solid sorbents serve as models for pure & dual gas adsorption. • Different

  7. Flexible metal-organic framework compounds: In situ studies for selective CO2 capture

    International Nuclear Information System (INIS)

    Allen, A.J.; Espinal, L.; Wong-Ng, W.; Queen, W.L.; Brown, C.M.; Kline, S.R.; Kauffman, K.L.; Culp, J.T.; Matranga, C.

    2015-01-01

    Results are presented that explore the dynamic structural changes occurring in two highly flexible nanocrystalline metal-organic framework (MOF) compounds during the adsorption and desorption of pure gases and binary mixtures. The Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN) 4 ] and catena-bis(dibenzoylmethanato)-(4,4′-bipyridyl)nickel(II) chosen for this study are 3-D and 1-D porous coordination polymers (PCP) with a similar gate opening pressure response for CO 2 isotherms at 303 K, but with differing degrees of flexibility for structural change to accommodate guest molecules. As such, they serve as a potential model system for evaluating the complex kinetics associated with dynamic structure changes occurring in response to gas adsorption in flexible MOF systems. Insights into the crystallographic changes occurring as the MOF pore structure expands and contracts in response to interactions with CO 2 , N 2 , and CO 2 /N 2 mixtures have been obtained from in situ small-angle neutron scattering and neutron diffraction, combined with ex situ X-ray diffraction structure measurements. The role of structure in carbon capture functionality is discussed with reference to the ongoing characterization challenges and a possible materials-by-design approach. - Graphical abstract: We present in situ small-angle neutron scattering results for two flexible metal-organic frameworks (MOFs). The figure shows that for one (NiBpene, high CO 2 adsorption) the intensity of the Bragg peak for the expandable d-spacing most associated with CO 2 adsorption varies approximately with the isotherm, while for the other (NiDBM-Bpy, high CO 2 selectivity) the d-spacing, itself, varies with the isotherm. The cartoons show the proposed modes of structural change. - Highlights: • Dynamic structures of two flexible MOF CO 2 sorbent compounds are compared in situ. • These porous solid sorbents serve as models for pure & dual gas adsorption. • Different degrees of structural freedom give different

  8. Metal–Organic Frameworks (MOFs) as Multivalent Materials: Size Control and Surface Functionalization by Monovalent Capping Ligands

    NARCIS (Netherlands)

    Rijnaarts, Timon; Weinhart-Mejia, R.; Egberink, Richard J.M.; van Roosmalen, W.P.E.; Huskens, Jurriaan

    2015-01-01

    Control over particle size and composition are pivotal to tune the properties of metal organic frameworks (MOFs), for example, for biomedical applications. Particle-size control and functionalization of MIL-88A were achieved by using stoichiometric replacement of a small fraction of the divalent

  9. Hollow silica-copper-carbon anodes using copper metal-organic frameworks as skeletons.

    Science.gov (United States)

    Sun, Zixu; Xin, Fengxia; Cao, Can; Zhao, Chongchong; Shen, Cai; Han, Wei-Qiang

    2015-12-28

    Hollow silica-copper-carbon (H-SCC) nanocomposites are first synthesized using copper metal-organic frameworks as skeletons to form Cu-MOF@SiO(2) and then subjected to heat treatment. In the composites, the hollow structure and the void space from the collapse of the MOF skeleton can accommodate the huge volume change, buffer the mechanical stress caused by lithium ion insertion/extraction and maintain the structural integrity of the electrode and a long cycling stability. The ultrafine copper with a uniform size of around 5 nm and carbon with homogeneous distribution from the decomposition of the MOF skeleton can not only enhance the electrical conductivity of the composite and preserve the structural and interfacial stabilization, but also suppress the aggregation of silica nanoparticles and cushion the volume change. In consequence, the resulting material as an anode for lithium-ion batteries (LIBs) delivers a reversible capacity of 495 mA h g(-1) after 400 cycles at a current density of 500 mA g(-1). The synthetic method presented in this paper provides a facile and low-cost strategy for the large-scale production of hollow silica/copper/carbon nanocomposites as an anode in LIBs.

  10. Metal-organic framework polymethyl methacrylate composites for open-tubular capillary electrochromatography.

    Science.gov (United States)

    Li, Li-Man; Yang, Fang; Wang, He-Fang; Yan, Xiu-Ping

    2013-11-05

    Metal-organic frameworks (MOFs) are attractive as novel separation medium due to their distinguished properties including large surface area, accessible tunnels and diverse structures. Here, we report the incorporation of MOF CAU-1 (CAU=Christian-Albrechts-University) into polymethyl methacrylate (PMMA) to produce a new composite (CAU-1@PMMA), and the fabrication of CAU-1@PMMA coated capillary for open tubular capillary electrochromatography (CEC). CAU-1 contains unprecedented [Al8(OH)4(OCH3)8](12+) clusters connected by twelve aminoterephthalic acid linkers, and is highly porous and stable in a variety of buffer solutions. The incorporation of CAU-1 into PMMA not only increases surface area, but also electroosmotic flow (EOF). As a result, the CAU-1@PMMA coated capillary column gives higher column efficiency, larger column capacity, and shorter separation time for baseline separation of two groups of aromatic carboxylic acids than the PMMA coated capillary column. Besides, the incorporation of CAU-1 also improves the resolution for the CEC separation of basic sulfa drugs and structurally related peptides. The run-to-run, day-to-day and column-to-column precision for the EOF of CAU-1@PMMA coated capillary column is 0.3%, 0.4%, and 2.2% (relative standard deviation), respectively. The results show that MOFs composites are promising stationary phases for CEC applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Ultrafast water sensing and thermal imaging by a metal-organic framework with switchable luminescence

    Science.gov (United States)

    Chen, Ling; Ye, Jia-Wen; Wang, Hai-Ping; Pan, Mei; Yin, Shao-Yun; Wei, Zhang-Wen; Zhang, Lu-Yin; Wu, Kai; Fan, Ya-Nan; Su, Cheng-Yong

    2017-06-01

    A convenient, fast and selective water analysis method is highly desirable in industrial and detection processes. Here a robust microporous Zn-MOF (metal-organic framework, Zn(hpi2cf)(DMF)(H2O)) is assembled from a dual-emissive H2hpi2cf (5-(2-(5-fluoro-2-hydroxyphenyl)-4,5-bis(4-fluorophenyl)-1H-imidazol-1-yl)isophthalic acid) ligand that exhibits characteristic excited state intramolecular proton transfer (ESIPT). This Zn-MOF contains amphipathic micropores (manifesting an excellent example of dynamic reversible coordination behaviour. The interconversion between the hydrated and dehydrated phases can turn the ligand ESIPT process on or off, resulting in sensitive two-colour photoluminescence switching over cycles. Therefore, this Zn-MOF represents an excellent PL water-sensing material, showing a fast (on the order of seconds) and highly selective response to water on a molecular level. Furthermore, paper or in situ grown ZnO-based sensing films have been fabricated and applied in humidity sensing (RH<1%), detection of traces of water (<0.05% v/v) in various organic solvents, thermal imaging and as a thermometer.

  12. Characterization of compositional modifications in metal-organic frameworks using carbon and alpha particle microbeams

    Science.gov (United States)

    Paneta, V.; Fluch, U.; Petersson, P.; Ott, S.; Primetzhofer, D.

    2017-08-01

    Zirconium-oxide based metal-organic frameworks (MOFs) were grown on p-type Si wafers. A modified linker molecule containing iodine was introduced by post synthetic exchange (PSE). Samples have been studied using Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-ray Emission (PIXE) techniques, employing the 5 MV 15SDH-2 Pelletron Tandem accelerator at the Ångström laboratory. The degree of post synthetic uptake of the iodine-containing linker has been investigated with both a broad beam and a focused beam of carbon and alpha particles targeting different kind of MOF crystals which were of ∼1-10 μm in size, depending on the linker used. Iodine concentrations in MOF crystallites were also measured by Nuclear Magnetic Resonance Spectroscopy (NMR) and are compared to the RBS results. In parallel to the ion beam studies, samples were investigated by Scanning Electron Microscopy (SEM) to quantify possible crystallite clustering, develop optimum sample preparation routines and to characterize the potential ion beam induced sample damage and its dependence on different parameters. Based on these results the reliability and accuracy of ion beam data is assessed.

  13. Smart Resonant Gas Sensor and Switch Operating in Air With Metal-Organic Frameworks Coating

    KAUST Repository

    Jaber, Nizar

    2017-11-03

    We report a resonant gas sensor, uniformly coated with a metal-organic framework (MOF), and excited it near the higher order modes for a higher attained sensitivity. Also, switching upon exceeding a threshold value is demonstrated by operating the resonator near the bifurcation point and the dynamic pull-in instabilities. The resonator is based on an electrostatically excited clamped-clamped microbeam. The microbeam is fabricated from a polyimide layer coated from the top with Cr/Au and from the bottom with Cr/Au/Cr layer. The geometry of the resonator is optimized to reduce the effect of squeeze film damping, thereby allowing operation under atmospheric pressure. The electrostatic electrode is designed to enhance the excitation of the second mode of vibration with the minimum power required. Significant frequency shift (kHz) is demonstrated for the first time upon water vapor, acetone, and ethanol exposure due to the MOF functionalization and the higher order modes excitation. Also, the adsorption dynamics and MOF selectivity is investigated by studying the decaying time constants of the response upon gas exposure.

  14. Statistical mechanics of binary mixture adsorption in metal-organic frameworks in the osmotic ensemble

    Science.gov (United States)

    Dunne, Lawrence J.; Manos, George

    2018-03-01

    Although crucial for designing separation processes little is known experimentally about multi-component adsorption isotherms in comparison with pure single components. Very few binary mixture adsorption isotherms are to be found in the literature and information about isotherms over a wide range of gas-phase composition and mechanical pressures and temperature is lacking. Here, we present a quasi-one-dimensional statistical mechanical model of binary mixture adsorption in metal-organic frameworks (MOFs) treated exactly by a transfer matrix method in the osmotic ensemble. The experimental parameter space may be very complex and investigations into multi-component mixture adsorption may be guided by theoretical insights. The approach successfully models breathing structural transitions induced by adsorption giving a good account of the shape of adsorption isotherms of CO2 and CH4 adsorption in MIL-53(Al). Binary mixture isotherms and co-adsorption-phase diagrams are also calculated and found to give a good description of the experimental trends in these properties and because of the wide model parameter range which reproduces this behaviour suggests that this is generic to MOFs. Finally, a study is made of the influence of mechanical pressure on the shape of CO2 and CH4 adsorption isotherms in MIL-53(Al). Quite modest mechanical pressures can induce significant changes to isotherm shapes in MOFs with implications for binary mixture separation processes. This article is part of the theme issue `Modern theoretical chemistry'.

  15. Sintering-Resistant Single-Site Nickel Catalyst Supported by Metal-Organic Framework.

    Science.gov (United States)

    Li, Zhanyong; Schweitzer, Neil M; League, Aaron B; Bernales, Varinia; Peters, Aaron W; Getsoian, Andrew Bean; Wang, Timothy C; Miller, Jeffrey T; Vjunov, Aleksei; Fulton, John L; Lercher, Johannes A; Cramer, Christopher J; Gagliardi, Laura; Hupp, Joseph T; Farha, Omar K

    2016-02-17

    Developing supported single-site catalysts is an important goal in heterogeneous catalysis since the well-defined active sites afford opportunities for detailed mechanistic studies, thereby facilitating the design of improved catalysts. We present herein a method for installing Ni ions uniformly and precisely on the node of a Zr-based metal-organic framework (MOF), NU-1000, in high density and large quantity (denoted as Ni-AIM) using atomic layer deposition (ALD) in a MOF (AIM). Ni-AIM is demonstrated to be an efficient gas-phase hydrogenation catalyst upon activation. The structure of the active sites in Ni-AIM is proposed, revealing its single-site nature. More importantly, due to the organic linker used to construct the MOF support, the Ni ions stay isolated throughout the hydrogenation catalysis, in accord with its long-term stability. A quantum chemical characterization of the catalyst and the catalytic process complements the experimental results. With validation of computational modeling protocols, we further targeted ethylene oligomerization catalysis by Ni-AIM guided by theoretical prediction. Given the generality of the AIM methodology, this emerging class of materials should prove ripe for the discovery of new catalysts for the transformation of volatile substrates.

  16. Chemical Reactions Catalyzed by Metalloporphyrin-Based Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Kelly Aparecida Dias de Freitas Castro

    2013-06-01

    Full Text Available The synthetic versatility and the potential application of metalloporphyrins (MP in different fields have aroused researchers’ interest in studying these complexes, in an attempt to mimic biological systems such as cytochrome P-450. Over the last 40 years, synthetic MPs have been mainly used as catalysts for homogeneous or heterogeneous chemical reactions. To employ them in heterogeneous catalysis, chemists have prepared new MP-based solids by immobilizing MP onto rigid inorganic supports, a strategy that affords hybrid inorganic-organic materials. More recently, materials obtained by supramolecular assembly processes and containing MPs as building blocks have been applied in a variety of areas, like gas storage, photonic devices, separation, molecular sensing, magnets, and heterogeneous catalysis, among others. These coordination polymers, known as metal-organic frameworks (MOFs, contain organic ligands or complexes connected by metal ions or clusters, which give rise to a 1-, 2- or 3-D network. These kinds of materials presents large surface areas, Brønsted or redox sites, and high porosity, all of which are desirable features in catalysts with potential use in heterogeneous phases. Building MOFs based on MP is a good way to obtain solid catalysts that offer the advantages of bioinspired systems and zeolitic materials. In this mini review, we will adopt a historical approach to present the most relevant MP-based MOFs applicable to catalytic reactions such as oxidation, reduction, insertion of functional groups, and exchange of organic functions.

  17. Boosting Catalytic Performance of Metal-Organic Framework by Increasing the Defects via a Facile and Green Approach.

    Science.gov (United States)

    Ye, Gan; Zhang, Dan; Li, Xiangfu; Leng, Kunyue; Zhang, Wenjuan; Ma, Jun; Sun, Yinyong; Xu, Wei; Ma, Shengqian

    2017-10-11

    The control of defects in crystalline materials has long been of significance since the defects are correlated with the performances of the materials. Yet such control remains a challenge for metal-organic frameworks (MOFs), which are usually well-crystallized under hydro-/solvothermal conditions. In this contribution, we demonstrate for the first time how to increase the defects of MOF via a facile and green approach as exemplified in the context of solvent-free synthesis of UiO-66(Zr). Such increase of defects leads to drastic enhancement of catalysis performance when compared to UiO-66(Zr) prepared from conventional hydro-/solvothermal synthesis. Our work therefore not only opens a new door for boosting the catalytic activities of MOFs but also contributes a new approach to control the defects in crystalline materials for various applications.

  18. An Ising model for metal-organic frameworks

    Science.gov (United States)

    Höft, Nicolas; Horbach, Jürgen; Martín-Mayor, Victor; Seoane, Beatriz

    2017-08-01

    We present a three-dimensional Ising model where lines of equal spins are frozen such that they form an ordered framework structure. The frame spins impose an external field on the rest of the spins (active spins). We demonstrate that this "porous Ising model" can be seen as a minimal model for condensation transitions of gas molecules in metal-organic frameworks. Using Monte Carlo simulation techniques, we compare the phase behavior of a porous Ising model with that of a particle-based model for the condensation of methane (CH4) in the isoreticular metal-organic framework IRMOF-16. For both models, we find a line of first-order phase transitions that end in a critical point. We show that the critical behavior in both cases belongs to the 3D Ising universality class, in contrast to other phase transitions in confinement such as capillary condensation.

  19. Robust and conductive two-dimensional metal-organic frameworks with exceptionally high volumetric and areal capacitance

    Science.gov (United States)

    Feng, Dawei; Lei, Ting; Lukatskaya, Maria R.; Park, Jihye; Huang, Zhehao; Lee, Minah; Shaw, Leo; Chen, Shucheng; Yakovenko, Andrey A.; Kulkarni, Ambarish; Xiao, Jianping; Fredrickson, Kurt; Tok, Jeffrey B.; Zou, Xiaodong; Cui, Yi; Bao, Zhenan

    2018-01-01

    For miniaturized capacitive energy storage, volumetric and areal capacitances are more important metrics than gravimetric ones because of the constraints imposed by device volume and chip area. Typically used in commercial supercapacitors, porous carbons, although they provide a stable and reliable performance, lack volumetric performance because of their inherently low density and moderate capacitances. Here we report a high-performing electrode based on conductive hexaaminobenzene (HAB)-derived two-dimensional metal-organic frameworks (MOFs). In addition to possessing a high packing density and hierarchical porous structure, these MOFs also exhibit excellent chemical stability in both acidic and basic aqueous solutions, which is in sharp contrast to conventional MOFs. Submillimetre-thick pellets of HAB MOFs showed high volumetric capacitances up to 760 F cm-3 and high areal capacitances over 20 F cm-2. Furthermore, the HAB MOF electrodes exhibited highly reversible redox behaviours and good cycling stability with a capacitance retention of 90% after 12,000 cycles. These promising results demonstrate the potential of using redox-active conductive MOFs in energy-storage applications.

  20. Facile preparation of magnetic metal organic frameworks core–shell nanoparticles for stimuli-responsive drug carrier

    Science.gov (United States)

    Li, Sheng; Bi, Ke; Xiao, Ling; Shi, Xiaowen

    2017-12-01

    Facile synthesis of core–shell magnetic MOFs for drug delivery is of significance due to the advantages of high drug load and easy separation. In this work, magnetic metal organic frameworks (MOFs, Fe3O4-NH2@MIL101-NH2) core–shell nanoparticles were synthesized rapidly in water phase by microwave irradiation using Fe3+ and 2-amino-1,4-benzenedicarboxylate (BDC-NH2) as metal ions and ligands respectively. The resulting magnetic MOFs exhibit large surface areas (96.04 m2 g‑1), excellent magnetic response (20.47 emu g‑1) and large mesopore volume (22.07 cm3 g‑1) along with spherical morphologies with the diameters ranging from 140–330 nm. Using doxorubicin (DOX) as a model drug, the drug loading capacity of Fe3O4-NH2@MIL101-NH2 could reach 36.02%, substantially higher than pristine MIL101-NH2. Importantly, the release of DOX could be controlled by pH as well as the meso pore size of MOFs. The cytotoxicity assay showed that the magnetic MOFs have low cytotoxicity and good biocompatibility. The results suggest great potential of the magnetic MOFs core–shell nanoparticles fabricated in this study on controlled drug release of DOX.

  1. Self-Template-Directed Metal-Organic Frameworks Network and the Derived Honeycomb-Like Carbon Flakes via Confinement Pyrolysis.

    Science.gov (United States)

    Wang, Jie; Tang, Jing; Ding, Bing; Chang, Zhi; Hao, Xiaodong; Takei, Toshiaki; Kobayashi, Naoya; Bando, Yoshio; Zhang, Xiaogang; Yamauchi, Yusuke

    2018-02-16

    Metal-organic frameworks (MOFs) have become a research hotspot since they have been explored as convenient precursors for preparing various multifunctional nanomaterials. However, the preparation of MOF networks with controllable flake morphology in large scale is not realized yet. Herein, a self-template strategy is developed to prepare MOF networks. In this work, layered double-metal hydroxide (LDH) and other layered metal hydroxides are used not only as a scaffold but also as a self-sacrificed metal source. After capturing the abundant metal cations identically from the LDH by the organic linkers, MOF networks are in situ formed. It is interesting that the MOF network-derived carbon materials retain the flake morphology and exhibit a unique honeycomb-like macroporous structure due to the confined shrinkage of the polyhedral facets. The overall properties of the carbon networks are adjustable according to the tailored metal compositions in LDH and the derived MOFs, which are desirable for target-oriented applications as exemplified by the electrochemical application in supercapacitors. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. High-Throughput Screening of Metal-Organic Frameworks for CO2 Capture in the Presence of Water.

    Science.gov (United States)

    Li, Song; Chung, Yongchul G; Snurr, Randall Q

    2016-10-11

    Competitive coadsorption of water is a major problem in the deployment of adsorption-based CO 2 capture. Water molecules may compete for adsorption sites, reducing the capacity of the material, and dehumidification prior to separating CO 2 from N 2 increases process complexity and cost. The development of adsorbent materials that can selectively adsorb CO 2 in the presence of water would be a major step forward in the deployment of CO 2 capture materials in practice. In this study, large-scale computational screening was carried out to search for metal-organic frameworks (MOFs) with high selectivity toward CO 2 over H 2 O. Calculating framework charges for thousands of MOFs is a significant challenge, so initial screening used a fast, but approximate, charge calculation method. On the basis of the initial screening, 15 MOFs were selected, and Monte Carlo simulations were carried out to compute the adsorption isotherms for these MOFs using more accurate framework charges calculated by density functional theory. A detailed investigation was performed on the effect of using different methods for calculating partial charges, and it was found that electrostatic interactions contribute the majority of the adsorption energy of H 2 O in the selected MOFs.

  3. Minimal Edge-Transitive Nets for the Design and Construction of Metal-Organic Frameworks

    KAUST Repository

    Eddaoudi, Mohamed

    2017-04-05

    Highly-connected and minimal edge-transitive nets (with one or two kinds of edge) can be regarded as ideal blueprints for the rational design and construction of metal-organic frameworks (MOFs). Here we report and affirm the prominence of highly-connected nets as suitable targets in reticular chemistry for the design and synthesis of MOFs. Of special interest are augmented highly-connected binodal edge-transitive nets embedding a unique and precise positioning and connectivity of the net vertex figures, regarded as net-coded building units (net-cBUs). Explicitly, a definite net-cBU encompasses precise geometrical information that codes uniquely and matchlessly a selected net, a compelling perquisite for the rational design of MOFs. Interestingly, the double six-membered ring (d6R) building unit offers great prospective to be deployed as a net-cBU for the deliberate reticulation of the sole two edge-transitive nets with a vertex figure as a d6R, namely the (4,12)-coordinated shp net (square and hexagonal prism) and the (6,12)-coordinated alb net (aluminium diboride, hexagonal prism and trigonal prism). Conceivably, we envisioned and proposed various MOF structures based on the derived shp and alb nets. Gaining access to the requisite net-cBUs is essential for the successful practice of reticular chemistry; correspondingly organic and organic chemistries were deployed to afford concomitant molecular building blocks (MBBs) with the looked-for shape and connectivity. Practically, the combination of the 12-connected (12-c) rare-earth (RE) polynuclear, points of extension matching the 12 vertices of the hexagonal prism (d6R) with a 4-connected tetracarboxylate ligand or a 6-connected hexacarboxylate ligand afforded the targeted shp-MOF or alb-MOF, respectively. Intuitively, a dodecacarboxylate ligand can be conceived and purported as a compatible 12-c MBB, plausibly affording the positioning of the carbon centers of the twelve carboxylate groups on the vertices of the

  4. Reticular Chemistry and Metal-Organic Frameworks: Design and Synthesis of Functional Materials for Clean Energy Applications

    KAUST Repository

    Alezi, Dalal A.

    2017-06-01

    Gaining control over the assembly of crystalline solid-state materials has been significantly advanced through the field of reticular chemistry and metal organic frameworks (MOFs). MOFs have emerged as a unique modular class of porous materials amenable to a rational design with targeted properties for given applications. Several design approaches have been deployed to construct targeted functional MOFs, where desired structural and geometrical attributes are incorporated in preselected building units prior to the assembly process. This dissertation illustrates the merit of the molecular building block approach (MBB) for the rational construction and discovery of stable and highly porous MOFs, and their exploration as potential gas storage medium for sustainable and clean energy applications. Specifically, emphasis was placed on gaining insights into the structure-property relationships that impact the methane (CH4) storage in MOFs and its subsequent delivery. The foreseen gained understanding is essential for the design of new adsorbent materials or adjusting existing MOF platforms to encompass the desired features that subsequently afford meeting the challenging targets for methane storage in mobile and stationary applications.In this context, we report the successful use of the MBB approach for the design and deliberate construction of a series of novel isoreticular, highly porous and stable, aluminum based MOFs with the square-octahedral (soc) underlying net topology. From this platform, Al-soc-MOF-1, with more than 6000 m2/g apparent Langmuir specific surface area, exhibits outstanding gravimetric CH4 uptake (total and working capacities). It is shown experimentally, for the first time, that the Al-soc-MOF platform can address the U.S. Department of Energy (DOE) challenging gravimetric and volumetric targets for the CH4 working capacity for on-board CH4 storage. Furthermore, Al-soc-MOF-1 exhibits the highest total gravimetric and volumetric uptake for carbon

  5. Influence of metal doping of a MOF-74 framework on hydrogen adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Botas, J.A.; Calleja, G.; Orcajo, M.G. [Rey Juan Carlos Univ., Madrid (Spain). Dept. of Chemical and Energy Technology; Sanchez-Sanchez, M. [CSIC, Madrid (Spain). Inst. de Catalisis y Petroleoquimica

    2010-07-01

    Microporous Metal-Organic Framework (MOF) adsorbents are considered an interesting option for hydrogen storage. Due to their porous nature and unusually high surface areas, these materials show an exceptional H{sub 2} uptake. Unfortunately, their interaction with H{sub 2} molecules is weak, so cryogenic temperatures are required to reach competitive H{sub 2} storage capacities. In this sense, the presence of coordinatively unsaturated and exposed metal centers in some MOF frameworks could increase the affinity for H{sub 2} through stronger metal-H{sub 2} interactions. In this preliminary work, the effect of doping a Zn{sup 2+}-MOF-74 framework with Co{sup 2+}, Cu{sup 2+} and Mg{sup 2+} on its adsorption properties for H{sub 2} has been studied. Characterization studies suggest that the samples prepared have actually the MOF-74 structure, in which the different tested heteroatom ions have been successfully incorporated. The differences in H{sub 2} adsorption at 77 K and 87 K between the MOF-74 samples doped with the mentioned divalent metal ions were discussed as a function of their free pore volume and amount of metal incorporation. (orig.)

  6. Alkylamine functionalized metal-organic frameworks for composite gas separations

    Energy Technology Data Exchange (ETDEWEB)

    Long, Jeffrey R.; McDonald, Thomas M.; D' Alessandro, Deanna M.

    2018-01-09

    Functionalized metal-organic framework adsorbents with ligands containing basic nitrogen groups such as alkylamines and alkyldiamines appended to the metal centers and method of isolating carbon dioxide from a stream of combined gases and carbon dioxide partial pressures below approximately 1 and 1000 mbar. The adsorption material has an isosteric heat of carbon dioxide adsorption of greater than -60 kJ/mol at zero coverage using a dual-site Langmuir model.

  7. Removal of Congo red dye from aqueous solution with nickel-based metal-organic framework/graphene oxide composites prepared by ultrasonic wave-assisted ball milling.

    Science.gov (United States)

    Zhao, Shuaiqi; Chen, Ding; Wei, Fuhua; Chen, Nini; Liang, Zhao; Luo, Yun

    2017-11-01

    Metal-organic frameworks (MOFs) were successfully synthesized by ultrasonic wave-assisted ball milling. In the absence of organic solvent, the coupling effect of ultrasonic wave and mechanical force played an significant role in the synthesis of MOFs. Adsorption of Congo red (CR) was studied in view of adsorption kinetic, isotherm and thermodynamics. The adsorbent was carried out using X-ray diffraction (XRD), thermogravimetric analysis (TGA), N 2 adsorption-desorption isotherms, Raman spectroscopy and scanning electron microscope (SEM) methods. It was found that pseudo-second-order kinetic model and Freundlich adsorption isotherm matched well for the adsorption of CR onto nickel-based metal-organic framework/graphene oxide composites (Ni-MOF/GO). The results of the adsorption thermodynamics indicated that the adsorption process was a spontaneous and endothermic process. The adsorption capacity of graphene oxide/metal-organic frameworks (GO/MOFs) for CR reached 2489mg/g, much higher than previous reports. It was demonstrated that an increase in the number of active metal sites can dramatically improve the adsorption capacity of dye. A suitable dry temperature is beneficial for the improvement of adsorption capacity for dye. In this paper, the adsorption results indicated that ultrasonic wave-assisted ball milling has a good prospect for synthesis of MOFs with excellent adsorption performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Nanoparticle-Directed Metal-Organic Framework/Porous Organic Polymer Monolithic Supports for Flow-Based Applications.

    Science.gov (United States)

    Darder, María Del Mar; Salehinia, Shima; Parra, José B; Herrero-Martinez, José M; Svec, Frantisek; Cerdà, Víctor; Turnes Palomino, Gemma; Maya, Fernando

    2017-01-18

    A two-step nanoparticle-directed route for the preparation of macroporous polymer monoliths for which the pore surface is covered with a metal-organic framework (MOF) coating has been developed to facilitate the use of MOFs in flow-based applications. The flow-through monolithic matrix was prepared in a column format from a polymerization mixture containing ZnO-nanoparticles. These nanoparticles embedded in the precursor monolith were converted to MOF coatings via the dissolution-precipitation equilibrium after filling the pores of the monolith with a solution of the organic linker. Pore surface coverage with the microporous zeolitic imidazolate framework ZIF-8 resulted in an increase in surface area from 72 to 273 m 2 g -1 . Monolithic polymer containing ZIF-8 coating was implemented as a microreactor catalyzing the Knoevenagel condensation reaction and also in extraction column format enabling the preconcentration of trace levels of toxic chlorophenols in environmental waters. Our approach can be readily adapted to other polymers and MOFs thus enabling development of systems for flow-based MOF applications.

  9. Metal-Organic Framework Thin Film Coated Optical Fiber Sensors: A Novel Waveguide-Based Chemical Sensing Platform.

    Science.gov (United States)

    Kim, Ki-Joong; Lu, Ping; Culp, Jeffrey T; Ohodnicki, Paul R

    2018-02-23

    Integration of optical fiber with sensitive thin films offers great potential for the realization of novel chemical sensing platforms. In this study, we present a simple design strategy and high performance of nanoporous metal-organic framework (MOF) based optical gas sensors, which enables detection of a wide range of concentrations of small molecules based upon extremely small differences in refractive indices as a function of analyte adsorption within the MOF framework. Thin and compact MOF films can be uniformly formed and tightly bound on the surface of etched optical fiber through a simple solution method which is critical for manufacturability of MOF-based sensor devices. The resulting sensors show high sensitivity/selectivity to CO 2 gas relative to other small gases (H 2 , N 2 , O 2 , and CO) with rapid (optical fiber platform which results in an amplification of inherent optical absorption present within the MOF-based sensing layer with increasing values of effective refractive index associated with adsorption of gases.

  10. Development of Metal-Organic Framework for Gaseous Plant Hormone Encapsulation To Manage Ripening of Climacteric Produce.

    Science.gov (United States)

    Zhang, Boce; Luo, Yaguang; Kanyuck, Kelsey; Bauchan, Gary; Mowery, Joseph; Zavalij, Peter

    2016-06-29

    Controlled ripening of climacteric fruits, such as bananas and avocados, is a critical step to provide consumers with high-quality products while reducing postharvest losses. Prior to ripening, these fruits can be stored for an extended period of time but are usually not suitable for consumption. However, once ripening is initiated, they undergo irreversible changes that lead to rapid quality loss and decay if not consumed within a short window of time. Therefore, technologies to slow the ripening process after its onset or to stimulate ripening immediately before consumption are in high demand. In this study, we developed a solid porous metal-organic framework (MOF) to encapsulate gaseous ethylene for subsequent release. We evaluated the feasibility of this technology for on-demand stimulated ripening of bananas and avocados. Copper terephthalate (CuTPA) MOF was synthesized via a solvothermal method and loaded with ethylene gas. Its crystalline structure and chemical composition were characterized by X-ray diffraction crystallography, porosity by N2 and ethylene isotherms, and morphology by electron microscopy. The MOF loaded with ethylene (MOF-ethylene) was placed inside sealed containers with preclimacteric bananas and avocados and stored at 16 °C. The headspace gas composition and fruit color and texture were monitored periodically. Results showed that this CuTPA MOF is highly porous, with a total pore volume of 0.39 cm(3)/g. A 50 mg portion of MOF-ethylene can absorb and release up to 654 μL/L of ethylene in a 4 L container. MOF-ethylene significantly accelerated the ripening-related color and firmness changes of treated bananas and avocados. This result suggests that MOF-ethylene technology could be used for postharvest application to stimulate ripening just before the point of consumption.

  11. Construction of robust open metal-organic frameworks with chiral channels and permanent porosity.

    Science.gov (United States)

    Sun, Daofeng; Ke, Yanxiong; Collins, David J; Lorigan, Gary A; Zhou, Hong-Cai

    2007-04-02

    Four new metal-organic frameworks (MOFs) containing chiral channels have been synthesized using an achiral, triazine-based trigonal-planar ligand, 4,4',4' '-s-triazine-2,4,6-triyltribenzoate (TATB), and an hourglass secondary building unit (SBU): Zn3(TATB)2(H2O)2.4DMF.6H2O (1); Cd3(TATB)2(H2O)2.7DMA.10H2O (2); [H2N(CH3)2][Zn3(TATB)2(HCOO)].HN(CH3)2.3DMF.3H2O (3); [H2N(CH3)2][Cd3(TATB)2(CH3COO)].HN(CH3)2.3DMA.4H2O (4). MOFs 1 and 2 are isostructural and possess (10,3)-a nets containing large chiral channels of 20.93 and 21.23 A, respectively, but are thermally unstable due to the easy removal of coordinated water molecules on the SBU. Replacement of these water molecules by formate or acetate generated in situ leads to 3 and 4, respectively. Formate or acetate links SBUs to form infinite helical chains bridged by TATB to create three-dimensional anionic networks, in which one of the two oxygen atoms of the formate or acetate is uncoordinated and points into the void of the channels. This novel SBU-stabilization and channel-functionalization strategy may have general implications in the preparation of new MOFs. Thermogravimetric analysis (TGA) shows that solvent-free 3' is thermally stable to 410 degrees C, while TGA studies on samples vapor-diffused with water, methanol, and chloroform show reversible adsorption. MOF 3 also has permanent porosity with a large Langmuir surface area of 1558 m2/g. All complexes exhibit similar strong luminescence with a lambdamax of approximately 423 nm upon excitation at 268.5 nm.

  12. Luminescent metal-organic framework-functionalized graphene oxide nanocomposites and the reversible detection of high explosives

    Science.gov (United States)

    Lee, Ji Ha; Jaworski, Justyn; Jung, Jong Hwa

    2013-08-01

    Achieving both high specificity and sensitivity are essential for gas phase chemical detection systems. Recent implementation of Metal-Organic Frameworks (MOFs) have shown great success in separation and storage systems for specific gas molecules. By implementing a MOF structure comprised of Zn2+ coordinated trans-stilbene derivatives, a gas responsive material has been created which exhibits a high photoluminescence quantum yield, offering new opportunities for chemical sensors. Here, we reveal a nanocomposite material, assembled from azobenzene functionalized graphene oxide and stilbene-MOF, that is capable of luminescent quenching by explosive gases. This unique system displays selectivity to dinitrotoluene (71% quenching) over trinitrotoluene (20% quenching) with sub ppm sensitivity and response times of less than a minute. We show that this implementation of a graphene-based MOF composite provides a unique strategy in the development of molecularly well-defined materials having rapid, reversible, and gas selective fluorescent quenching capabilities. This opens the way for new advances in the assembly of low density frameworks using isomerization suppressed materials.Achieving both high specificity and sensitivity are essential for gas phase chemical detection systems. Recent implementation of Metal-Organic Frameworks (MOFs) have shown great success in separation and storage systems for specific gas molecules. By implementing a MOF structure comprised of Zn2+ coordinated trans-stilbene derivatives, a gas responsive material has been created which exhibits a high photoluminescence quantum yield, offering new opportunities for chemical sensors. Here, we reveal a nanocomposite material, assembled from azobenzene functionalized graphene oxide and stilbene-MOF, that is capable of luminescent quenching by explosive gases. This unique system displays selectivity to dinitrotoluene (71% quenching) over trinitrotoluene (20% quenching) with sub ppm sensitivity and

  13. A novel cryogenic magnetic refrigerant metal-organic framework based on 1D gadolinium(III) chain

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Qun; Li, Peng-Fei [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Zou, Zhi-Ming, E-mail: 2014005@glut.edu.cn [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Liu, Zheng [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Liu, Shu-Xia, E-mail: liusx@nenu.edu.cn [Key Laboratory of Polyoxometalate Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China)

    2017-02-15

    A metal-organic framework (MOF) based on gadolinium ion (Gd{sup 3+}) and tricarboxylate ligand, [Gd(BTPCA)(H{sub 2}O)]·2DMF·3H{sub 2}O (Gd-BTPCA) (H{sub 3}BTPCA =1,1′,1′-(benzene-1,3,5-triyl)tripiperidine-4-carboxylic acid; DMF=dimethylformamide), was synthesized and structurally characterized. The adjacent Gd{sup 3+} ions are intraconnected by the carboxylate groups of the BTPCA{sup 3-} ligands to form a 1D Gd{sup 3+} ion chain. The 1D Gd{sup 3+} ion chains are interconnected by the BTPCA{sup 3-} ligands, giving rise to a 3D framework with 1D open channel. The magnetic studies indicate that Gd-BTPCA exhibits weak ferromagnetic interactions, and acts as a cryogenic magnetic refrigerant having the magnetic entropy change (−ΔS{sub m}) of 20.40 J kg{sup −1} K{sup −1} for ΔH =7 T at 3 K. - Graphical abstract: A 1D gadolinium(III) chains-based metal-organic framework performed ferromagnetic coupling on the magnetic property. Magnetic investigation reveals that Gd-BTPCA exhibits the entropy change (−ΔS{sub m}) of 20.40 J kg{sup −1} K{sup −1} for ΔH =7 T at 3 K. - Highlights: • The MOF based on gadolinium ion and tricarboxylate ligand was synthesized. • This MOF is connected with 1D Gd{sup 3+} ions chain and the carboxylate groups of BTPCA{sup 3-} ligands. • The magnetic studies indicate that the MOF exhibits the weak ferromagnetic interactions. • Magnetic investigation reveals that the MOF exhibits the high entropy change.

  14. Integration of Plasmonic Effects and Schottky Junctions into Metal-Organic Framework Composites: Steering Charge Flow for Enhanced Visible-Light Photocatalysis.

    Science.gov (United States)

    Xiao, Juan-Ding; Han, Lili; Luo, Jun; Yu, Shu-Hong; Jiang, Hai-Long

    2018-01-22

    A wide range of light absorption and rapid electron-hole separation are desired for efficient photocatalysis. Herein, on the basis of a semiconductor-like metal-organic framework (MOF), a Pt@MOF/Au catalyst with two types of metal-MOF interfaces integrates the surface plasmon resonance excitation of Au nanorods with a Pt-MOF Schottky junction, which not only extends the light absorption of the MOF from the UV to the visible region but also greatly accelerates charge transfer. The spatial separation of Pt and Au particles by the MOF further steers the formation of charge flow and expedites the charge migration. As a result, the Pt@MOF/Au presents an exceptionally high photocatalytic H 2 production rate by water splitting under visible light irradiation, far superior to Pt/MOF/Au, MOF/Au and other counterparts with similar Pt or Au contents, highlighting the important role of each component and the Pt location in the catalyst. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Stability and Hydrocarbon/Fluorocarbon Sorption of a Metal-Organic Framework with Fluorinated Channels

    Directory of Open Access Journals (Sweden)

    Jijiang Xie

    2016-04-01

    Full Text Available The stabilities and hydrocarbon/fluorocarbon sorption properties of a zeolite-like metal-organic framework (MOF Zn(hfipbb with fluorinated channels has been studied. By the combination of thermogravimetric analysis (TGA and powder X-ray diffraction (PXRD measurements, we confirm that Zn(hfipbb has exceptionally high hydrothermal and thermal stabilities. The adsorption behaviors of water and methanol by Zn(hfipbb indicate that it is highly hydrophobic but with high adsorption of alcohols. Hexane and perfluorohexane adsorption measurements show that the fluorinated channels in Zn(hfipbb have high affinity with hydrocarbon and fluorocarbon. The high fluorophilic nature of the channels and the high stability of the compound suggest its potential utility in practical separation applications.

  16. One metal-organic frameworks showing two-dimensional sheet structure: Synthesis, structure, and magnetic property

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yong Hong [School of Chemistry and Material Science, Huaibei Normal University, Huaibei (China); Wang, Zhe Yu [No. 1 High School of Huaibei, Huaibei (China)

    2015-02-15

    Under hydrothermal condition, the reaction of 2,4-dichlorophenoxyacetic acid (2,4-DH) and 1,3-bis(4-pyridyl)propane with MnCl{sub 2} ·2H{sub 2}O gave a novel metal-organic framework (MOF), [Mn(2,4-D)2 (H{sub 2}O){sub 2}]{sub n} (1). This complex was characterized by IR, elemental analysis, powder X-ray diffraction, and thermogravimetry analysis. X-Ray single-crystal diffraction shows that the Mn(II) ions are bidendate bridged by carboxyl groups in the syn–anti mode, giving a two-dimensional (2D) network. Temperature-dependent magnetic studies reveal that there are weak antiferromagnetic exchange interactions between the Mn(II) ions transmitted by carboxyl groups.

  17. Highly selective luminescent sensing of picric acid based on a water-stable europium metal-organic framework

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Tifeng; Zhu, Fengliang; Cui, Yuanjing, E-mail: cuiyj@zju.edu.cn; Yang, Yu; Wang, Zhiyu; Qian, Guodong, E-mail: gdqian@zju.edu.cn

    2017-01-15

    A water-stable metal-organic framework (MOF) EuNDC has been synthesized for selective detection of the well-known contaminant and toxicant picric acid (PA) in aqueous solution. Due to the photo-induced electron transfer and self-absorption mechanism, EuNDC displayed rapid, selective and sensitive detection of PA with a detection limit of 37.6 ppb. Recyclability experiments revealed that EuNDC retains its initial luminescent intensity and same quenching efficiency in each cycle, suggesting high photostability and reusability for long-term sensing applications. The excellent detection performance of EuNDC makes it a promising PA sensing material for practical applications. - Graphical abstract: A water-stable europium-based metal-organic framework has been reported for highly selective sensing of picric acid (PA) with a detection limit of 37.6 ppb in aqueous solution. - Highlights: • A water-stable metal-organic framework (MOF) EuNDC was synthesized. • The highly selective detection of picric acid with a detection limit of 37.6 ppb was realized. • The detection mechanism were also presented and discussed.

  18. Sulfation of metal-organic framework: Opportunities for acid catalysis and proton conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Goesten, M.G.; Stavitski, E.; Juan-Alcaniz, J.; Ramos-Fernandez, E.V.; Sai Sankar Gupta, K.B.; van Bekkum, H.; Gascon, J. and Kapteijn, F.

    2011-05-24

    A new post-functionalization method for metal-organic frameworks (MOFs) has been developed to introduce acidity for catalysis. Upon treatment with a mixture of triflic anhydride and sulfuric acid, chemically stable MOF structures MIL-101(Cr) and MIL-53(Al) can be sulfated, resulting in a Broensted sulfoxy acid group attached to up to 50% of the aromatic terephthalate linkers of the structure. The sulfated samples have been extensively characterized by solid-state NMR, XANES, and FTIR spectroscopy. The functionalized acidic frameworks show catalytic activity similar to that of acidic polymers like Nafion{reg_sign} display in the esterification of n-butanol with acetic acid (TOF {approx} 1 min{sup -1} {at} 343 K). Water adsorbs strongly up to 4 molecules per sulfoxy acid group, and an additional 2 molecules are taken up at lower temperatures in the 1-D pore channels of S-MIL-53(Al). The high water content and Broensted acidity provide the structure S-MIL-53(Al) a high proton conductivity up to moderate temperatures.

  19. Formation of Ultrathin, Continuous Metal-Organic Framework Membranes on Flexible Polymer Substrates.

    Science.gov (United States)

    Hou, Jingwei; Sutrisna, Putu D; Zhang, Yatao; Chen, Vicki

    2016-03-14

    Metal-organic framework (MOF) materials have an enormous potential in separation applications, but to realize their potential as semipermeable membranes they need to be assembled into thin continuous macroscopic films for fabrication into devices. By using a facile immersion technique, we prepared ultrathin, continuous zeolitic imidazolate framework (ZIF-8) membranes on titania-functionalized porous polymeric supports. The coherent ZIF-8 layer was surprisingly flexible and adhered well to the support, and the composite membrane could sustain bending and elongation. The membranes exhibited molecular sieving behavior, close to the theoretical permeability of ZIF-8, with hydrogen permeance up to 201×10(-7)  mol m(-2)  s(-1)  Pa(-1) and an ideal H2 /CO2 selectivity of 7:1. This approach offers significant opportunities to exploit the unique properties of MOFs in the fabrication of separation and sensing devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. High CO2 Uptake Capacity and Selectivity in a Fascinating Nanotube-Based Metal-Organic Framework.

    Science.gov (United States)

    Wu, Yun-Long; Qian, Jinjie; Yang, Guo-Ping; Yang, Fan; Liang, Yu-Tong; Zhang, Wen-Yan; Wang, Yao-Yu

    2017-01-17

    An unusual porous metal-organic framework has been synthesized by using Pb(II) and rigid V-shaped 4,4'-(pyridine-3,5-diyl)diisophthalic acid (H 4 L). Structure analysis reveals that there exist 1D cylindrical 14.26 Å and triangular prism 10.69 × 10.69 × 10.69 Å 3 nanotubes in the framework. Gas sorption behavior of the nanoporous MOF shows a relatively high capacity and selectivity of CO 2 over CH 4 .

  1. Photonic metal-organic framework composite spheres: a new kind of optical material with self-reporting molecular recognition.

    Science.gov (United States)

    Cui, Jiecheng; Gao, Ning; Wang, Chen; Zhu, Wei; Li, Jian; Wang, Hui; Seidel, Philipp; Ravoo, Bart Jan; Li, Guangtao

    2014-10-21

    Exploiting metal-organic framework (MOF) materials as novel building blocks to construct superstructures with extended and enhanced functions represents a big challenge. In biological systems, the ordering of many components is not achieved by interaction of the components with each other, but by interaction of each component with the host protein which provides a matrix to support the entire assembly. Inspired by biological systems, in this work, a general strategy for efficient spatial arrangement of MOF materials was developed by using spherical colloidal crystals as host matrices, affording a new class of highly tunable MOF composite spheres with a series of distinctive properties. It was found that the synergetic combination of the unique features of both MOF and photonic colloidal crystal imparted these hierarchically structured spheres intrinsic optical properties, specific molecular recognition with self-reporting signalling, derivatization capability, and anisotropy. More importantly, the unique photonic band-gap structure integrated in these composite spheres provides a more convenient means to manipulate the photophysical and photochemical behaviour of the trapped guest molecules in MOF nanocavities.

  2. A peroxidase mimic with atom transfer radical polymerization activity constructed through the grafting of heme onto metal-organic frameworks.

    Science.gov (United States)

    Jiang, Wei; Pan, Yue; Yang, Jiebing; Liu, Yong; Yang, Yan; Tang, Jun; Li, Quanshun

    2018-03-09

    Atom transfer radical polymerization (ATRP) has been considered to be an efficient strategy for constructing functional macromolecules owing to its simple operation and versatile monomers, and thus it is of great significance to develop ideal catalysts with higher activity and perfect reusability. We constructed a peroxidase mimic through the grafting of heme onto metal-organic frameworks UiO-66-NH 2 (ZrMOF), namely Heme-ZrMOF. After the systematic characterization of structure, the composite Heme-ZrMOF was demonstrated to possess high peroxidase activity using 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) and 3,3',5,5'-tetramethylbenzidine as substrates. The enzyme mimic was then used as catalysts in the ATRP reactions of different monomers, in which favorable monomer conversion (44.6-98.0%) and product molecular weight (8600-25,600 g/mol) could be obtained. Compared to free heme, Heme-ZrMOF could efficiently achieve the easy separation of heme from the catalytic system and facilitate the ATRP reaction in an aqueous environment to avoid the utilization of organic solvents. In conclusion, the enzyme mimic Heme-ZrMOF could be potentially used as an effective catalyst for preparing well-defined polymers with biomedical applications. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Plonka, Anna M.; Wang, Qi; Gordon, Wesley O.; Balboa, Alex; Troya, Diego; Guo, Weiwei; Sharp, Conor H.; Senanayake, Sanjaya D.; Morris, John R.; Hill, Craig L.; Frenkel, Anatoly I. (BNL); (Virginia Tech); (ECBC); (Emory); (SBU)

    2017-01-18

    Zr-based metal organic frameworks (MOFs) have been recently shown to be among the fastest catalysts of nerve-agent hydrolysis in solution. We report a detailed study of the adsorption and decomposition of a nerve-agent simulant, dimethyl methylphosphonate (DMMP), on UiO-66, UiO-67, MOF-808, and NU-1000 using synchrotron-based X-ray powder diffraction, X-ray absorption, and infrared spectroscopy, which reveals key aspects of the reaction mechanism. The diffraction measurements indicate that all four MOFs adsorb DMMP (introduced at atmospheric pressures through a flow of helium or air) within the pore space. In addition, the combination of X-ray absorption and infrared spectra suggests direct coordination of DMMP to the Zr6 cores of all MOFs, which ultimately leads to decomposition to phosphonate products. These experimental probes into the mechanism of adsorption and decomposition of chemical warfare agent simulants on Zr-based MOFs open new opportunities in rational design of new and superior decontamination materials.

  4. Recent advances in syntheses and biomedical applications of nano-rare earth metal-organic framework materials

    Directory of Open Access Journals (Sweden)

    Xin Pengyan

    2017-12-01

    Full Text Available In recent years,the syntheses of nano-rare earth metal-organic framework (MOF materials and their applications in biomedicine,especially in the diagnosis and treatment of cancer have attracted extensive attentions.On the one hand,nano-rare earth MOFs,which have unique optical and magnetic properties,are promising multimodal imaging contrast agents for biomedical imaging,such as fluorescence imaging and magnetic resonance imaging.On the other hand,nano-rare earth MOFs have various compositions and structures,and excellent intrinsic properties such as large specific surface area,high pore volume and tunable pore size,which enable them to perform as promising nanoplatforms for drug delivery.Therefore,nano-rare earth MOFs may provide a new platform for the development of diagnostic and therapeutic reagents.In this article,the recent advances in the syntheses of nano-rare earth MOFs and their applications in biomedicine are summarized.

  5. Layer-by-Layer Method for the Synthesis and Growth of Surface Mounted Metal-Organic Frameworks (SURMOFs

    Directory of Open Access Journals (Sweden)

    Osama Shekhah

    2010-02-01

    Full Text Available A layer-by-layer method has been developed for the synthesis of metal-organic frameworks (MOFs and their deposition on functionalized organic surfaces. The approach is based on the sequential immersion of functionalized organic surfaces into solutions of the building blocks of the MOF, i.e., the organic ligand and the inorganic unit. The synthesis and growth of different types of MOFs on substrates with different functionalization, like COOH, OH and pyridine terminated surfaces, were studied and characterized with different surface characterization techniques. A controlled and highly oriented growth of very homogenous films was obtained using this method. The layer-by-layer method offered also the possibility to study the kinetics of film formation in more detail using surface plasmon resonance and quartz crystal microbalance. In addition, this method demonstrates the potential to synthesize new classes of MOFs not accessible by conventional methods. Finally, the controlled growth of MOF thin films is important for many applications like chemical sensors, membranes and related electrodes.

  6. Transition metal complexes supported on metal-organic frameworks for heterogeneous catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Farha, Omar K.; Hupp, Joseph T.; Delferro, Massimiliano; Klet, Rachel C.

    2017-02-07

    A robust mesoporous metal-organic framework comprising a hafnium-based metal-organic framework and a single-site zirconium-benzyl species is provided. The hafnium, zirconium-benzyl metal-organic framework is useful as a catalyst for the polymerization of an alkene.

  7. Hemin immobilized into metal-organic frameworks as an electrochemical biosensor for 2,4,6-trichlorophenol

    Science.gov (United States)

    Zhang, Ting; Wang, Lu; Gao, Congwei; Zhao, Chaoyue; Wang, Yang; Wang, Jianmin

    2018-02-01

    Hemin immobilized into copper-based metal-organic frameworks was successfully prepared and used as a new electrode material for sensitive electrochemical biosensing. X-ray diffraction patterns, Fourier transform infrared spectra, scanning electron microscopy, UV-vis absorption spectroscopy, and cyclic voltammetry were used to characterize the resultant composites. Due to the interaction between the copper atom groups and hemin, the constrained environment in Cu-MOF-74 acts as a matrix to avoid the dimerization of enzyme molecules and retain its biological activity. The hemin/Cu-MOF composites demonstrated enhanced electrocatalytical activity and high stability towards the oxidation of 2,4,6-trichlorophenol. Under optimum experimental conditions, the sensor showed a wide linear relationship over the range of 0.01-9 μmol L-1 with a detection limit (3σ) of 0.005 μmol L-1. The relative standard deviations were 4.6% and 3.5% for five repeated measurements of 0.5 and 5 μmol L-1 2,4,6-trichlorophenol, respectively. The detection platforms for 2,4,6-trichlorophenol developed here not only indicate that hemin/Cu-MOF-74 possesses intrinsic biological reactivity, but also enable further work to be conducted towards the application of enzyme-containing metal-organic frameworks in electrochemical biosensors.

  8. Metal-organic frameworks as adsorbents for hydrogen purification and precombustion carbon dioxide capture.

    Science.gov (United States)

    Herm, Zoey R; Swisher, Joseph A; Smit, Berend; Krishna, Rajamani; Long, Jeffrey R

    2011-04-20

    Selected metal-organic frameworks exhibiting representative properties--high surface area, structural flexibility, or the presence of open metal cation sites--were tested for utility in the separation of CO(2) from H(2) via pressure swing adsorption. Single-component CO(2) and H(2) adsorption isotherms were measured at 313 K and pressures up to 40 bar for Zn(4)O(BTB)(2) (MOF-177, BTB(3-) = 1,3,5-benzenetribenzoate), Be(12)(OH)(12)(BTB)(4) (Be-BTB), Co(BDP) (BDP(2-) = 1,4-benzenedipyrazolate), H(3)[(Cu(4)Cl)(3)(BTTri)(8)] (Cu-BTTri, BTTri(3-) = 1,3,5-benzenetristriazolate), and Mg(2)(dobdc) (dobdc(4-) = 1,4-dioxido-2,5-benzenedicarboxylate). Ideal adsorbed solution theory was used to estimate realistic isotherms for the 80:20 and 60:40 H(2)/CO(2) gas mixtures relevant to H(2) purification and precombustion CO(2) capture, respectively. In the former case, the results afford CO(2)/H(2) selectivities between 2 and 860 and mixed-gas working capacities, assuming a 1 bar purge pressure, as high as 8.6 mol/kg and 7.4 mol/L. In particular, metal-organic frameworks with a high concentration of exposed metal cation sites, Mg(2)(dobdc) and Cu-BTTri, offer significant improvements over commonly used adsorbents, indicating the promise of such materials for applications in CO(2)/H(2) separations.

  9. Metal-organic framework based on copper(I) sulfate and 4,4'-bipyridine catalyzes the cyclopropanation of styrene

    International Nuclear Information System (INIS)

    Shi Fanian; Silva, Ana Rosa; Rocha, Joao

    2011-01-01

    The hydrothermal synthesis of a new metal-organic framework (MOF) formulated as Cu 2 (4,4'-bpy) 2 SO 4 .6(H 2 O), [abbreviation: (1); bpy or 4,4'-bpy=4,4'-bipyridine; SO 4 2- =sulfate group] has been reported. The structure of this MOF consists of Cu + nodes connected via 4,4'-bpy to form infinite chains, with two neighboring chains further bridged on the nodes by SO 4 2- , resulting in a 1-D double chain network. Guest water molecules reside in between the chains and are hydrogen-bonded to the O and S atoms from the nearest sulfate groups, leading to the formation of a 3-D supramolecular framework. This MOF is good heterogeneous catalyst for the cyclopropanation of styrene, with high trans cyclopropane diastereoselectivity and was recycled and reused for three consecutive cycles without a significant loss of catalytic activity. - Graphical Abstract: A new MOF structure built up of 4,4 ' -bipyridine, sulphate and Cu(I), is an active heterogeneous catalyst for cyclopropanation of styrene with ethyldiazoacetate. Highlights: → The synthesis is different from solvothermal synthesis for other Cu(I) compounds. → The compound and the structure are new. → H bonds form infinite planes among water molecules and sulphate species. → H bonding interaction makes the structure into a 3D supramolecular framework. → Active catalytic property as heterogeneous catalyst for cyclopropanation of styrene.

  10. Topologies of metal-organic frameworks based on pyrimidine-5-carboxylate and unexpected gas-sorption selectivity for CO(2).

    Science.gov (United States)

    Seo, Jinwoo; Jin, Narae; Chun, Hyungphil

    2010-12-06

    A simple and multitopic ligand, pyrimidine-5-carboxylate (pmc), has been used to obtain a series of metal-organic frameworks (MOFs) based on Co(2+), Cd(2+), and Cu(2+). The networks possess well-defined topologies of body-centered-cubic, rutile, and interpenetrated NbO structures, respectively. Among those, [Cu(pmc)(2)] possesses a permanent porosity resulting from straight one-dimensional channels of 5.5 Å free passages. Unexpectedly, this porous MOF displays a highly selective sorption behavior for CO(2), and the sorptions of N(2), Ar, O(2), H(2), and CH(4) at two different temperatures are found to be negligible. The results of diffraction and spectroscopic analyses exclude framework dynamics or incomplete evacuation as the origin of the gas-sorption selectivity.

  11. Evaluation of MOF-74, MOF-177, and ZIF-8 for the Removal of Toxic Industrial Chemicals

    National Research Council Canada - National Science Library

    Peterson, Gregory W; Mahle, John; Balboa, Alex; Wagner, George; Sewell, Tara; Karwacki, Christopher J

    2008-01-01

    .... Metal-organic frameworks (MOFs) and zeolitic imidazolate frameworks (ZIFs) are two novel classes of materials that allow for specific functionalities to be designed directly into a porous framework...

  12. Enhanced binding affinity, remarkable selectivity, and high capacity of CO 2 by dual functionalization of a rht-type metal-organic framework

    KAUST Repository

    Li, Baiyan

    2011-12-23

    Open and friendly: The smallest member of the rht-type metal-organic frameworks (MOFs, see picture) constructed by a hexacarboxylate ligand with a nitrogen-rich imino triazine backbone shows a significantly enhanced gas binding affinity relative to all other isoreticular rht-type MOFs. The high adsorption capacity and remarkable selectivity of CO 2 are attributed to the high density of open metal and Lewis basic sites in the framework. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Valuing Metal-Organic Frameworks for Postcombustion Carbon Capture: A Benchmark Study for Evaluating Physical Adsorbents.

    Science.gov (United States)

    Adil, Karim; Bhatt, Prashant M; Belmabkhout, Youssef; Abtab, Sk Md Towsif; Jiang, Hao; Assen, Ayalew H; Mallick, Arijit; Cadiau, Amandine; Aqil, Jamal; Eddaoudi, Mohamed

    2017-10-01

    The development of practical solutions for the energy-efficient capture of carbon dioxide is of prime importance and continues to attract intensive research interest. Conceivably, the implementation of adsorption-based processes using different cycling modes, e.g., pressure-swing adsorption or temperature-swing adsorption, offers great prospects to address this challenge. Practically, the successful deployment of practical adsorption-based technologies depends on the development of made-to-order adsorbents expressing mutually two compulsory requisites: i) high selectivity/affinity for CO 2 and ii) excellent chemical stability in the presence of impurities. This study presents a new comprehensive experimental protocol apposite for assessing the prospects of a given physical adsorbent for carbon capture under flue gas stream conditions. The protocol permits: i) the baseline performance of commercial adsorbents such as zeolite 13X, activated carbon versus liquid amine scrubbing to be ascertained, and ii) a standardized evaluation of the best reported metal-organic framework (MOF) materials for carbon dioxide capture from flue gas to be undertaken. This extensive study corroborates the exceptional CO 2 capture performance of the recently isolated second-generation fluorinated MOF material, NbOFFIVE-1-Ni, concomitant with an impressive chemical stability and a low energy for regeneration. Essentially, the NbOFFIVE-1-Ni adsorbent presents the best compromise by satisfying all the required metrics for efficient CO 2 scrubbing. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Valuing Metal-Organic Frameworks for Postcombustion Carbon Capture: A Benchmark Study for Evaluating Physical Adsorbents

    KAUST Repository

    Adil, Karim

    2017-08-22

    The development of practical solutions for the energy-efficient capture of carbon dioxide is of prime importance and continues to attract intensive research interest. Conceivably, the implementation of adsorption-based processes using different cycling modes, e.g., pressure-swing adsorption or temperature-swing adsorption, offers great prospects to address this challenge. Practically, the successful deployment of practical adsorption-based technologies depends on the development of made-to-order adsorbents expressing mutually two compulsory requisites: i) high selectivity/affinity for CO2 and ii) excellent chemical stability in the presence of impurities. This study presents a new comprehensive experimental protocol apposite for assessing the prospects of a given physical adsorbent for carbon capture under flue gas stream conditions. The protocol permits: i) the baseline performance of commercial adsorbents such as zeolite 13X, activated carbon versus liquid amine scrubbing to be ascertained, and ii) a standardized evaluation of the best reported metal-organic framework (MOF) materials for carbon dioxide capture from flue gas to be undertaken. This extensive study corroborates the exceptional CO2 capture performance of the recently isolated second-generation fluorinated MOF material, NbOFFIVE-1-Ni, concomitant with an impressive chemical stability and a low energy for regeneration. Essentially, the NbOFFIVE-1-Ni adsorbent presents the best compromise by satisfying all the required metrics for efficient CO2 scrubbing.

  15. Prediction of large gap flat Chern band in a two-dimensional metal-organic framework

    Science.gov (United States)

    Su, Ninghai; Jiang, Wei; Wang, Zhengfei; Liu, Feng

    2018-01-01

    Systems with a flat Chern band have been extensively studied for their potential to realize high-temperature fractional quantum Hall states. To experimentally observe the quantum transport properties, a sizable topological gap is highly necessary. Here, taking advantage of the high tunability of two-dimensional (2D) metal-organic frameworks (MOFs), whose crystal structures can be easily tuned using different metal atoms and molecular ligands, we propose a design of a 2D MOF [Tl2(C6H4)3, Tl2Ph3] showing nontrivial topological states with an extremely large gap in both the nearly flat Chern band and the Dirac bands. By coordinating π-conjugated thallium ions and benzene rings, crystalline Tl2Ph3 can be formed with Tl and Ph constructing honeycomb and kagome lattices, respectively. The px,y orbitals of Tl on the honeycomb lattice form ideal pxy four-bands, through which a flat Chern band with a spin-orbit coupling (SOC) gap around 140 meV evolves below the Fermi level. This is the largest SOC gap among all the theoretically proposed organic topological insulators so far.

  16. Insulator-to-Proton-Conductor Transition in a Dense Metal-Organic Framework.

    Science.gov (United States)

    Tominaka, Satoshi; Coudert, François-Xavier; Dao, Thang D; Nagao, Tadaaki; Cheetham, Anthony K

    2015-05-27

    Metal-organic frameworks (MOFs) are prone to exhibit phase transitions under stimuli such as changes in pressure, temperature, or gas sorption because of their flexible and responsive structures. Here we report that a dense MOF, ((CH3)2NH2)2[Li2Zr(C2O4)4], exhibits an abrupt increase in proton conductivity from topotactic hydration (H2O/Zr = 0.5), wherein one-fourth of the Li ions are irreversibly rearranged and coordinated by water molecules. This structure further transforms into a third crystalline structure by water uptake (H2O/Zr = 4.0). The abrupt increase in conductivity is reversible and is associated with the latter reversible structure transformation. The H2O molecules coordinated to Li ions, which are formed in the first step of the transformation, are considered to be the proton source, and the absorbed water molecules, which are formed in the second step, are considered to be proton carriers.

  17. Specific oriented metal-organic framework membranes and their facet-tuned separation performance.

    Science.gov (United States)

    Mao, Yiyin; Su, Binbin; Cao, Wei; Li, Junwei; Ying, Yulong; Ying, Wen; Hou, Yajun; Sun, Luwei; Peng, Xinsheng

    2014-09-24

    Modulating the crystal morphology, or the exposed crystal facets, of metal-organic frameworks (MOFs) expands their potential applications in catalysis, adsorption, and separation. In this article, by immobilizing the citrate modulators on Au nanoparticles and subsequently being fixed on solid copper hydroxide nanostrands, a well-intergrown and oriented HKUST-1 cube crystal membrane was formed at room temperature. In contrast, in the absence of Au nanoparticles, well-intergrown and oriented cuboctahedron and octahedron membranes were formed in water/ethanol and ethanol, respectively. The gas separation performances of these HKUST-1 membranes were tuned via their exposed facets with defined pore sizes. The HKUST-1 cube membrane with exposed {001} facets demonstrated the highest permeance but lowest gas binary separation factors, while the octahedron membrane with exposed {111} facets presented the highest separation factors but lowest permeance, since the window size of {111} facets is 0.46 nm which is smaller than 0.9 nm of {001} facets. Separation of 0.38 nm CO2 from 0.55 nm SF6 was realized by the HKUST-1 octahedron membrane. As a proof of concept, this will open a new way to design MOF-related separation membranes by facet controlling.

  18. Quasi-1D physics in metal-organic frameworks: MIL-47(V from first principles

    Directory of Open Access Journals (Sweden)

    Danny E. P. Vanpoucke

    2014-10-01

    Full Text Available The geometric and electronic structure of the MIL-47(V metal-organic framework (MOF is investigated by using ab initio density functional theory (DFT calculations. Special focus is placed on the relation between the spin configuration and the properties of the MOF. The ground state is found to be antiferromagnetic, with an equilibrium volume of 1554.70 Å3. The transition pressure of the pressure-induced large-pore-to-narrow-pore phase transition is calculated to be 82 MPa and 124 MPa for systems with ferromagnetic and antiferromagnetic chains, respectively. For a mixed system, the transition pressure is found to be a weighted average of the ferromagnetic and antiferromagnetic transition pressures. Mapping DFT energies onto a simple-spin Hamiltonian shows both the intra- and inter-chain coupling to be antiferromagnetic, with the latter coupling constant being two orders of magnitude smaller than the former, suggesting the MIL-47(V to present quasi-1D behavior. The electronic structure of the different spin configurations is investigated and it shows that the band gap position varies strongly with the spin configuration. The valence and conduction bands show a clear V d-character. In addition, these bands are flat in directions orthogonal to VO6 chains, while showing dispersion along the the direction of the VO6 chains, similar as for other quasi-1D materials.

  19. Exploiting Diffusion Barrier and Chemical Affinity of Metal-Organic Frameworks for Efficient Hydrogen Isotope Separation.

    Science.gov (United States)

    Kim, Jin Yeong; Balderas-Xicohténcatl, Rafael; Zhang, Linda; Kang, Sung Gu; Hirscher, Michael; Oh, Hyunchul; Moon, Hoi Ri

    2017-10-25

    Deuterium plays a pivotal role in industrial and scientific research, and is irreplaceable for various applications such as isotope tracing, neutron moderation, and neutron scattering. In addition, deuterium is a key energy source for fusion reactions. Thus, the isolation of deuterium from a physico-chemically almost identical isotopic mixture is a seminal challenge in modern separation technology. However, current commercial approaches suffer from extremely low separation efficiency (i.e., cryogenic distillation, selectivity of 1.5 at 24 K), requiring a cost-effective and large-scale separation technique. Herein, we report a highly effective hydrogen isotope separation system based on metal-organic frameworks (MOFs) having the highest reported separation factor as high as ∼26 at 77 K by maximizing synergistic effects of the chemical affinity quantum sieving (CAQS) and kinetic quantum sieving (KQS). For this purpose, the MOF-74 system having high hydrogen adsorption enthalpies due to strong open metal sites is chosen for CAQS functionality, and imidazole molecules (IM) are employed to the system for enhancing the KQS effect. To the best of our knowledge, this work is not only the first attempt to implement two quantum sieving effects, KQS and CAQS, in one system, but also provides experimental validation of the utility of this system for practical industrial usage by isolating high-purity D 2 through direct selective separation studies using 1:1 D 2 /H 2 mixtures.

  20. Self-assembly of polyhedral metal-organic framework particles into three-dimensional ordered superstructures

    Science.gov (United States)

    Avci, Civan; Imaz, Inhar; Carné-Sánchez, Arnau; Pariente, Jose Angel; Tasios, Nikos; Pérez-Carvajal, Javier; Alonso, Maria Isabel; Blanco, Alvaro; Dijkstra, Marjolein; López, Cefe; Maspoch, Daniel

    2018-01-01

    Self-assembly of particles into long-range, three-dimensional, ordered superstructures is crucial for the design of a variety of materials, including plasmonic sensing materials, energy or gas storage systems, catalysts and photonic crystals. Here, we have combined experimental and simulation data to show that truncated rhombic dodecahedral particles of the metal-organic framework (MOF) ZIF-8 can self-assemble into millimetre-sized superstructures with an underlying three-dimensional rhombohedral lattice that behave as photonic crystals. Those superstructures feature a photonic bandgap that can be tuned by controlling the size of the ZIF-8 particles and is also responsive to the adsorption of guest substances in the micropores of the ZIF-8 particles. In addition, superstructures with different lattices can also be assembled by tuning the truncation of ZIF-8 particles, or by using octahedral UiO-66 MOF particles instead. These well-ordered, sub-micrometre-sized superstructures might ultimately facilitate the design of three-dimensional photonic materials for applications in sensing.

  1. Silver nanoparticles embedded over porous metal organic frameworks for carbon dioxide fixation via carboxylation of terminal alkynes at ambient pressure.

    Science.gov (United States)

    Molla, Rostam Ali; Ghosh, Kajari; Banerjee, Biplab; Iqubal, Md Asif; Kundu, Sudipta K; Islam, Sk Manirul; Bhaumik, Asim

    2016-09-01

    Ag nanoparticles (NPs) has been supported over a porous Co(II)-salicylate metal-organic framework to yield a new nanocatalyst AgNPs/Co-MOF and it has been thoroughly characterized by powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), energy dispersive X-ray spectrometry (EDX), high-resolution transmission electron microscopy (HR-TEM), UV-vis diffuse reflection spectroscopy (DRS) and N2 adsorption/desorption analysis. The AgNPs/Co-MOF material showed high catalytic activity in the carboxylation of terminal alkynes via CO2 fixation reaction to yield alkynyl carboxylic acids under very mild conditions. Due to the presence of highly reactive AgNPs bound at the porous MOF framework the reaction proceeded smoothly at 1atm CO2 pressure. Moreover, the catalyst is very convenient to handle and it can be reused for several reaction cycles without appreciable loss of catalytic activity in this CO2 fixation reaction, which suggested a promising future of AgNPs/Co-MOF nanocatalyst. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Amino-functionalized metal-organic frameworks as tunable heterogeneous basic catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, M.; Hartmann, M. [Erlangen-Nuernberg Univ., Erlangen (Germany). Erlangen Catalysis Resource Center

    2011-07-01

    Metal-organic framework (MOF) materials have been explored for applications in heterogeneous catalysis in recent years. In addition to the use of MOFs as supports for the deposition of highly dispersed metal particles, the incorporation of active centers such as coordinatively unsaturated metal sites and the functionalization of the organic linkers with acidic or basic groups seems to be most promising. In our contribution, three different MOFs carrying amino groups at their organic linkers, namely Fe-MIL-101-NH{sub 2} (S{sub BET} = 3438 m{sup 2}g{sup -1}), Al-MIL-101-NH{sub 2} (S{sub BET} = 3099 m{sup 2}g{sup -1}) and CAU-1 (S{sub BET} = 1492 m{sup 2}g{sup -1}), were synthesized and tested in the Knoevenagel condensation of benzaldehyde with malononitrile and with ethyl cyanoacetate, respectively. It is shown that the expected products benzylidenemalononitrile (BzMN) and ethyl a-cyanocinnamate (EtCC) are formed with selectivities of more than 99 % and yields of 90 to 95 % after 3 h (for BzMN). Due to the very small pore windows of CAU-1 (0.3 to 0.4 nm) the reaction proceeds much slower over this catalyst in comparison to the amino-MIL-101 derivatives, which possess open pore windows of up to 1.6 nm. Finally, leaching tests confirm that the reaction is heterogeneously catalyzed. Moreover, the catalysts are recyclable without significant loss of activity. (orig.)

  3. Co-metal-organic-frameworks with pure uniform crystal morphology prepared via Co2 + exchange-mediated transformation from Zn-metallogels for luminol catalysed chemiluminescence

    Science.gov (United States)

    Tang, Xue Qian; Xiao, Bo Wen; Li, Chun Mei; Wang, Dong Mei; Huang, Cheng Zhi; Li, Yuan Fang

    2017-03-01

    Cation exchange-mediated transformation from Zn-metallogels (MOGs), which was a mild facile strategy relative to the demanding hydrothermal method, was employed to develop Co2 + metal-organic frameworks (Co-MOFs) at room temperature. The obtained Co-MOFs was of uniform octahedral morphology and possessed high activity to catalyze luminol chemiluminescence without extra oxidants. By adding cysteine, the CL emission of luminol-Co-MOFs system was further enhanced. Based on this phenomenon, Co-MOFs was utilized to build a practical sensing platform for cysteine determination. Under the optimized conditions, the relative CL intensity (ΔI) was proportional to the concentration of cysteine in the range of 2-10 μM, and the detection limit was 0.49 μM (3S/N). Moreover, the established method was applied to the determination of cysteine in commercially available pharmaceutical injections.

  4. Microporous Hexanuclear Ln(III) Cluster-Based Metal-Organic Frameworks: Color Tunability for Barcode Application and Selective Removal of Methylene Blue.

    Science.gov (United States)

    Gao, Ming-Liang; Wang, Wen-Jing; Liu, Lin; Han, Zheng-Bo; Wei, Na; Cao, Xiao-Man; Yuan, Da-Qiang

    2017-01-03

    Two hexanuclear Ln(III) cluster-based metal-organic frameworks (MOFs) (Ln = Tb or Eu) and a series of isomorphic bimetallic Ln(III)-MOFs have been synthesized by changing the ratio of Tb(III) and Eu(III) under solvothermal conditions. The excellent linear color tunability (from green to red) makes them suitable for barcode application. In addition, the anionic Ln(III)-MOFs exhibit superior uptake capacity toward methylene blue (MB + ) by an ion-exchange process, and its reversible adsorption performance makes 1 suitable for removal of organic dye MB + . The as-prepared anionic hexanuclear Ln(III) cluster-based MOFs can serve as a multifunctional material for an optical and environmental area.

  5. Synthesis of a Zr-Based Metal-Organic Framework with Spirobifluorenetetrabenzoic Acid for the Effective Removal of Nerve Agent Simulants.

    Science.gov (United States)

    Park, Hea Jung; Jang, Jin Kyu; Kim, Seo-Yul; Ha, Jong-Woon; Moon, Dohyun; Kang, In-Nam; Bae, Youn-Sang; Kim, Suhkmann; Hwang, Do-Hoon

    2017-10-16

    A new microporous Zr(IV)-based metal-organic framework (MOF) containing 4,4',4″,4‴-(9,9'-spirobi[fluorene]-2,2',7,7'-tetrayl)tetrabenzoic acid (Spirof-MOF) was synthesized, characterized, and size-controlled for the adsorption and decomposition of a nerve agent simulant, dimethyl 4-nitrophenylphosphate (DMNP). Spirof-MOF showed a hydrolysis half-life (t 1/2 ) of 7.5 min to DMNP, which was confirmed by using in situ 31 P NMR spectroscopy. Additionally, size-controlled Spirof-MOFb (∼1 μm) exhibited a half-life of 1.8 min and 99% removal within 18 min for DMNP. The results show that Spirof-MOF is a new active material in removing nerve agent simulants by adsorption and hydrolytic decomposition.

  6. Hydrogen molecule binding to unsaturated metal sites in metal-organic frameworks studied by neutron powder diffraction and inelastic neutron scattering

    Science.gov (United States)

    Liu, Yun; Brown, Craig; Neumann, Dan; Dinca, Mircea; Long, Jeffrey; Peterson, Vanessa; Kepert, Cameron

    2007-03-01

    Metal organic framework (MOF) materials have shown considerable potential for hydrogen storage arising from very large surface areas. However, the low binding energy of hydrogen molecules limits its storage capability to very low temperatures (industrial applications. Using neutron powder diffraction (NPD), we have characterized the hydrogen adsorption sites in a selected series of MOF materials with exposed unsaturated metal ions. Direct binding between the unsaturated metal ions and hydrogen molecules is observed and responsible for the enhanced initial hydrogen adsorption enthalpy. The different metals centers in these MOFs show different binding strength and interaction distances between the hydrogen molecule and metal ions. The organic linker also affects the overall H2 binding strength. Inelastic neutron scattering spectra of H2 in these MOFs are also discussed.

  7. Langmuir-Blodgett Films of the Metal-Organic Framework MIL-101(Cr): Preparation, Characterization, and CO2 Adsorption Study Using a QCM-Based Setup.

    Science.gov (United States)

    Benito, Javier; Sorribas, Sara; Lucas, Irene; Coronas, Joaquin; Gascon, Ignacio

    2016-06-29

    This work reports the fabrication and characterization of Langmuir-Blodgett films of nanoparticles (size 51 ± 10 nm) of the metal organic framework MIL-101(Cr). LB film characterization by SEM, UV-vis, GIXRD, and QCM has shown that the addition of 1 wt % of behenic acid to MOF dispersion allows obtaining dense monolayers at the air-water interface that can be deposited onto solid substrates of different nature with transfer ratios close to 1. Moreover, a QCM-based setup has been built and used for the first time to measure CO2 adsorption isotherms at 303 K on MOF LB films, proving that LB films with MOF masses between 1.2 (1 layer) and 2.3 (2 layers) μg can be used to obtain accurate adsorption values at 100 kPa, similar to those obtained by conventional adsorption methods that require much larger MOF quantities (tens of milligrams).

  8. A porous Cd(II) metal-organic framework with high adsorption selectivity for CO2 over CH4

    Science.gov (United States)

    Zhu, Chunlan

    2017-05-01

    Metal-organic frameworks (MOFs) have attracted a lot of attention in recent decades. We applied a semi-rigid four-carboxylic acid linker to assemble with Cd(II) ions to generate a novel microporous Cd(II) MOF material. Single crystal X-ray diffraction study reveals the different two dimension (2D) layers can be further packed together with an AB fashion by hydrogen bonds (O4sbnd H4⋯O7 = 1.863 Å) to construct a three dimension (3D) supermolecular architecture. The resulting sample can be synthesized under solvothermal reactions successfully, which exhibits high selectivity adsorption of CO2 over CH4 at room temperature. In addition, the obtained sample was characterized by thermal gravimetric analyses (TGA), Fourier-transform infrared spectra (FT-IR), elemental analysis (CHN) and powder X-ray diffraction (PXRD).

  9. Efficient and selective oxidation of sulfur mustard using singlet oxygen generated by a pyrene-based metal-organic framework.

    Science.gov (United States)

    Liu, Yangyang; Buru, Cassandra T; Howarth, Ashlee J; Mahle, John J; Buchanan, James H; DeCoste, Jared B; Hupp, Joseph T; Farha, Omar K

    2016-01-01

    A pyrene-based metal-organic framework (MOF) NU-1000 was used as a heterogeneous photocatalyst for the degradation of a sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES). Using irradiation from a commercially available and inexpensive ultraviolet (UV) light-emitting diode (LED), singlet oxygen ( 1 O 2 ) is generated by NU-1000 and selectively oxidizes CEES to the nontoxic product 2-chloroethyl ethyl sulfoxide (CEESO). More importantly, this method was tested on the warfare agent sulfur mustard (HD) for the first time using 1 O 2 and a MOF catalyst, and this method proved to be effective in oxidizing sulfur mustard to nontoxic products without forming the toxic sulfone by-product.

  10. In Situ Stringing of Metal Organic Frameworks by SiC Nanowires for High-Performance Electromagnetic Radiation Elimination.

    Science.gov (United States)

    Zhang, Kun; Wu, Fan; Xie, Aming; Sun, Mengxiao; Dong, Wei

    2017-09-27

    The design of novel hybrid nanostructures has been seen as an effective route to tune the properties of materials. Herein, we provide an in situ growth strategy to efficiently construct kebab-like hybrids, which are composed of one-dimensional SiC nanowires stringing polyhedral metal organic frameworks (MOFs). Through a heat-treatment process regardless of under air or argon, these hybrids generate an excellent electromagnetic absorption (EMA) ability. We comprehensively explored the growth and calcination process of these hybrids as well as their EMA enhanced mechanism. The results indicate that the MOFs kept as shrunken polyhedrons under air but decomposed to small particles under argon, due to the different calcination mechanism. In addition, the enhanced EMA ability should be attributed to the combined influences of the reduced dielectric constant, enlarged aspect ratio, and enhanced interface polarization. This research opens up the rational designs and applications of novel materials by the hybridizing of nanomaterials in multidimensions.

  11. Probing adsorption sites of carbon dioxide in metal organic framework of [Zn(bdc)(dpds)]n: A molecular simulation study

    Science.gov (United States)

    Lu, Shih-I.; Liao, Jian-Min; Huang, Xiao-Zhuang; Lin, Chia-Hsun; Ke, Szu-Yu; Wang, Chih-Chieh

    2017-11-01

    We used force-field based grand-canonical Monte Carlo simulation method and density functional theory to study adsorption characteristics of carbon dioxide (CO2) molecules in a metal-organic framework (MOF) compound, [Zn(bdc)(dpds)]n. The studied MOF include a metal ion (Zn(II)), an anion organic linker (dianion of benzene dicarboxylicacid, bdc2-) and a neutral organic linker (4,4‧-dipyridyldisulfide, dpds). Results from calculated adsorption isotherms and enthalpies of adsorption agree with the experimental data. The interactions between the adsorbed CO2 and the organic linkers were examined in simulations. Calculated results show available absorption sites are surrounded by two dpds ligands in which an S-S bond as an N-N‧ spacer connect two pyridines. In contrast, the bdc2- ligand does not give a significant contribution to the substantial adsorption amount even though it contains the carboxylate group that provides available bonding site to CO2.

  12. Highly Sensitive and Selective Sensing of Free Bilirubin Using Metal-Organic Frameworks-Based Energy Transfer Process.

    Science.gov (United States)

    Du, Yaran; Li, Xiqian; Lv, Xueju; Jia, Qiong

    2017-09-13

    Free bilirubin, a key biomarker for jaundice, was detected with a newly designed fluorescent postsynthetically modified metal organic framework (MOF) (UIO-66-PSM) sensor. UiO-66-PSM was prepared based on the aldimine condensation reaction of UiO-66-NH 2 with 2,3,4-trihydroxybenzaldehyde. The fluorescence of UIO-66-PSM could be effectively quenched by free bilirubin via a fluorescent resonant energy transfer process, thus achieving its recognition of free bilirubin. It was the first attempt to design a MOF-based fluorescent probe for sensing free bilirubin. The probe exhibited fast response time, low detection limit, wide linear range, and high selectivity toward free bilirubin. The sensing system enabled the monitor of free bilirubin in real human serum. Hence, the reported free bilirubin sensing platform has potential applications for clinical diagnosis of jaundice.

  13. Gas/vapour separation using ultra-microporous metal-organic frameworks: insights into the structure/separation relationship.

    Science.gov (United States)

    Adil, Karim; Belmabkhout, Youssef; Pillai, Renjith S; Cadiau, Amandine; Bhatt, Prashant M; Assen, Ayalew H; Maurin, Guillaume; Eddaoudi, Mohamed

    2017-06-06

    The separation of related molecules with similar physical/chemical properties is of prime industrial importance and practically entails a substantial energy penalty, typically necessitating the operation of energy-demanding low temperature fractional distillation techniques. Certainly research efforts, in academia and industry alike, are ongoing with the main aim to develop advanced functional porous materials to be adopted as adsorbents for the effective and energy-efficient separation of various important commodities. Of special interest is the subclass of metal-organic frameworks (MOFs) with pore aperture sizes below 5-7 Å, namely ultra-microporous MOFs, which in contrast to conventional zeolites and activated carbons show great prospects for addressing key challenges in separations pertaining to energy and environmental sustainability, specifically materials for carbon capture and separation of olefin/paraffin, acetylene/ethylene, linear/branched alkanes, xenon/krypton, etc. In this tutorial review we discuss the latest developments in ultra-microporous MOF adsorbents and their use as separating agents via thermodynamics and/or kinetics and molecular sieving. Appreciably, we provide insights into the distinct microscopic mechanisms governing the resultant separation performances, and suggest a plausible correlation between the inherent structural features/topology of MOFs and the associated gas/vapour separation performance.

  14. Metal-Organic Frameworks Stabilize Solution-Inaccessible Cobalt Catalysts for Highly Efficient Broad-Scope Organic Transformations.

    Science.gov (United States)

    Zhang, Teng; Manna, Kuntal; Lin, Wenbin

    2016-03-09

    New and active earth-abundant metal catalysts are critically needed to replace precious metal-based catalysts for sustainable production of commodity and fine chemicals. We report here the design of highly robust, active, and reusable cobalt-bipyridine- and cobalt-phenanthroline-based metal-organic framework (MOF) catalysts for alkene hydrogenation and hydroboration, aldehyde/ketone hydroboration, and arene C-H borylation. In alkene hydrogenation, the MOF catalysts tolerated a variety of functional groups and displayed unprecedentedly high turnover numbers of ∼2.5 × 10(6) and turnover frequencies of ∼1.1 × 10(5) h(-1). Structural, computational, and spectroscopic studies show that site isolation of the highly reactive (bpy)Co(THF)2 species in the MOFs prevents intermolecular deactivation and stabilizes solution-inaccessible catalysts for broad-scope organic transformations. Computational, spectroscopic, and kinetic evidence further support a hitherto unknown (bpy(•-))Co(I)(THF)2 ground state that coordinates to alkene and dihydrogen and then undergoing σ-complex-assisted metathesis to form (bpy)Co(alkyl)(H). Reductive elimination of alkane followed by alkene binding completes the catalytic cycle. MOFs thus provide a novel platform for discovering new base-metal molecular catalysts and exhibit enormous potential in sustainable chemical catalysis.

  15. Immobilizing Organic-Based Molecular Switches into Metal-Organic Frameworks: A Promising Strategy for Switching in Solid State.

    Science.gov (United States)

    Gui, Bo; Meng, Yi; Xie, Yang; Du, Ke; Sue, Andrew C-H; Wang, Cheng

    2018-01-01

    Organic-based molecular switches (OMS) are essential components for the ultimate miniaturization of nanoscale electronics and devices. For practical applications, it is often necessary for OMS to be incorporated into functional solid-state materials. However, the switching characteristics of OMS in solution are usually not transferrable to the solid state, presumably because of spatial confinement or inefficient conversion in densely packed solid phase. A promising way to circumvent this issue is harboring the functional OMS within the robust and porous environment of metal-organic frameworks (MOFs) as their organic components. In this feature article, recent research progress of OMS-based MOFs is briefly summarized. The switching behaviors of OMS under different stimuli (e.g., light, redox, pH, etc.) in the MOF state are first introduced. After that, the technological applications of these OMS-based MOFs in different areas, including CO 2 adsorption, gas separation, drug delivery, photodynamic therapy, and sensing, are outlined. Finally, perspectives and future challenges are discussed in the conclusion. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Acid Gas Adsorption on Metal-Organic Framework Nanosheets as a Model of an "All-Surface" Material.

    Science.gov (United States)

    Howe, Joshua D; Liu, Yang; Flores, Luis; Dixon, David A; Sholl, David S

    2017-03-14

    To establish a model of metal-organic framework (MOF) surfaces and build an understanding of surface-specific ligand adsorption phenomena in MOFs, we present a computational study exploring multiple models of a series of MOF-2 nanosheet materials, "M-BDCs", with M = Zn, Cu, and Co and BDC = benzene-1,4-dicarboxylate. We study and assess the appropriateness of a series of models ranging from small clusters (18 atoms) to fully periodic sheet models. We additionally study the interactions of these models with acid gases and energy-relevant small molecules (CO, CO 2 , H 2 O, SO 2 , NO 2 , and H 2 S). We employ computational methods ranging from DFT with various exchange-correlation functionals to perturbative and coupled-cluster methods. For these systems, we present binding energies and enthalpies with the various ligands studied as well as IR frequency shifts for the normal modes of these ligands upon complexation with the open-metal sites of these materials. Our calculations lead to an understanding of phenomena unique to MOF surfaces and the importance of the periodicity in these materials in capturing surface-specific adsorption behaviors.

  17. Evaluation of drug loading capabilities of γ-cyclodextrin-metal organic frameworks by high performance liquid chromatography.

    Science.gov (United States)

    Xu, Xiaonan; Wang, Caifen; Li, Haiyan; Li, Xue; Liu, Botao; Singh, Vikramjeet; Wang, Shuxia; Sun, Lixin; Gref, Ruxandra; Zhang, Jiwen

    2017-03-10

    Drug loading into γ-cyclodextrin-metal organic frameworks (γ-CD-MOFs) using the impregnation approach is a laborious process. In this study, a γ-CD-MOF construct (2-5μm particle diameter) was used as the stationary phase under HPLC conditions with the aim to correlate retention properties and drug loading capability of the CD-based structure. Ketoprofen, fenbufen and diazepam were chosen as model drugs with m-xylene as a control analyte to investigate the correlation of drug loading and their chromatographic behaviour in the γ-CD-MOF column. Furthermore, γ-CD itself was also prepared as the stationary phase by coupling with silica in the column to illustrate the enhanced interaction between drugs and γ-CD-MOF as a reference. The retention and loading efficiency of the drugs were determined with different ratios of hexane and ethanol (10:90, 20:80, 50:50, 80:20, 90:10, v/v) at temperatures of 20, 25, 30 and 37°C. With the increment in hexane content, the loading efficiency of ketoprofen and fenbufen increased from 2.39±0.06% to 4.38±0.04% and from 5.82±0.94% to 6.37±0.29%, respectively. The retention time and loading efficiency of ketoprofen and diazepam were the lowest at 30°C while those of fenbufen had the different tendency. The excellent relation between the retention and loading efficiency onto γ-CD-MOF could be clearly observed through mobile phase and temperature investigation. In conclusion, a highly efficient chromatographic method has been established to evaluate the drug loading capability of γ-CD-MOF. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Strategies for Enhancing the Catalytic Performance of Metal-Organic Frameworks in the Fixation of CO2into Cyclic Carbonates.

    Science.gov (United States)

    Taherimehr, Masoumeh; Van de Voorde, Ben; Wee, Lik H; Martens, Johan A; De Vos, Dirk E; Pescarmona, Paolo P

    2017-03-22

    Metal-organic frameworks (MOFs) with accessible Lewis acid sites are finding increasing application in the field of heterogeneous catalysis. However, the structural instability of MOFs when they are exposed to high temperature and/or high pressure often limits their applicability. In this study, two strategies were applied to achieve a MOF catalyst with high stability, activity and selectivity in the reaction of CO 2 with styrene oxide to produce styrene carbonate. In the first approach, a MOF with linkers with high connectivity as MIL-100(Cr) was studied, leading to promising activity and recyclability in consecutive catalytic runs without loss of activity. In the second strategy, a MOF with linkers with lower connectivity but with encapsulated Keggin phosphotungstic acid (MIL-101(Cr)[PTA]) was prepared. However, the activity of this catalyst decreased upon reuse as a consequence of deterioration of the MOF. Further investigations were dedicated to the enhancement of the catalytic performance of MIL-100 and included the variation of the metal centre as well as the type and loading of organic salt acting as nucleophile source. This allowed tuning the nature of the organic halide to the specific porous structure of MIL-100(Cr) to prevent diffusion limitations. The best catalytic performance was obtained for MIL-100(Cr) in combination with EMIMBr ionic liquid, which gave very high styrene carbonate yield (94 %) with complete selectivity after 18 h of reaction at mild temperature (60 °C). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A novel metal organic framework-derived carbon-based catalyst for oxygen reduction reaction in a microbial fuel cell

    Science.gov (United States)

    Zhang, Lihua; Hu, Yongyou; Chen, Junfeng; Huang, Wantang; Cheng, Jianhua; Chen, Yuancai

    2018-04-01

    To improve the power generation of microbial fuel cell (MFC), the cathode is modified to increase its oxygen reduction reaction (ORR) activity by using a Cu, N-incorporated carbon-based material as catalyst, which obtained from pyrolyzing ORR active Cu (II)-based metal organic framework (MOF; Cu-bipy-BTC, bipy = 2,2‧-bipyridine, BTC = 1,3,5-tricarboxylate). MOF-800 (the product of pyrolyzing Cu-bipy-BTC at 800 °C) shows porous structure with micropores ranging from 0.5 to 1.3 nm and mesopores ranging from 27 to 46 nm. It also exhibits improved ORR electrocatalytic activity with a higher current density of -3.06 mA cm-2 compared to Cu-bipy-BTC. Moreover, the charge transfer resistance of MOF-800 cathode (1.38 Ω) is much smaller than that of Cu-bipy-BTC cathode (176.8 Ω). A maximum power density of 326 ± 11 mW m-2 is achieved by MOF-800-MFC, which is 2.6 times of that of Cu-bipy-BTC-MFC and comparable with Pt/C-MFC (402 ± 17 mW m-2). The results imply the enhancements of ORR catalytic activity and electrical conductivity of MOF-800 are due to the enhanced porous structure and abundant active sites (C-N, Cu-Nχ), which result in the improved power generation of MFC. This study provides technical and theoretical validation for the MFC performance improvement by ORR active MOF-derived catalysts modified cathodes.

  20. Effect of chemical structure of S-nitrosothiols on nitric oxide release mediated by the copper sites of a metal organic framework based environment.

    Science.gov (United States)

    Taylor-Edinbyrd, Kiara; Li, Tanping; Kumar, Revati

    2017-05-17

    The effect of chemical structure of different biologically compatible S-nitrosothiols on the solvation environment at catalytic copper sites in a metal organic framework (MOF) suspended in a solution of ethanol is probed using computational methods. The use of a copper based MOF as a storage vehicle and catalyst (copper sites of the MOF) in the controlled and sustained release of chemically stored nitric oxide (NO) from S-nitrosocysteine has been shown to occur both experimentally and computationally [J. Am. Chem. Soc., 2012, 134, 3330-3333; Phys. Chem. Chem. Phys., 2015, 17, 23403]. Previous studies on a copper based MOF, namely HKUST-1, concluded that modifications in the R-group of s-nitrosothiols and/or organic linkers of MOFs led to a method capable of modulating NO release. In order to test the hypothesis that larger R-groups slow down NO release, four different RSNOs (R = cysteine, N-acetylcysteine, N-acetyl-d,l-penicillamine or glutathione) of varying size were investigated, which in turn required the use of a larger copper based MOF. Due to its desirable copper centers and more extensive framework, MOF-143, an analog of HKUST-1 was chosen to further explore both the effect of different RSNOs as well as MOF environments on NO release. Condensed phase classical molecular dynamics simulations are utilized to study the effect of the complex MOF environment as well as the chemical structure and size of the RSNO on the species on the catalytic reaction. The results indicate that in addition to the size of the RSNO species and the organic linkers within the MOF, the reaction rates can be modulated by the molecular structure of the RSNO and furthermore combining different RSNO species can also be used to tune the rate of NO release.

  1. Configurations, band structures and photocurrent responses of 4-(4-oxopyridin-1(4H)-yl)phthalic acid and its metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xingxiu; Qiu, Xiandeng; Yan, Zhishuo; Li, Hongjiang [Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Gong, Yun, E-mail: gongyun7211@cqu.edu.cn [Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Lin, Jianhua, E-mail: jhlin@pku.edu.cn [Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2016-05-15

    4-(4-oxopyridin-1(4 H)-yl)phthalic acid (H{sub 2}L) and three H{sub 2}L-based metal-organic frameworks (MOFs) formulated as ZnL(DPE)(H{sub 2}O)·H{sub 2}O (DPE=(E)-1, 2-di(pyridine −4-yl)ethene) (1), CdL(H{sub 2}O){sub 2} (2) and CdL (3) were synthesized and structurally characterized by single-crystal X-ray diffraction. The free H{sub 2}L ligand shows an enol-form and the L{sup 2−} ligand in the three MOFs exists as the keto-form. Density functional theory (DFT) calculations indicate H{sub 2}L and the three MOFs possess different band structures. Due to the existence of the N-donor, DPE in MOF 1, the conduction band (CB) minimum and band gap of MOF 1 are much lower than those of H{sub 2}L. And MOF 1 yielded much larger photocurrent density than H{sub 2}L upon visible light illumination. Electrochemical impedance spectroscopy (EIS) shows the interfacial charge transfer impedance in the presence of MOF 1 is lower than that in the presence of H{sub 2}L. The hydrous MOF 2 and the anhydrous MOF 3 are both constructed by Cd(II) and L{sup 2−}, and they can be reversibly transformed to each other. However, MOFs 2 and 3 possess different CB minimums and VB maximums, and their band gaps are much larger than that of MOF 1. - Graphical abstract: The free ligand, 4-(4-oxopyridin-1(4H)-yl)phthalic acid (H{sub 2}L) shows different configuration from its three MOFs, and they possess different band structures. MOF 1 yielded much larger visible-light-driven photocurrent density than H{sub 2}L. The hydrous MOF 2 and the anhydrous MOF 3 can be transformed to each other, and they have larger band gaps than MOF 1.

  2. Luminescent Lanthanide Metal Organic Frameworks for cis-Selective Isoprene Polymerization Catalysis

    Directory of Open Access Journals (Sweden)

    Samantha Russell

    2015-11-01

    Full Text Available In this study, we are combining two areas of chemistry; solid-state coordination polymers (or Metal-Organic Framework—MOF and polymerization catalysis. MOF compounds combining two sets of different lanthanide elements (Nd3+, Eu3+/Tb3+ were used for that purpose: the use of neodymium was required due to its well-known catalytic properties in dienes polymerization. A second lanthanide, europium or terbium, was included in the MOF structure with the aim to provide luminescent properties. Several lanthanides-based MOF meeting these criteria were prepared according to different approaches, and they were further used as catalysts for the polymerization of isoprene. Stereoregular cis-polyisoprene was received, which in some cases exhibited luminescent properties in the UV-visible range.

  3. Understanding metal-organic frameworks for solar fuel production

    NARCIS (Netherlands)

    Garcia Santaclara, J.

    2017-01-01

    The fascinating chemical and physical properties of MOFs have recently stimulated exploration of their application for photocatalysis. Despite the intense research effort, the efficiencies of most photocatalytic MOFs for solar fuel generation are still very modest. In this introduction we analyse

  4. Synthesis of Thin Film Composite Metal-Organic Frameworks Membranes on Polymer Supports

    KAUST Repository

    Barankova, Eva

    2017-06-01

    Since the discovery of size-selective metal-organic frameworks (MOF) researchers have tried to manufacture them into gas separation membranes. ZIF-8 became the most studied MOF for membrane applications mainly because of its simple synthesis, good chemical and thermal stability, recent commercial availability and attractive pore size. The aim of this work is to develop convenient methods for growing ZIF thin layers on polymer supports to obtain defect-free ZIF membranes with good gas separation properties. We present new approaches for ZIF membranes preparation on polymers. We introduce zinc oxide nanoparticles in the support as a secondary metal source for ZIF-8 growth. Initially the ZnO particles were incorporated into the polymer matrix and later on the surface of the polymer by magnetron sputtering. In both cases, the ZnO facilitated to create more nucleation opportunities and improved the ZIF-8 growth compared to the synthesis without using ZnO. By employing the secondary seeded growth method, we were able to obtain thin (900 nm) ZIF-8 layer with good gas separation performance. Next, we propose a metal-chelating polymer as a suitable support for growing ZIF layers. Defect-free ZIF-8 films with a thickness of 600 nm could be obtained by a contra-diffusion method. ZIF-8 membranes were tested for permeation of hydrogen and hydrocarbons, and one of the highest selectivities reported so far for hydrogen/propane, and propylene/propane was obtained. Another promising method to facilitate the growth of MOFs on polymeric supports is the chemical functionalization of the support surface with functional groups, which can complex metal ions and which can covalently bond the MOF crystals. We functionalized the surface of a common porous polymeric membrane with amine groups, which took part in the reaction to form ZIF-8 nanocrystals. We observed an enhancement in adhesion between the ZIF layer and the support. The effect of parameters of the contra-diffusion experiment

  5. Cyclodextrin-based metal-organic frameworks particles as efficient carriers for lansoprazole: Study of morphology and chemical composition of individual particles.

    Science.gov (United States)

    Li, Xue; Guo, Tao; Lachmanski, Laurent; Manoli, Francesco; Menendez-Miranda, Mario; Manet, Ilse; Guo, Zhen; Wu, Li; Zhang, Jiwen; Gref, Ruxandra

    2017-10-15

    Cyclodextrin-based metal-organic frameworks (CD-MOFs) represent an environment-friendly and biocompatible class of MOFs drawing increasing attention in drug delivery. Lansoprazole (LPZ) is a proton-pump inhibitor used to reduce the production of acid in the stomach and recently identified as an antitubercular prodrug. Herein, LPZ loaded CD-MOFs were successfully synthesized upon the assembly with γ-CD in the presence of K + ions using an optimized co-crystallization method. They were characterized in terms of morphology, size and crystallinity, showing almost perfect cubic morphologies with monodispersed size distributions. The crystalline particles, loaded or not with LPZ, have mean diameters of around 6μm. The payloads reached 23.2±2.1% (wt) which corresponds to a molar ratio of 1:1 between LPZ and γ-CD. It was demonstrated that even after two years storage, the incorporated drug inside the CD-MOFs maintained its spectroscopic characteristics. Molecular modelling provided a deeper insight into the interaction between the LPZ and CD-MOFs. Raman spectra of individual particles were recorded, confirming the formation of inclusion complexes within the tridimensional CD-MOF structures. Of note, it was found that each individual particle had the same chemical composition. The LPZ-loaded particles had remarkable homogeneity in terms of both drug loading and size. These results pave the way towards the use of CD-MOFs for drug delivery purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Electrical semiconduction modulated by light in a cobalt and naphthalene diimide metal-organic framework

    OpenAIRE

    Castaldelli, Evandro; Imalka Jayawardena, K. D. G.; Cox, David C.; Clarkson, Guy J.; Walton, Richard I.; Le-Quang, Long; Chauvin, Jerôme; Silva, S. Ravi P.; Demets, Grégoire Jean-François

    2017-01-01

    Metal–organic frameworks (MOFs) have emerged as an exciting class of porous materials that can be structurally designed by choosing particular components according to desired applications. Despite the wide interest in and many potential applications of MOFs, such as in gas storage, catalysis, sensing and drug delivery, electrical semiconductivity and its control is still rare. The use and fabrication of electronic devices with MOF-based components has not been widely explored, despite signifi...

  7. Low concentration CO2 capture using physical adsorbents: Are Metal-Organic Frameworks becoming the new benchmark materials?

    KAUST Repository

    Belmabkhout, Youssef

    2016-03-30

    The capture and separation of traces and concentrated CO2 from important commodities such as CH4, H2, O2 and N2, is becoming important in many areas related to energy security and environmental sustainability. While trace CO2 concentration removal applications have been modestly studied for decades, the spike in interest in the capture of concentrated CO2 was motivated by the need for new energy vectors to replace highly concentrated carbon fuels and the necessity to reduce emissions from fossil fuel-fired power plants. CO2 capture from various gas streams, at different concentrations, using physical adsorbents, such as activated carbon, zeolites, and metal-organic frameworks (MOFs), is attractive. However, the adsorbents must be designed with consideration of many parameters including CO2 affinity, kinetics, energetics, stability, capture mechanism, in addition to cost. Here, we perform a systematic analysis regarding the key technical parameters that are required for the best CO2 capture performance using physical adsorbents. We also experimentally demonstrate a suitable material model of Metal Organic Framework as advanced adsorbents with unprecedented properties for CO2 capture in a wide range of CO2 concentration. These recently developed class of MOF adsorbents represent a breakthrough finding in the removal of traces CO2 using physical adsorption. This platform shows colossal tuning potential for more efficient separation agents.

  8. Selective binding of O(2) over N(2) in a redox-active metal-organic framework with open iron(II) coordination sites

    NARCIS (Netherlands)

    Bloch, E.D.; Murray, L.J.; Queen, W.L.; Chavan, S.; Maximoff, S.N.; Bigi, J.P.; Krishna, R.; Peterson, V.K.; Grandjean, F.; Smit, B.; Long, G.J.; Bordiga, S.; Brown, C.M.; Long, J.R.

    2011-01-01

    The air-free reaction between FeCl2 and H4dobdc (dobdc4- = 2,5-dioxido-1,4-benzenedicarboxylate) in a mixture of N,N-dimethylformamide (DMF) and methanol affords Fe2(dobdc)·4DMF, a metal-organic framework adopting the MOF-74 (or CPO-27) structure type. The desolvated form of this material displays a

  9. Synthesis and Structural Characterization of Carboxylate-Based Metal-Organic Frameworks and Coordination Networks

    Science.gov (United States)

    Calderone, Paul

    Coordination networks (CNs) and metal-organic frameworks (MOFs) are crystalline materials composed of metal ions linked by multifunctional organic ligands. From these connections, infinite arrays of one-, two-, or three-dimensional networks can be formed. Exploratory synthesis and research of novel CNs and MOFs is of current interest because of their many possible industrial applications including gas storage, catalysis, magnetism, and luminescence. A variety of metal centers and organic ligands can be used to synthesize MOFs and CNs under a range of reaction conditions, leading to extraordinary structural diversity. The characteristics of the metals and linkers, such as properties and coordination preferences, play the biggest role in determining the structure and properties of the resulting network. Thus, the choice of metal and linker is dictated by the desired traits of the target network. The pervasive use of transition metal centers in MOF synthesis stems from their well-known coordination behavior with carboxylate-based linkers, thus facilitating design strategies. Conversely, CNs and MOFs based on s-block and lanthanide metals are less studied because each group presents unique challenges to structure prediction. Lanthanide metals have variable coordination spheres capable of accommodating up to twelve atoms, while the bonding in s-block metals takes on a mainly ionic character. In spite of these obstacles, lanthanide and s-block CNs are worthwhile synthetic targets because of their unique properties. Interesting photoluminescent and sensing materials can be developed using lanthanide metals, whereas low atomic weight s-block metals may afford an advantage in gravimetric advantages for gas storage applications. The aim of this research was to expand the current understanding of carboxylate-based CN and MOF synthesis by varying the metals, solvents, and temperatures used. To this end, magnesium-based CNs were examined using a variety of aromatic carboxylate

  10. Single-Crystal to Single-Crystal Transformation of a Nonporous Fe(II) Metal-Organic Framework into a Porous Metal-Organic Framework via a Solid-State Reaction.

    Science.gov (United States)

    Spirkl, Sebastian; Grzywa, Maciej; Reschke, Stephan; Fischer, Jonas K H; Sippel, Pit; Demeshko, Serhiy; Krug von Nidda, Hans-Albrecht; Volkmer, Dirk

    2017-10-16

    We report the synthesis of an air-stable nonporous coordination compound based on iron(II) centers, formate anions, and a 4,4'-bipyrazole (H 2 BPZ) ligand. Upon thermal treatment, a porous metal-organic framework (MOF) formed due to decomposition of the incorporated formate anions. This decomposition step and the following structural changes constituted a single-crystal to single-crystal transformation. The resulting [Fe(BPZ)] framework contained tetrahedrally coordinated iron(II) metal centers. The framework was sensitive toward oxidation by molecular oxygen even at temperatures of 183 K, as followed by oxygen sorption measurements and a color change from colorless to metallic black. The semiconductor properties of the oxidized material were studied by diffuse reflectance UV/vis/NIR spectroscopy and dielectric spectroscopy.

  11. A 3D Ag(I) metal-organic framework for sensing luminescence and photocatalytic activities

    Science.gov (United States)

    Chang, Hai-Ning; Liu, Li-Wei; Hao, Zeng Chuan; Cui, Guang-Hua

    2018-03-01

    A fluorescent metal-organic framework (MOF), [Ag(btx)0.5(DCTP)0.5]n (1) (H2DCTP = 2,5-dichloroterephthalic acid and btx = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene) has been hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, powder X-ray diffractions and thermogravimetry. The framework of 1 can be classified as a binodal (4,4)-connected PtS topological network. The fluorescence explorations demonstrated that 1 shows selective and sensitive detection towards Cr2O72- with high quenching efficiency of 1.92 × 104 M-1. The rapid and efficient response of 1 to Cr2O72- ion suggests that this material could be used as a luminescent sensor for Cr2O72- ion. Meanwhile the photocatalytic properties of 1 for the degradation of RhB have also been investigated under UV radiation. The possible photocatalytic mechanisms were also speculated. Hence, 1 can become multi-functional material in sensitive detection and effective removal of some environment pollutants in industrial waste water solutions.

  12. CFA-4 - a fluorinated metal-organic framework with exchangeable interchannel cations.

    Science.gov (United States)

    Fritzsche, J; Grzywa, M; Denysenko, D; Bon, V; Senkovska, I; Kaskel, S; Volkmer, D

    2017-05-23

    The syntheses and crystal structures of the fluorinated linker 1,4-bis(3,5-bis(trifluoromethyl)-1H-pyrazole-4-yl)benzene (H 2 -tfpb; 1) and the novel metal-organic framework family M[CFA-4] (Coordination Framework Augsburg University-4), M[Cu 5 (tfpb) 3 ] (M = Cu(i), K, Cs, Ca(0.5)), are described. The ligand 1 is fully characterized by single crystal X-ray diffraction, photoluminescence-, NMR-, IR spectroscopy, and mass spectrometry. The copper(i)-containing MOF crystallizes in the hexagonal crystal system within the chiral space group P6 3 22 (no. 182) and the unit cell parameters are as follows: a = 23.630(5) Å, c = 41.390(5) Å, V = 20 015(6) Å 3 . M[CFA-4] features a porous 3-D structure constructed from pentanuclear copper(i) secondary building units {Cu(pz) 6 } - (pz = pyrazolate). Cu(I)[CFA-4] is fully characterized by synchrotron single crystal X-ray diffraction, thermogravimetric analysis, variable temperature powder X-ray diffraction, IR spectroscopy, photoluminescence and gas sorption measurements. Moreover, thermal stability and gas sorption properties of K[CFA-4] and Cu(I)[CFA-4] are compared.

  13. Ion conductivity and transport by porous coordination polymers and metal-organic frameworks.

    Science.gov (United States)

    Horike, Satoshi; Umeyama, Daiki; Kitagawa, Susumu

    2013-11-19

    Ion conduction and transport in solids are both interesting and useful and are found in widely distinct materials, from those in battery-related technologies to those in biological systems. Scientists have approached the synthesis of ion-conductive compounds in a variety of ways, in the areas of organic and inorganic chemistry. Recently, based on their ion-conducting behavior, porous coordination polymers (PCPs) and metal-organic frameworks (MOFs) have been recognized for their easy design and the dynamic behavior of the ionic components in the structures. These PCP/MOFs consist of metal ions (or clusters) and organic ligands structured via coordination bonds. They could have highly concentrated mobile ions with dynamic behavior, and their characteristics have inspired the design of a new class of ion conductors and transporters. In this Account, we describe the state-of-the-art of studies of ion conductivity by PCP/MOFs and nonporous coordination polymers (CPs) and offer future perspectives. PCP/MOF structures tend to have high hydrophilicity and guest-accessible voids, and scientists have reported many water-mediated proton (H(+)) conductivities. Chemical modification of organic ligands can change the hydrated H(+) conductivity over a wide range. On the other hand, the designable structures also permit water-free (anhydrous) H(+) conductivity. The incorporation of protic guests such as imidazole and 1,2,4-triazole into the microchannels of PCP/MOFs promotes the dynamic motion of guest molecules, resulting in high H(+) conduction without water. Not only the host-guest systems, but the embedding of protic organic groups on CPs also results in inherent H(+) conductivity. We have observed high H(+) conductivities under anhydrous conditions and in the intermediate temperature region of organic and inorganic conductors. The keys to successful construction are highly mobile ionic species and appropriate intervals of ion-hopping sites in the structures. Lithium (Li

  14. High proton conductivity in cyanide-bridged metal-organic frameworks: understanding the role of water

    NARCIS (Netherlands)

    Gao, Y.; Broersen, R.; Hageman, W.; Yan, N.; Mittelmeijer-Hazeleger, M.; Rothenberg, G.; Tanase, S.

    2015-01-01

    We investigate and discuss the proton conductivity properties of the cyanide-bridged metal–organic framework (MOF) [Nd(mpca)2Nd(H2O)6Mo(CN)8]·nH2O (where mpca is 5-methyl-2-pyrazinecarboxylate). This MOF is one of an exciting class of cyanide-bridged materials that can combine porosity with

  15. Method for analyzing structural changes of flexible metal-organic frameworks induced by adsorbates

    NARCIS (Netherlands)

    Dubbeldam, D.; Krishna, R.; Snurr, R.Q.

    2009-01-01

    Metal−organic frameworks (MOFs) have crystal structures that exhibit unusual flexibility. An extreme example is that of the "breathing MOF" MIL-53 that expands or shrinks to admit guest molecules like CO2 and water. We present a powerful simulation tool to quickly calculate unit cell shape and size

  16. Design of Laccase-Metal Organic Framework-Based Bioelectrodes for Biocatalytic Oxygen Reduction Reaction.

    Science.gov (United States)

    Patra, Snehangshu; Sene, Saad; Mousty, Christine; Serre, Christian; Chaussé, Annie; Legrand, Ludovic; Steunou, Nathalie

    2016-08-10

    Laccase in combination with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as a mediator is a well-known bioelectrocatalyst for the 4-electron oxygen reduction reactions (ORR). The present work deals with the first exploitation of mesoporous iron(III) trimesate-based metal organic frameworks (MOF) MIL-100(Fe) (MIL stands for materials from Institut Lavoisier) as a new and efficient immobilization matrix of laccase for the building up of biocathodes for ORR. First, the immobilization of ABTS in the pores of the MOF was studied by combining micro-Raman spectroscopy, X-ray powder diffraction (XRPD), and N2 porosimetry. The ABTS-MIL-100(Fe)-based modified electrode presents excellent properties in terms of charge transfer kinetics and ionic conductivity as well as a very stable and reproducible electrochemical response, showing that MIL-100(Fe) provides a suitable and stabilizing microenvironment for electroactive ABTS molecules. In a second step, laccase was further immobilized on the MIL-100(Fe)-ABTS matrix. The Lac-ABTS-MIL-100(Fe)-CIE bioelectrode presents a high electrocatalytic current density of oxygen reduction and a reproducible electrochemical response characterized by a high stability over a long period of time (3 weeks). These results constitute a significant advance in the field of laccase-based bioelectrocatalysts for ORR. According to our work, it appears that the high catalytic efficiency of Lac-ABTS-MIL-100(Fe) for ORR may result from a synergy of chemical and catalytic properties of MIL-100(Fe) and laccase.

  17. In-growth metal organic framework/synthetic hybrids as antimicrobial fabrics and its toxicity.

    Science.gov (United States)

    Emam, Hossam E; Darwesh, Osama M; Abdelhameed, Reda M

    2018-05-01

    Bio-active synthetic fabrics based on polyester (PET) and Nylon were manufactured by in-situ formation of Cu-BTC metal organic framework (MOF). In-growth of Cu-BTC within fabrics was accomplished in one pot simple process. The scanning microscope, X-ray diffraction and infrared spectra were all confirmed the formation of Cu-BTC within fabrics structure and reflected the role of fabrics' building unit in the Cu-BTC preparation. The estimated contents of materials onto fabrics were ranged in 97.14-127.33 mg MOF/g fabric and 30.59-40.10 mg Cu/g fabric. After embracing with Cu-BTC, color of fabrics was transformed to greenish-blue. The so-produced Cu-BTC/fabric hybrids were exhibited good biological activities against three different microbial pathogens (E. coli, S. aureus and C. albicans). The minimal inhibitory concentrations from the residual Cu-BTC powder were 65-70, 60-64 and 62-67 mg/mL, for S. aureus, E. coli and C. albicans pathogens, respectively, which were similar to that reported for commercial Cu-BTC. Moreover, no toxicity was observably detected for the released Cu-BTC from fabrics against brine shrimp at 10 mg/mL. These results revealed that, the in-growth of Cu-BTC resulted in production of biocidal synthetic fabrics without any ecotoxic effects at the as-used Cu-BTC content. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Surfactant media to grow new crystalline cobalt 1,3,5-benzenetricarboxylate metal-organic frameworks

    KAUST Repository

    Lu, Haisheng

    2014-08-18

    In this report, three new metal-organic frameworks (MOFs), [Co 3(μ3-OH)(HBTC)(BTC)2Co(HBTC)]·(HTEA) 3·H2O (NTU-Z30), [Co(BTC)] ·HTEA·H2O (NTU-Z31), [Co3(BTC) 4]·(HTEA)4 (NTU-Z32), where H3BTC = 1,3,5-benzenetricarboxylic acid, TEA = triethylamine, and NTU = Nanyang Technological University, have been successfully synthesized under surfactant media and have been carefully characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, and IR spectromtry. NTU-Z30 has an unusual trimeric [Co3(μ3-OH)(COO) 7] secondary building unit (SBU), which is different from the well-known trimeric [Co3O(COO)6] SBU. The topology studies indicate that NTU-Z30 and NTU-Z32 possess two new topologies, 3,3,6,7-c net and 2,8-c net, respectively, while NTU-Z31 has a known topology rtl type (3,6-c net). Magnetic analyses show that all three materials have weak antiferromagnetic behavior. Furthermore, NTU-Z30 has been selected as the heterogeneous catalyst for the aerobic epoxidation of alkene, and our results show that this material exhibits excellent catalytic activity as well as good stability. Our success in growing new crystalline cobalt 1,3,5- benzenetricarboxylate MOFs under surfactant media could pave a new road to preparing new diverse crystalline inorganic materials through a surfactant-thermal method. © 2014 American Chemical Society.

  19. Four Mixed-Ligand Zn(II Three-Dimensional Metal-Organic Frameworks: Synthesis, Structural Diversity, and Photoluminescent Property

    Directory of Open Access Journals (Sweden)

    Chih-Chieh Wang

    2017-11-01

    Full Text Available Assemblies of four three-dimensional (3D mixed-ligand coordination polymers (CPs having formulas, {[Zn2(bdc2(4-bpdh]·C2H5OH·2H2O}n (1, [Zn(bdc(4-bpdh]n (2, {[Zn2(bdc2(4-bpdh2]·(4-bpdh}n (3, and {[Zn(bdc(4-bpdh]·C2H5OH}n (4 (bdc2− = dianion of 1,4-benzenedicarboxylic acid, 4-bpdh = 2,5-bis(4-pyridyl-3,4-diaza-2,4-hexadiene have been synthesized and structurally characterized by single-crystal X-ray diffraction method. Structural determination reveals that the coordination numbers (geometry of Zn(II ions in 1, 2, 3, and 4 are five (distorted square-pyramidal (SP, six (distorted octahedral (Oh, five (trigonal-bipyramidal (TBP, and four (tetrahedral (Td, respectively, and are bridged by 4-bpdh with bis-monodentate coordination mode and bdc2− ligands with bis-bidentate in 1, chelating/bidentate in 2, bis-monodentate and bis-bidentate in 3, and bis-monodentate in 4, to generate two-fold interpenetrating 3D cube-like metal-organic framework (MOF with pcu topology, non-interpenetrating 3D MOF, two-fold interpenetrating 3D rectangular-box-like MOF with pcu topology and five-fold interpenetrating diamondoid-like MOF with dia topology, respectively. These different intriguing architectures indicate that the coordination numbers and geometries of Zn(II ions, coordination modes of bdc2− ligand, and guest molecules play important roles in the construction of MOFs and the formation of the structural topologies and interpenetrations. Thermal stabilities, and photoluminescence study of 1–4 were also studied in detail. The complexes exhibit ligands based photoluminescence properties at room temperature.

  20. Fabrication of highly co2 selective metal organic framework membrane using liquid phase epitaxy approach

    KAUST Repository

    Eddaoudi, Mohamed

    2016-01-28

    Embodiments include a method of making a metal organic framework membrane comprising contacting a substrate with a solution including a metal ion and contacting the substrate with a solution including an organic ligand, sufficient to form one or more layers of a metal organic framework on a substrate. Embodiments further include a defect-free metal organic framework membrane comprising MSiF6(pyz)2, wherein M is a metal, wherein the thickness of the membrane is less than 1,000 µm, and wherein the metal organic has a growth orientation along the [110] plane relative to a substrate.

  1. Humidity Detection Using Metal Organic Framework Coated on QCM

    KAUST Repository

    Kosuru, Lakshmoji

    2016-06-28

    Quartz crystal microbalance (QCM) coated with poly-4-vinylpyridine (PVP) and metal organic framework HKUST-1 are investigated and compared for humidity sensing. Drop casting method is employed to coat the PVP and HKUST-1 solutions onto the surface of a quartz crystal microbalance. The resonance frequencies of these sensors with varying relative humidity (RH) from 22% RH to 69% RH are measured using impedance analysis method. The sensitivity, humidity hysteresis, response, and recovery times of these sensors are studied. The sensitivities of uncoated, PVP, and HKUST-1 coated QCM sensors are 7 Hz, 48 Hz, and 720 Hz, respectively, in the range of 22% RH–69% RH. The extraction of desorption rate and adsorption energy associated with the adsorption and desorption of water molecules on these surfaces reveals that HKUST-1 has better sensing properties than PVP and uncoated QCM sensors. In this work, the HKUST-1 coated QCM is shown to be a promising material for moisture detection.

  2. Humidity Detection Using Metal Organic Framework Coated on QCM

    Directory of Open Access Journals (Sweden)

    Lakshmoji Kosuru

    2016-01-01

    Full Text Available Quartz crystal microbalance (QCM coated with poly-4-vinylpyridine (PVP and metal organic framework HKUST-1 are investigated and compared for humidity sensing. Drop casting method is employed to coat the PVP and HKUST-1 solutions onto the surface of a quartz crystal microbalance. The resonance frequencies of these sensors with varying relative humidity (RH from 22% RH to 69% RH are measured using impedance analysis method. The sensitivity, humidity hysteresis, response, and recovery times of these sensors are studied. The sensitivities of uncoated, PVP, and HKUST-1 coated QCM sensors are 7 Hz, 48 Hz, and 720 Hz, respectively, in the range of 22% RH–69% RH. The extraction of desorption rate and adsorption energy associated with the adsorption and desorption of water molecules on these surfaces reveals that HKUST-1 has better sensing properties than PVP and uncoated QCM sensors. In this work, the HKUST-1 coated QCM is shown to be a promising material for moisture detection.

  3. Symbiosis of zeolite-like metal-organic frameworks (rho-ZMOF) and hydrogels: Composites for controlled drug release

    KAUST Repository

    Ananthoji, Ramakanth

    2011-01-01

    The design and synthesis of new finely tunable porous materials has spurred interest in developing novel uses in a variety of systems. Zeolites, inorganic materials with high thermal and mechanical stability, in particular, have been widely examined for use in applications such as catalysis, ion exchange and separation. A relatively new class of inorganic-organic hybrid materials known as metal-organic frameworks (MOFs) have recently surfaced, and many have exhibited their efficiency in potential applications such as ion exchange and drug delivery. A more recent development is the design and synthesis of a subclass of MOFs based on zeolite topologies (i.e. ZMOFs), which often exhibit traits of both zeolites and MOFs. Bio-compatible hydrogels already play an important role in drug delivery systems, but are often limited by stability issues. Thus, the addition of ZMOFs to hydrogel formulations is expected to enhance the hydrogel mechanical properties, and the ZMOF-hydrogel composites should present improved, symbiotic drug storage and release for delivery applications. Herein we present the novel composites of a hydrogel with a zeolite-like metal-organic framework, rho-ZMOF, using 2-hydroxyethyl methacrylate (HEMA), 2,3-dihydroxypropyl methacrylate (DHPMA), N-vinyl-2-pyrolidinone (VP) and ethylene glycol dimethacrylate (EGDMA), and the corresponding drug release. An ultraviolet (UV) polymerization method is employed to synthesize the hydrogels, VP 0, VP 15, VP 30, VP 45 and the ZMOF-VP 30 composite, by varying the VP content (mol%). The rho-ZMOF, VP 30, and ZMOF-VP 30 composite are all tested for the controlled release of procainamide (protonated, PH), an anti-arrhythmic drug, in phosphate buffer solution (PBS) using UV spectroscopy. © 2011 The Royal Society of Chemistry.

  4. Green methods for preparing highly co2 selective and h2s tolerant metal organic frameworks

    KAUST Repository

    Eddaoudi, Mohamed

    2015-12-23

    A green route for preparing a metal organic framework include mixing metal precursor with a ligand precursor to form a solvent-free mixture; adding droplets of water to the mixture; heating the mixture at a first temperature after adding the water; and isolating the metal organic framework material including the metal and the ligand.

  5. Investigating the gas sorption mechanism in an rht -metal-organic framework through computational studies

    KAUST Repository

    Pham, Tony T.

    2014-01-09

    Grand canonical Monte Carlo (GCMC) simulations were performed to investigate CO2 and H2 sorption in an rht-metal-organic framework (MOF) that was synthesized with a ligand having a nitrogen-rich trigonal core through trisubstituted triazine groups and amine functional groups. This MOF was synthesized by two different groups, each reporting their own distinct gas sorption measurements and crystal structure. Electronic structure calculations demonstrated that the small differences in the atomic positions between each group\\'s crystal structure resulted in different electrostatic parameters about the Cu2+ ions for the respective unit cells. Simulations of CO2 sorption were performed with and without many-body polarization effects and using our recently developed CO2 potentials, in addition to a well-known bulk CO2 model, in both crystallographic unit cells. Simulated CO2 sorption isotherms and calculated isosteric heats of adsorption, Qst, values were in excellent agreement with the results reported previously by Eddaoudi et al. for both structures using the polarizable CO2 potential. For both crystal structures, the initial site for CO2 sorption were the Cu 2+ ions that had the higher positive charge in the unit cell, although the identity of this electropositive Cu2+ ion was different in each case. Simulations of H2 sorption were performed with three different hydrogen potentials of increasing anisotropy in both crystal structures and the results, especially with the highest fidelity model, agreed well with Eddaoudi et al.\\'s experimental data. The preferred site of H 2 sorption at low loading was between two Cu2+ ions of neighboring paddlewheels. The calculation of the normalized hydrogen dipole distribution for the polarizable model in both crystal structures aided in the identification of four distinct sorption sites in the MOF, which is consistent to what was observed in the experimental inelastic neutron scattering (INS) spectra. Lastly, while the

  6. Pyrolytic in situ magnetization of metal-organic framework MIL-100 for magnetic solid-phase extraction.

    Science.gov (United States)

    Huo, Shu-Hui; An, Hai-Yan; Yu, Jing; Mao, Xue-Feng; Zhang, Zhe; Bai, Lei; Huang, Yan-Feng; Zhou, Peng-Xin

    2017-09-29

    In this study, we report a facile, environmental friendly fabrication of a type of magnetic metal-organic framework (MOF) MIL-100 that can be used for magnetic solid-phase extraction (MSPE). The magnetic MOF composites were fabricated using in situ calcination method. The as-synthesized materials exhibited both high porosity and magnetic characteristics. They used for the MSPE of polycyclic aromatic hydrocarbons (PAHs) from water samples. Such MOF-based magnetic solid-phase extraction in combination with gas chromatography equipped with a flame ionization detector (GC-FID), exhibited wide linearity (0.02-250μgL -1 ), low detection limits (4.6-8.9ngL -1 ), and high enrichment factors (452-907) for PAHs. The relative standard deviations (RSDs) for intra- and inter-day extractions of PAHs were ranging from 1.7% to 9.8% and 3.8% to 9.2%, respectively. The recoveries for spiked PAHs (1μgL -1 ) in water samples were in the range of 88.5% to 106.6%. The results showed that the special anion-π orbital (electron donor-acceptor) interaction and π-π stacking between magnetic MIL-100 and PAHs play an important role in the adsorption of PAHs. Copyright © 2017. Published by Elsevier B.V.

  7. Exploring Charge Transport in Guest Molecule Infiltrated Cu3(BTC)2 Metal Organic Framework

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Francois Leonard [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Stavila, Vitalie [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Allendorf, Mark D. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2014-09-01

    The goal of this Exploratory Express project was to expand the understanding of the physical properties of our recently discovered class of materials consisting of metal-organic frameworks with electroactive ‘guest’ molecules that together form an electrically conducting charge-transfer complex (molecule@MOF). Thin films of Cu3(BTC)2 were grown on fused silica using solution step-by-step growth and were infiltrated with the molecule tetracyanoquinodimethane (TCNQ). The infiltrated MOF films were extensively characterized using optical microscopy, scanning electron microscopy, Raman spectroscopy, electrical conductivity, and thermoelectric properties. Thermopower measurements on TCNQ@Cu3(BTC)2 revealed a positive Seebeck coefficient of ~400 μV/k, indicating that holes are the primary carriers in this material. The high value of the Seebeck coefficient and the expected low thermal conductivity suggest that molecule@MOF materials may be attractive for thermoelectric power conversion applications requiring low cost, solution-processable, and non-toxic active materials.

  8. Hierarchical Nanostructures of Metal-Organic Frameworks Applied in Gas Separating ZIF-8-on-ZIF-67 Membranes.

    Science.gov (United States)

    Knebel, Alexander; Wulfert-Holzmann, Paul; Friebe, Sebastian; Pavel, Janet; Strauß, Ina; Mundstock, Alexander; Steinbach, Frank; Caro, Jürgen

    2018-02-02

    Membranes from metal-organic frameworks (MOFs) are highly interesting for industrial gas separation applications. Strongly improved performances for carbon capture and H 2 purification tasks in MOF membranes are obtained by using highly reproducable and very accuratly, hierarchically grown ZIF-8-on-ZIF-67 (ZIF-8@ZIF-67) nanostructures. To forgo hardly controllable solvothermal synthesis, particles and layers are prepared by self-assembling methods. It was possible for the first time to confirm ZIF-8-on-ZIF-67 membrane growth on rough and porous ceramic supports using the layer-by-layer deposition. Additionally, hierarchical particles are made in a fast RT synthesis with high monodispersity. Characterization of the hierarchical and epitaxial grown layers and particles is performed by SEM, TEM, EDXM and gas permeation. The system ZIF-8@ZIF-67 shows a nearly doubled H 2 /CO 2 separation factor, regardless of whether neat membrane or mixed-matrix-membrane in comparison to other MOF materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Reversible Capture and Release of Cl2 and Br2 with a Redox-Active Metal-Organic Framework.

    Science.gov (United States)

    Tulchinsky, Yuri; Hendon, Christopher H; Lomachenko, Kirill A; Borfecchia, Elisa; Melot, Brent C; Hudson, Matthew R; Tarver, Jacob D; Korzyński, Maciej D; Stubbs, Amanda W; Kagan, Jacob J; Lamberti, Carlo; Brown, Craig M; Dincă, Mircea

    2017-04-26

    Extreme toxicity, corrosiveness, and volatility pose serious challenges for the safe storage and transportation of elemental chlorine and bromine, which play critical roles in the chemical industry. Solid materials capable of forming stable nonvolatile compounds upon reaction with elemental halogens may partially mitigate these challenges by allowing safe halogen release on demand. Here we demonstrate that elemental halogens quantitatively oxidize coordinatively unsaturated Co(II) ions in a robust azolate metal-organic framework (MOF) to produce stable and safe-to-handle Co(III) materials featuring terminal Co(III)-halogen bonds. Thermal treatment of the oxidized MOF causes homolytic cleavage of the Co(III)-halogen bonds, reduction to Co(II), and concomitant release of elemental halogens. The reversible chemical storage and thermal release of elemental halogens occur with no significant losses of structural integrity, as the parent cobaltous MOF retains its crystallinity and porosity even after three oxidation/reduction cycles. These results highlight a material operating via redox mechanism that may find utility in the storage and capture of other noxious and corrosive gases.

  10. A nanoscale Zr-based fluorescent metal-organic framework for selective and sensitive detection of hydrogen sulfide

    Science.gov (United States)

    Li, Yanping; Zhang, Xin; Zhang, Ling; Jiang, Ke; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2017-11-01

    Hydrogen sulfide (H2S) has been commonly viewed as a gas signaling molecule in various physiological and pathological processes. However, the highly efficient H2S detection still remains challenging. Herein, we designed a new robust nano metal-organic framework (MOF) UiO-66-CH=CH2 as a fluorescent probe for rapid, sensitive and selective detection of biological H2S. UiO-66-CH=CH2 was prepared by heating ZrCl4 and 2-vinylterephthalic acid via a simple method. UiO-66-CH=CH2 displayed fluorescence quenching to H2S and kept excellent selectivity in the presence of biological relevant analytes especially the cysteine and glutathione. This MOF-based probe also exhibited fast response (10 s) and high sensitivity with a detection limit of 6.46 μM which was within the concentration range of biological H2S in living system. Moreover, this constructed MOF featured water-stability, nanoscale (20-30 nm) and low toxicity, which made it a promising candidate for biological H2S sensing.

  11. A New Synthetic Route to Microporous Silica with Well-Defined Pores by Replication of a Metal-Organic Framework.

    Science.gov (United States)

    Kondo, Atsushi; Hall, Anthony Shoji; Mallouk, Thomas E; Maeda, Kazuyuki

    2015-08-17

    Microporous amorphous hydrophobic silica materials with well-defined pores were synthesized by replication of the metal-organic framework (MOF) [Cu3 (1,3,5-benzenetricarboxylate)2 ] (HKUST-1). The silica replicas were obtained by using tetramethoxysilane or tetraethoxysilane as silica precursors and have a micro-meso binary pore system. The BET surface area, the micropore volume, and the mesopore volume of the silica replica, obtained by means of hydrothermal treatment at 423 K with tetraethoxysilane, are 620 m(2) g(-1) , 0.18 mL g(-1) , and 0.55 mL g(-1) , respectively. Interestingly, the silica has micropores with a pore size of 0.55 nm that corresponds to the pore-wall thickness of the template MOF. The silica replica is hydrophobic, as confirmed by adsorption analyses, although the replica has a certain amount of silanol groups. This hydrophobicity is due to the unique condensation environment of the silica precursors in the template MOF. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. In situ biosynthesis of ultrafine metal nanoparticles within a metal-organic framework for efficient heterogeneous catalysis

    Science.gov (United States)

    Tang, Lei; Shi, Jiafu; Wu, Hong; Zhang, Shaohua; Liu, Hua; Zou, Hongjian; Wu, Yizhou; Zhao, Jingjing; Jiang, Zhongyi

    2017-09-01

    The synthesis of ultrafine, uniform, well-dispersed functional nanoparticles (NPs) under mild conditions in a controlled manner remains a great challenge. In biological systems, a well-defined biomineralization process is exploited, in which the control over NPs’ size, shape and distribution is temporally and spatially regulated by a variety of biomolecules in a confined space. Inspired by this, we embedded proteins into metal-organic frameworks (MOFs) and explored a novel approach to synthesize metallic NPs by taking the synergy of protein-induced biomineralization process and space-confined effect of MOFs. The generation and growth of ultrafine metal NPs (Ag or Au) was induced by the entrapped lysozyme molecules and confined by the ZIF-8 pores. Due to the narrow size distribution and homogeneous spatial distribution of metal NPs, the as-synthesized NPs exhibit remarkably elevated catalytic activity. These findings demonstrate that MOFs can be loaded with specific proteins to selectively deposit inorganic NPs via biomimetic mineralization and these novel kinds of nanohybrid materials may find applications in catalysis, sensing and optics.

  13. Multivariate Metal-Organic Frameworks for Dialing-in the Binding and Programming the Release of Drug Molecules.

    Science.gov (United States)

    Dong, Zhiyue; Sun, Yangzesheng; Chu, Jun; Zhang, Xianzheng; Deng, Hexiang

    2017-10-11

    We report the control of guest release profiles by dialing-in desirable interactions between guest molecules and pores in metal-organic frameworks (MOFs). The interactions can be derived by the rate constants that were quantitatively correlated with the type of functional group and its proportion in the porous structure; thus the release of guest molecules can be predicted and programmed. Specifically, three probe molecules (ibuprofen, rhodamine B, and doxorubicin) were studied in a series of robust and mesoporous MOFs with multiple functional groups [MIL-101(Fe)-(NH 2 ) x , MIL-101(Fe)-(C 4 H 4 ) x , and MIL-101(Fe)-(C 4 H 4 ) x (NH 2 ) 1-x ]. The release rate can be adjusted by 32-fold [rhodamine from MIL-101(Fe)-(NH 2 ) x ], and the time of release peak can be shifted by up to 12 days over a 40-day release period [doxorubicin from MIL-101(Fe)-(C 4 H 4 ) x (NH 2 ) 1-x ], which was not obtained in the physical mixture of the single component MOF counterparts nor in other porous materials. The corelease of two pro-drug molecules (ibuprofen and doxorubicin) was also achieved.

  14. A Metal-Organic-Framework-Based Electrolyte with Nanowetted Interfaces for High-Energy-Density Solid-State Lithium Battery.

    Science.gov (United States)

    Wang, Ziqi; Tan, Rui; Wang, Hongbin; Yang, Luyi; Hu, Jiangtao; Chen, Haibiao; Pan, Feng

    2018-01-01

    Solid-state batteries (SSBs) are promising for safer energy storage, but their active loading and energy density have been limited by large interfacial impedance caused by the poor Li + transport kinetics between the solid-state electrolyte and the electrode materials. To address the interfacial issue and achieve higher energy density, herein, a novel solid-like electrolyte (SLE) based on ionic-liquid-impregnated metal-organic framework nanocrystals (Li-IL@MOF) is reported, which demonstrates excellent electrochemical properties, including a high room-temperature ionic conductivity of 3.0 × 10 -4 S cm -1 , an improved Li + transference number of 0.36, and good compatibilities against both Li metal and active electrodes with low interfacial resistances. The Li-IL@MOF SLE is further integrated into a rechargeable Li|LiFePO 4 SSB with an unprecedented active loading of 25 mg cm -2 , and the battery exhibits remarkable performance over a wide temperature range from -20 up to 150 °C. Besides the intrinsically high ionic conductivity of Li-IL@MOF, the unique interfacial contact between the SLE and the active electrodes owing to an interfacial wettability effect of the nanoconfined Li-IL guests, which creates an effective 3D Li + conductive network throughout the whole battery, is considered to be the key factor for the excellent performance of the SSB. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Pillar-Layered Metal-Organic Framework with Sieving Effect and Pore Space Partition for Effective Separation of Mixed Gas C2H2/C2H4.

    Science.gov (United States)

    Hong, Xu-Jia; Wei, Qin; Cai, Yue-Peng; Wu, Bing-Bing; Feng, Hai-Xing; Yu, Ying; Dong, Ren-Feng

    2017-08-30

    The removal of acetylene from the industrial feed gas to purify the ethylene is an important and challenging issue. The adsorption-based separation is a more environmentally friendly and cost-effective method compared to the current removal approaches such as partial hydrogenation and solvent extraction, while facing the challenge of developing materials with high C 2 H 2 /C 2 H 4 selectivity and C 2 H 2 capacity. Herein, by expanding mixed-metal organic frameworks (M'MOFs) structure with high C 2 H 2 /C 2 H 4 selectivity, we report a pillar-layered MOF, {[Cd 5 (MPCZ) 2 (BDC) 3 (NO 3 ) 2 (H 2 O) 4 ]·G} n (MECS-5), which not only inherits the sieving effects of M'MOF series but also develops its own characteristic-the 2D layer with expanding space and the plane pore-partition group to "cover" it. MECS-5 shows higher ideal adsorption solution theory C 2 H 2 /C 2 H 4 selectivity than the most reported MOFs, especially more than 5 times higher than MOF-74 series while displaying great enhancement in the C 2 H 2 capacity, more than 2 times higher compared to the M'MOF. The column breakthrough experiment further proves the possibility of MECS-5a for real industrial ethylene purification.

  16. Synthesis of nanoporous carbohydrate metal-organic framework and encapsulation of acetaldehyde

    Science.gov (United States)

    Al-Ghamdi, Saleh; Kathuria, Ajay; Abiad, Mohamad; Auras, Rafael

    2016-10-01

    Gamma cyclodextrin (γ-CD) metal organic frameworks (CDMOFs) were synthesized by coordinating γ-CDs with potassium hydroxide (KOH), referred hereafter as CDMOF-a, and potassium benzoate (C7H5KO2), denoted as CDMOF-b. The obtained CDMOF structures were characterized using nitrogen sorption isotherm, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). High surface areas were achieved by the γ-CD based MOF structures where the Langmuir specific surface areas (SSA) of CDMOF-a and CDMOF-b were determined as 1376 m2 g-1 and 607 m2 g-1; respectively. The dehydrated CDMOF structures demonstrated good thermal stability up to 250 °C as observed by the TGA studies. XRD results for CDMOF-a and CDMOF-b reveal a body centered-cubic (BCC) and trigonal crystal system; respectively. Due to its accessible porous structure and high surface area, acetaldehyde was successfully encapsulated in CDMOF-b. During the release kinetic studies, we observed peak release of 53 μg of acetaldehyde per g of CDMOF-b, which was 100 times greater than previously reported encapsulation in β-CD. However, aldol condensation reaction occurred during encapsulation of acetaldehyde into CDMOF-a. This research work demonstrates the potential to encapsulate volatile organic compounds in CDMOF-b, and their associated release for applications including food, pharmaceuticals and packaging.

  17. Elucidating the mechanism responsible for anomalous thermal expansion in a metal-organic framework.

    Science.gov (United States)

    van Heerden, Dewald P; Esterhuysen, Catharine; Barbour, Leonard J

    2016-03-14

    The previously reported anisotropic thermal expansion of a three-dimensional metal-organic framework (MOF) is examined by means of theoretical calculations. Inspection of the 100, 190, 280 and 370 K single crystal X-ray diffraction (SCD) structures indicated a concerted change in the coordination sphere of the zinc centre leading to elongation of the coordination helix in the crystallographic c direction (the Zn-O(H)-Zn angle expands), while the largely unaltered ligands (the ZnLZn distance remains constant) are pulled closer together in the ab plane. This study develops and evaluates a mechanistic model at the DFT level of theory that reproduces the convergent expansion of the coordination helix of the material. The linear increase in energy calculated for extension of a model consisting of six zinc centres and truncated ligands compares favourably with results obtained from a periodic DFT evaluation of the SCD structures. It was also found that the anisotropic thermal expansion trend could be reproduced qualitatively by Molecular Dynamics (MD) simulations in the NPT ensemble.

  18. Kinetic and steric differences in adsorption in two porous metal-organic frameworks

    Science.gov (United States)

    Lask, Kathleen; Krungleviciute, Vaiva; Bulut, Murat; Migone, Aldo; Lee, J.-Y.; Li, Jing

    2008-03-01

    Kinetic and steric differences are two of the three fundamental mechanisms underlying the use of adsorption in applications to gas mixture separations. We present experimental results on kinetics and equilibrium adsorption measurements of tetrafluoromethane and argon on two metal-organic framework (MOF) materials: RPM1-Co or [Co3(bpdc)3bpy].4DMF.H2O] (bpdc = biphenyldicarboxylate, bpy = 4,4'-bipyridine, DMF = N,N- dimethylformamide) and Cu-BTC or Cu3(BTC)2(H2O)3 (BTC = benzene-1,3,5-tricarboxylate). The adsorbates display significant differences in their kinetics on RPM1-Co (i.e., there are sizable differences in the time required for each gas to reach equilibrium after it is allowed access to the substrate). Our equilibrium measurements show that CF4 is sterically precluded from adsorbing in the small tetrahedral-shaped side pockets present in Cu-BTC. We will compare our experimental results with predictions for how adsorption kinetics depends on the size of the adsorbate and on those of the pores present in the substrate.

  19. Anthracene-Based Lanthanide Metal-Organic Frameworks: Synthesis, Structure, Photoluminescence, and Radioluminescence Properties

    Directory of Open Access Journals (Sweden)

    Stephan R. Mathis

    2018-01-01

    Full Text Available Four anthracene-based lanthanide metal-organic framework structures (MOFs were synthesized from the combination of the lanthanide ions, Eu3+, Tb3+, Er3+, and Tm3+, with 9,10-anthracenedicarboxylic acid (H2ADC in dimethylformamide (DMF under hydrothermal conditions. The 3-D networks crystalize in the triclinic system with P-1 space group with the following compositions: (i {{[Ln2(ADC3(DMF4·DMF]}n, Ln = Eu (1 and Tb (2} and (ii {{[Ln2(ADC3(DMF2(OH22·2DMF·H2O]}n, Ln = Er (3 and Tm (4}. The metal centers exist in various coordination environments; nine coordinate in (i, while seven and eight coordinate in (ii. The deprotonated ligand, ADC, assumes multiple coordination modes, with its carboxylate functional groups severely twisted away from the plane of the anthracene moiety. The structures show ligand-based photoluminescence, which appears to be significantly quenched when compared with that of the parent H2ADC solid powder. Structure 2 is the least quenched and showed an average photoluminescence lifetime from bi-exponential decay of 0.3 ns. On exposure to ionizing radiation, the structures show radioluminescence spectral features that are consistent with the isolation of the ligand units in its 3-D network. The spectral features vary among the 3-D networks and appear to suggest that the latter undergo significant changes in their molecular and/or electronic structure in the presence of the ionizing radiation.

  20. Luminescent Lanthanide MOFs: A Unique Platform for Chemical Sensing.

    Science.gov (United States)

    Zhao, Shu-Na; Wang, Guangbo; Poelman, Dirk; Voort, Pascal Van Der

    2018-04-07

    In recent years, lanthanide metal-organic frameworks (LnMOFs) have developed to be an interesting subclass of MOFs. The combination of the characteristic luminescent properties of Ln ions with the intriguing topological structures of MOFs opens up promising possibilities for the design of LnMOF-based chemical sensors. In this review, we present the most recent developments of LnMOFs as chemical sensors by briefly introducing the general luminescence features of LnMOFs, followed by a comprehensive investigation of the applications of LnMOF sensors for cations, anions, small molecules, nitroaromatic explosives, gases, vapors, pH, and temperature, as well as biomolecules.

  1. Open metal-organic framework containing cuprate chains.

    Science.gov (United States)

    Tran, Dat T; Fan, Xiaojuan; Brennan, Daniel P; Zavalij, Peter Y; Oliver, Scott R J

    2005-09-05

    A three-dimensional Cu(II) metal-organic framework, copper hydroxide p-pyridinecarboxylate hydrate, [Cu(OH)(C5H4NCO2).H2O], was synthesized by hydrothermally reacting copper nitrate with p-pyridinecarboxylic acid. The crystals were suitable for single-crystal X-ray diffraction analysis, which showed that the Cu(II) centers adopt a slightly distorted square pyramidal geometry. They coordinate to both the pyridyl and carboxylate functionalities of the pyridinecarboxylate bridging ligands. Infinite copper oxide chains run through the structure and are connected by p-pyridinecarboxylate (p-PyC) ligands. Crystal data: monoclinic, space group P2(1)/n, a = 3.5521(2) A, b = 15.8665(11) A, c = 12.9977(9) A, beta = 95.285(2) degrees , and Z = 4. Thermogravimetric analysis (TGA) revealed that the guest H2O molecules in the channels may be removed, and the material is stable to ca. 245 degrees C. Magnetic measurements indicated the material has one-dimensional (1D) antiferromagnetic ordering within the Cu2+ chains with a Néel temperature of ca. 51 K. Data fitting to the Bonner-Fisher model yielded a coupling constant, J, of -7.3 cm(-1) and g factor of 2.15. The Curie tail below 20 K is due to a small amount of paramagnetic impurities, calculated to be approximately 0.2% in concentration. Further characterization of crystallinity and morphology are discussed, including powder X-ray diffraction (PXRD), elemental analysis, and optical microscopy.

  2. Metal-organic framework templated electrodeposition of functional gold nanostructures

    International Nuclear Information System (INIS)

    Worrall, Stephen D.; Bissett, Mark A.; Hill, Patrick I.; Rooney, Aidan P.; Haigh, Sarah J.; Attfield, Martin P.; Dryfe, Robert A.W.

    2016-01-01

    Highlights: • Electrodeposition of anisotropic Au nanostructures templated by HKUST-1. • Au nanostructures replicate ∼1.4 nm pore spaces of HKUST-1. • Encapsulated Au nanostructures active as SERS substrate for 4-fluorothiophenol. - Abstract: Utilizing a pair of quick, scalable electrochemical processes, the permanently porous MOF HKUST-1 was electrochemically grown on a copper electrode and this HKUST-1-coated electrode was used to template electrodeposition of a gold nanostructure within the pore network of the MOF. Transmission electron microscopy demonstrates that a proportion of the gold nanostructures exhibit structural features replicating the pore space of this ∼1.4 nm maximum pore diameter MOF, as well as regions that are larger in size. Scanning electron microscopy shows that the electrodeposited gold nanostructure, produced under certain conditions of synthesis and template removal, is sufficiently inter-grown and mechanically robust to retain the octahedral morphology of the HKUST-1 template crystals. The functionality of the gold nanostructure within the crystalline HKUST-1 was demonstrated through the surface enhanced Raman spectroscopic (SERS) detection of 4-fluorothiophenol at concentrations as low as 1 μM. The reported process is confirmed as a viable electrodeposition method for obtaining functional, accessible metal nanostructures encapsulated within MOF crystals.

  3. A dysprosium-based metal-organic framework: Synthesis ...

    Indian Academy of Sciences (India)

    -BSA adduct was assumed to be the .... A Dy-based MOF and biological activity ... Crystal data and details of refinement for com- pound 1. Empirical Formula. C21H32Ca1.50DyN3O22.50. Formula Weight. 909.12. Crystal System. Monoclinic.

  4. Supramolecular Isomers of Metal-Organic Frameworks Derived from a Partially Flexible Ligand with Distinct Binding Motifs

    KAUST Repository

    Abdul Halim, Racha Ghassan

    2016-01-04

    Three novel metal-organic frameworks (MOFs) were isolated upon reacting a heterofunctional ligand 4 (pyrimidin-5 yl)benzoic acid (4,5-pmbc) with mixed valence Cu(I,II) under solvothermal conditions. X-ray crystal structural analysis reveals that the first compound is a layered structure composed of one type of inorganic building block, dinuclear paddlewheel [Cu2(O2C–)4], which are linked through 4,5-pmbc ligands. The two other supramolecular isomers are composed of the same Cu(II) dinuclear paddlewheel and a dinuclear Cu2I2 cluster, which are linked via the 4,5-pmbc linkers to yield two different 3-periodic frameworks with underlying topologies related to lvt and nbo. The observed structural diversity in these structures is due to the distinct coordination modes of the two coordinating moieties (the carboxylate group on the phenyl ring and the N-donor atoms from the pyrimidine moiety).

  5. Highly porous ionic rht metal-organic framework for H2 and CO2 storage and separation: A molecular simulation study

    KAUST Repository

    Babarao, Ravichandar

    2010-07-06

    The storage and separation of H2 and CO2 are investigated in a highly porous ionic rht metal-organic framework (rht-MOF) using molecular simulation. The rht-MOF possesses a cationic framework and charge-balancing extraframework NO3 - ions. Three types of unique open cages exist in the framework: rhombicuboctahedral, tetrahedral, and cuboctahedral cages. The NO3 - ions exhibit small mobility and are located at the windows connecting the tetrahedral and cuboctahedral cages. At low pressures, H2 adsorption occurs near the NO 3 - ions that act as preferential sites. With increasing pressure, H2 molecules occupy the tetrahedral and cuboctahedral cages and the intersection regions. The predicted isotherm of H2 at 77 K agrees well with the experimental data. The H2 capacity is estimated to be 2.4 wt % at 1 bar and 6.2 wt % at 50 bar, among the highest in reported MOFs. In a four-component mixture (15:75:5:5 CO2/H 2/CO/CH4) representing a typical effluent gas of H 2 production, the selectivity of CO2/H2 in rht-MOF decreases slightly with increasing pressure, then increases because of cooperative interactions, and finally decreases as a consequence of entropy effect. By comparing three ionic MOFs (rht-MOF, soc-MOF, and rho-ZMOF), we find that the selectivity increases with increasing charge density or decreasing free volume. In the presence of a trace amount of H2O, the interactions between CO2 and NO3 - ions are significantly shielded by H2O; consequently, the selectivity of CO 2/H2 decreases substantially. © 2010 American Chemical Society.

  6. Graphene-wrapped sulfur/metal organic framework-derived microporous carbon composite for lithium sulfur batteries

    Directory of Open Access Journals (Sweden)

    Renjie Chen

    2014-12-01

    Full Text Available A three-dimensional hierarchical sandwich-type graphene sheet-sulfur/carbon (GS-S/CZIF8-D composite for use in a cathode for a lithium sulfur (Li-S battery has been prepared by an ultrasonic method. The microporous carbon host was prepared by a one-step pyrolysis of Zeolitic Imidazolate Framework-8 (ZIF-8, a typical zinc-containing metal organic framework (MOF, which offers a tunable porous structure into which electro-active sulfur can be diffused. The thin graphene sheet, wrapped around the sulfur/zeolitic imidazolate framework-8 derived carbon (S/CZIF8-D composite, has excellent electrical conductivity and mechanical flexibility, thus facilitating rapid electron transport and accommodating the changes in volume of the sulfur electrode. Compared with the S/CZIF8-D sample, Li-S batteries with the GS-S/CZIF8-D composite cathode showed enhanced capacity, improved electrochemical stability, and relatively high columbic efficiency by taking advantage of the synergistic effects of the microporous carbon from ZIF-8 and a highly interconnected graphene network. Our results demonstrate that a porous MOF-derived scaffold with a wrapped graphene conductive network structure is a potentially efficient design for a battery electrode that can meet the challenge arising from low conductivity and volume change.

  7. A flexible metal-organic framework with a high density of sulfonic acid sites for proton conduction

    Science.gov (United States)

    Yang, Fan; Xu, Gang; Dou, Yibo; Wang, Bin; Zhang, Heng; Wu, Hui; Zhou, Wei; Li, Jian-Rong; Chen, Banglin

    2017-11-01

    The design of stable electrolyte materials with high proton conductivity for use in proton exchange membrane fuel cells remains a challenge. Most of the materials explored have good conductivity at high relative humidity (RH), but significantly decreased conductivity at reduced RH. Here we report a chemically stable and structurally flexible metal-organic framework (MOF), BUT-8(Cr)A, possessing a three-dimensional framework structure with one-dimensional channels, in which high-density sulfonic acid (-SO3H) sites arrange on channel surfaces for proton conduction. We propose that its flexible nature, together with its -SO3H sites, could allow BUT-8(Cr)A to self-adapt its framework under different humid environments to ensure smooth proton conduction pathways mediated by water molecules. Relative to other MOFs, BUT-8(Cr)A not only has a high proton conductivity of 1.27 × 10-1 S cm-1 at 100% RH and 80 °C but also maintains moderately high proton conductivity at a wide range of RH and temperature.

  8. Magnetic porous carbon nanocomposites derived from metal-organic frameworks as a sensing platform for DNA fluorescent detection

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Hongliang, E-mail: hltan@jxnu.edu.cn; Tang, Gonge; Wang, Zhixiong; Li, Qian; Gao, Jie; Wu, Shimeng

    2016-10-12

    Metal-organic frameworks (MOFs) have emerged as very fascinating functional materials due to their tunable nature and diverse applications. In this work, we prepared a magnetic porous carbon (MPC) nanocomposite by employing iron-containing MOFs (MIL-88A) as precursors through a one-pot thermolysis method. It was found that the MPC can absorb selectively single-stranded DNA (ssDNA) probe to form MPC/ssDNA complex and subsequently quench the labelled fluorescent dye of the ssDNA probe, which is resulted from the synergetic effect of magnetic nanoparticles and carbon matrix. Upon the addition of complementary target DNA, however, the absorbed ssDNA probe could be released from MPC surface by forming double-stranded DNA with target DNA, and accompanied by the recovery of the fluorescence of ssDNA probe. Based on these findings, a sensing platform with low background signal for DNA fluorescent detection was developed. The proposed sensing platform exhibits high sensitivity with detection limit of 1 nM and excellent selectivity to specific target DNA, even single-base mismatched nucleotide can be distinguished. We envision that the presented study would provide a new perspective on the potential applications of MOF-derived nanocomposites in biomedical fields. - Highlights: • A MOF-derived magnetic porous carbon-based DNA fluorescent sensor was developed. • The MPC can absorb selectively single-stranded DNA probe and subsequently quench its labelled fluorescent dye. • The DNA fluorescent sensor showed excellent selectivity and high sensitivity.

  9. Hydrolytically Stable Luminescent Cationic Metal Organic Framework for Highly Sensitive and Selective Sensing of Chromate Anions in Natural Water Systems.

    Science.gov (United States)

    Liu, Wei; Wang, Yanlong; Bai, Zhuanling; Li, Yuxiang; Wang, Yaxing; Chen, Lanhua; Xu, Lin; Diwu, Juan; Chai, Zhifang; Wang, Shuao

    2017-05-17

    Effective detection of chromate anions in aqueous solution is highly desirable because of their high solubility, environmental mobility, carcinogenicity, and bioaccumulation effect. A new strategy for precise detection of chromate anions in the presence of a large excess of other anions, such as Cl - , NO 3 - , and HCO 3 - , in drinking water and natural water systems remains a challenge. Herein, a hydrolytically stable cationic luminescent europium(III)-based metal organic framework (MOF), 1, was successfully synthesized and investigated as a luminescent sensor that exhibits instant and selective luminescence quenching properties toward chromate ions in aqueous solutions. Moreover, 1 can be introduced into high-ionic-strength water system (e.g., seawater) for chromate detection as a consequence of the excellent sensing selectivity. The real environmental application of 1 as a chromate probe is studied in deionized water, lake water, and seawater. The detection limits in these aqueous media are calculated to be 0.56, 2.88, and 1.75 ppb, respectively. All of these values are far below the maximum contamination standard of Cr(VI) in drinking water of 100 ppb, defined by the U.S. Environmental Protection Agency. This excellent chromate sensing capability originates from the fast enrichment of chromate ions in solids of 1 from solutions, followed by efficient energy transfer from the MOF skeleton to the chromate anion, as demonstrated by solution absorption spectroscopy, X-ray diffraction, and chromate uptake kinetics and isotherm investigations. To the best of our knowledge, 1 possesses the lowest chromate detection limit among all reported MOFs up to date and is the only MOF material reported for chromate sensing application under environmentally relevant conditions with high ionic strengths.

  10. BSA-AuNPs@Tb-AMP metal-organic frameworks for ratiometric fluorescence detection of DPA and Hg2.

    Science.gov (United States)

    Cai, Keying; Zeng, Mulan; Liu, Fenfen; Liu, Nan; Huang, Zhenzhong; Song, Yonghai; Wang, Li

    2017-11-01

    An easy and effective strategy for synthesizing a ratiometric fluorescent nanosensor has been demonstrated in this work. Novel fluorescent BSA-AuNPs@Tb-AMP (BSA, bovine serum albumin; AMP, adenosine 5'-monophosphate; AuNPs, Au nanoparticles) metal-organic framework (MOF) nanostructures were synthesized by encapsulating BSA-AuNPs into Tb-AMP MOFs for the detection of 2,6-pyridinedicarboxylic acid (DPA) and Hg 2+ . DPA could strongly co-ordinate with Tb 3+ to replace water molecules from the Tb 3+ center and accordingly enhanced the fluorescence of Tb-AMP MOFs. The fluorescence of BSA-AuNPs at 405 nm remained constant. While the fluorescence of BSA-AuNPs at 635 nm was quenched after Hg 2+ was added, the fluorescence of Tb-AMP MOFs remained constant. Accordingly, a ratiometric fluorescence nanosensor was constructed for detection of DPA and Hg 2+ . The ratiometric nanosensor exhibited good selectivity to DPA over other substances. The F 545 /F 405 linearly increased with increase of DPA concentration in the range of 50 nM to 10 μM with a detection limit as low as 17.4 nM. F 635 /F 405 increased linearly with increase of Hg 2+ concentration ranging from 50 nM to 1 μM with a detection limit as low as 20.9 nM. Additionally, the nanosensor could be successfully applied for the determination of DPA and Hg 2+ in running water. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Construction of three lanthanide metal-organic frameworks: Synthesis, structure, magnetic properties and highly selective sensing of metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiu-Mei, E-mail: zhangxiumeilb@126.com; Li, Peng; Gao, Wei; Liu, Feng; Liu, Jie-Ping

    2016-12-15

    Three lanthanide metal-organic frameworks (Ln-MOFs), [Ln(TZI)(H{sub 2}O){sub 4}]·3H{sub 2}O (Ln=Gd (1) and Tb (2) and Dy (3), H{sub 3}TZI=5-(1H-tetrazol-5-yl)isophthalic acid), have been synthesized under hydrothermal conditions. Single crystal X-ray diffraction reveals that 1–3 are isostructural and display a 1D double chain based on dinuclear motifs with (μ-COO){sub 2} double bridges. Magnetic studies indicate antiferromagnetic interactions in 1, ferromagnetic interactions in 2 and 3. Furthermore, compound 3 displays a slow relaxation behavior. Compound 2 exhibits intense characteristic green emission of Tb(III) ions in the solid state, which can be observed by the naked eye under UV light. Interestingly, 2 can selectively sense Pb{sup 2+} and Fe{sup 3+} ions through luminescence enhancement and quenching, respectively. The luminescence quenching mechanisms have been investigated in detail. The study on luminescence Ln-MOFs as a probe for sensing Pb{sup 2+} and Fe{sup 3+} ions is exceedingly rare example. - Graphical abstract: Three Ln-MOFs were successfully synthesized using a 5-(1H-tetrazol-5-yl)isophthalic acid ligand. They displays different magnetic behavior. Especially, the Dy(III) compound slow relaxation behavior. Interestingly, the Tb(III) compound can selectively sense Pb{sup 2+} and Fe{sup 3+} ions through luminescence enhancement and quenching, respectively. - Highlights: • Three Ln-MOFs with tetrazolate dicarboxylate ligand. • Dy(III) compound displays slow relaxation behavior. • The Tb(III) compound shows highly selective luminescence sensing of the Fe{sup 3+} and Pb{sup 2+} ions.

  12. Methods for associating or dissociating guest materials with a metal organic framework, systems for associating or dissociating guest materials within a series of metal organic frameworks, thermal energy transfer assemblies, and methods for transferring thermal energy

    Science.gov (United States)

    McGrail, B. Peter; Brown, Daryl R.; Thallapally, Praveen K.

    2016-08-02

    Methods for releasing associated guest materials from a metal organic framework are provided. Methods for associating guest materials with a metal organic framework are also provided. Methods are provided for selectively associating or dissociating guest materials with a metal organic framework. Systems for associating or dissociating guest materials within a series of metal organic frameworks are provided. Thermal energy transfer assemblies are provided. Methods for transferring thermal energy are also provided.

  13. A multiferroic material [NH2-CH+-NH2]Co(HCOO3 of metal-organic frameworks with weak ferromagnetism and dielectric relaxation

    Directory of Open Access Journals (Sweden)

    Jiangqi Luo

    2017-10-01

    Full Text Available In order to seek for the single-phase multiferroic metal-organic frameworks (MOFs materials, we prepared a multiferroic material [NH2-CH+-NH2]Co(HCOO3 (FMDCo by solvothermal method. We found that it had weak ferromagnetism below 12.5 K with the coercive fields (Hc of 560 Oe, remnant magnetization (Mr of 7.67 emu/g and saturation magnetization (Ms of 10.3 emu/g and exhibited obvious dielectric relaxation. The octahedral metal ions (Co2+ were linked by formate (HCOO- ligands. The AmineH+ cation (NH2-CH+-NH2 were located within the cube-like cavities of the framework and formed extensive hydrogen bonds with the framework. This improved the phase transition temperature and thermal stability. This finding helps to understand the nature of magnetic and electric ordering in the MOFs.

  14. Luminescent lanthanide metal-organic frameworks for chemical sensing and toxic anion detection.

    Science.gov (United States)

    Wu, Rui-Zhi; Yang, Xing; Zhang, Liang-Wei; Zhou, Pan-Pan

    2017-08-01

    Prototype lanthanide metal-organic frameworks (LnMOFs), Ln(BTC) (Ln = Eu and Tb; BTC = benzene-1,3,5-tricarboxylate), have been considered as luminescent sensors for detecting toxic anions, while their neutral pore structures have limited the entrance and encapsulation of anions to produce highly anion-responsive photoluminescence (PL). To facilitate anions to enter the pore space of Ln(BTC), a one-pot synthesis method was proposed in which BTC was partially replaced with its structural analogue L·BF 4 (H 3 L·BF 4 = 2,4,6-tricarboxy-1-methylpyridinium tetrafluoroborate) which consists of an anion affinity site of cationic methylpyridinium. Compared to the original Ln(BTC), the co-doped cationic framework Eu 0.05 Tb 0.95 -BTC 0.9 L 0.1 is highly sensitive for detecting different toxic anions by tuning the energy absorption of organic chromophores, the energy transfer efficiency to Ln 3+ ions and the energy allocation between different Ln 3+ ions in the PL spectra. We demonstrated that the Eu 0.05 Tb 0.95 -BTC 0.9 L 0.1 PL sensor has the capability of decoding various toxic anions with a clearly differentiable and unique emission intensity ratio of 5 D 4 → 7 F 5 (Tb 3+ , 545 nm) to 5 D 0 → 7 F 2 (Eu 3+ , 618 nm) transitions (I Tb /I Eu ). Compared to Ln(BTC), the co-doped Eu 0.05 Tb 0.95 -BTC 0.9 L 0.1 presents self-calibrating, high distinguishable and stable PL signals for detecting toxic anions.

  15. Two Water Stable Copper Metal-Organic Frameworks with Performance in the Electrocatalytic Activity for Water Oxidation

    Directory of Open Access Journals (Sweden)

    Liu Xiuping

    2018-01-01

    Full Text Available Two novel water stable metal-organic frameworks, [Cu(L·(4,4′-bipy·(ClO4]n (1, [Cu(L·(phen·(ClO4·(H2O]2 (2, have been constructed by HL=[5-Mercapto-1-methyl] tetrazole acetic acid and Cu (II salt in the presence of assistant N-containing ligands. MOF 1 and MOF 2 with open CuII sites, resulting the framework 1 and 2 show electrocatalytic activity for water oxidation in alkaline solution. The electrochemical properties of complex for oxygen evolution reaction (OER were evaluated by linear sweep voltammetry (LSV and the Tafel slopes. Complex 1 has a higher LSV activity with a lower over potential of 1.54 V and a much higher increase in current density. Meanwhile, the Tafel slope of complex 1 (122.0 mV dec-1 is much lower than complex 2 (243.5 mV dec-1. This phenomenon makes complex 1 a promising porous material for electrocatalytic activity.

  16. Advanced Photoemission Spectroscopy Investigations Correlated with DFT Calculations on the Self-Assembly of 2D Metal Organic Frameworks Nano Thin Films.

    Science.gov (United States)

    Elzein, Radwan; Chang, Chun-Min; Ponomareva, Inna; Gao, Wen-Yang; Ma, Shengqian; Schlaf, Rudy

    2016-11-16

    Metal-organic frameworks (MOFs) deposited from solution have the potential to form 2-dimensional supramolecular thin films suitable for molecular electronic applications. However, the main challenges lie in achieving selective attachment to the substrate surface, and the integration of organic conductive ligands into the MOF structure to achieve conductivity. The presented results demonstrate that photoemission spectroscopy combined with preparation in a system-attached glovebox can be used to characterize the electronic structure of such systems. The presented results demonstrate that porphyrin-based 2D MOF structures can be produced and that they exhibit similar electronic structure to that of corresponding conventional porphyrin thin films. Porphyrin MOF multilayer thin films were grown on Au substrates prefunctionalized with 4-mercaptopyridine (MP) via incubation in a glovebox, which was connected to an ultrahigh vacuum system outfitted with photoelectron spectroscopy. The thin film growth process was carried out in several sequential steps. In between individual steps the surface was characterized by photoemission spectroscopy to determine the valence bands and evaluate the growth mode of the film. A comprehensive evaluation of X-ray photoemission spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and inverse photoemission spectroscopy (IPES) data was performed and correlated with density functional theory (DFT) calculations of the density of states (DOS) of the films involved to yield the molecular-level insights into the growth and the electronic properties of MOF-based 2D thin films.

  17. Effects of functionalization, catenation, and variation of the metal oxide and organic linking units on the low-pressure hydrogen adsorption properties of metal-organic frameworks.

    Science.gov (United States)

    Rowsell, Jesse L C; Yaghi, Omar M

    2006-02-01

    The dihydrogen adsorption isotherms of eight metal-organic frameworks (MOFs), measured at 77 K up to a pressure of 1 atm, have been examined for correlations with their structural features. All materials display approximately Type I isotherms with no hysteresis, and saturation was not reached for any of the materials under these conditions. Among the six isoreticular MOFs (IRMOFs) studied, the catenated materials exhibit the largest capacities on a molar basis, up to 9.8 H(2) per formula unit. The addition of functional groups (-Br, -NH(2), -C(2)H(4)-) to the phenylene links of IRMOF-1 (MOF-5), or their replacement with thieno[3,2-b]thiophene moieties in IRMOF-20, altered the adsorption behavior by a minor amount despite large variations in the pore volumes of the resulting materials. In contrast, replacement of the metal oxide units with those containing coordinatively unsaturated metal sites resulted in greater H(2) uptake. The enhanced affinities of these materials, MOF-74 and HKUST-1, were further demonstrated by calculation of the isosteric heats of adsorption, which were larger across much of the range of coverage examined, compared to those of representative IRMOFs. The results suggest that under low-loading conditions, the H(2) adsorption behavior of MOFs can be improved by imparting larger charge gradients on the metal oxide units and adjusting the link metrics to constrict the pore dimensions; however, a large pore volume is still a prerequisite feature.

  18. Effect of central metal ions of analogous metal-organic frameworks on adsorption of organoarsenic compounds from water: plausible mechanism of adsorption and water purification.

    Science.gov (United States)

    Jun, Jong Won; Tong, Minman; Jung, Beom K; Hasan, Zubair; Zhong, Chongli; Jhung, Sung Hwa

    2015-01-02

    The adsorptive removal of organoarsenic compounds such as p-arsanilic acid (ASA) and roxarsone (ROX) from water using metal-organic frameworks (MOFs) has been investigated for the first time. A MOF, iron benzenetricarboxylate (also called MIL-100-Fe) exhibits a much higher adsorption capacity for ASA and ROX than activated carbon, zeolite (HY), goethite, and other MOFs. The adsorption of ASA and ROX over MIL-100-Fe is also much more rapid than that over activated carbon. Moreover, the used MIL-100-Fe can be recycled by simply washing with acidic ethanol. Therefore, it is determined that a MOF such as MIL-100-Fe can be used to remove organoarsenic compounds from contaminated water because of its high adsorption capacity, rapid adsorption, and ready regeneration. Moreover, only one of three analogous MIL-100 species (MIL-100-Fe, rather than MIL-100-Al or MIL-100-Cr) can effectively remove the organoarsenic compounds. This selective and high adsorption over MIL-100-Fe, different from other analogous MIL-100 species, can be explained (through calculations) by the facile desorption of water from MIL-100-Fe as well as the large (absolute value) replacement energy (difference between the adsorption energies of the organoarsenic compounds and water) exhibited by MIL-100-Fe. A plausible adsorption/desorption mechanism is proposed based on the surface charge of the MOFs, FTIR results, calculations, and the reactivation results with respect to the solvents used in the experiments. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Arene guest selectivity and pore flexibility in a metal-organic framework with semi-fluorinated channel walls

    Science.gov (United States)

    Smith, Rebecca; Vitórica-Yrezábal, Iñigo J.; Hill, Adrian; Brammer, Lee

    2017-01-01

    A metal-organic framework (MOF) with one-dimensional channels of approximately hexagonal cross-section [Ag2(O2CCF2CF2CO2)(TMP)] 1 (TMP =2,3,5,6-tetramethylpyrazine) has been synthesized with MeOH filling the channels in its as-synthesized form as [Ag2(O2CCF2CF2CO2)(TMP)]·n(MeOH) 1-MeOH (n = 1.625 by X-ray crystallography). The two types of ligand connect columns of Ag(I) centres in an alternating manner, both around the channels and along their length, leading to an alternating arrangement of hydrocarbon (C-H) and fluorocarbon (C-F) groups lining the channel walls, with the former groups projecting further into the channel than the latter. MeOH solvent in the channels can be exchanged for a variety of arene guests, ranging from xylenes to tetrafluorobenzene, as confirmed by gas chromatography, 1H nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis and 13C cross-polarization magic angle spinning NMR spectroscopy. Alkane and perfluoroalkane guests, however, do not enter the channels. Although exhibiting some stability under a nitrogen atmosphere, sufficient to enable crystal structure determination, the evacuated MOF 1 is unstable for periods of more than minutes under ambient conditions or upon heating, whereupon it undergoes an irreversible solid-state transformation to a non-porous polymorph 2, which comprises Ag2(O2CCF2CF2CO2) coordination layers that are pillared by TMP ligands. This transformation has been followed in situ by powder X-ray diffraction and shown to proceed via a crystalline intermediate. This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.

  20. High conductive, long-term durable, anhydrous proton conductive solid-state electrolyte based on a metal-organic framework impregnated with binary ionic liquids: Synthesis, characteristic and effect of anion

    Science.gov (United States)

    Chen, Hui; Han, Shu-Yan; Liu, Rui-Heng; Chen, Teng-Fei; Bi, Kai-Lun; Liang, Jian-Bo; Deng, Yu-Heng; Wan, Chong-Qing

    2018-02-01

    Incorporating ionic liquids (abbreviated as ILs) into porous metal-organic framework (MOF) to obtain ILs@MOF nanocomposites is documented as a feasible method to achieve new type of anhydrous proton conductor with high performance. We newly synthesized a series of ILs with different acid counter anions (R-SO3-) and their ILs@MOF hybrid materials, i.e. SA-EIMS@MIL-101, MSA-EIMS@MIL-101 and PTSA-EIMS@MIL-101 (SA = sulfate acid, MSA = methanesulfonate acid, PTSA = p-toluenesulfonate acid, EIMS = 1-(1-ethyl-3-imidazolium)propane-3-sulfonate). Such hybrid materials displayed as anhydrous proton conduction with long-term durability even heated at 150 °C open to air. σ value of SA-EIMS@MIL-101 is up to 1.89 × 10-3 S cm-1, being in the range of the most conductive MOF-based materials. MOF support exhibited favorable proton transport and long-term retention for ILs. Anion volumes of R-SO3- displayed significant effects on the proton conductivity of such hybrid ILs@MOF materials. The smaller the van der Waals volume of R-SO3- is, the higher the conductivity of ILs@MOF is. This work suggests that the combination of a variety of the incorporated ILs and a MOF framework would afford high proton transport and gives an idea to explore the safe, anhydrous, solid-state electrolyte for high temperature proton exchange membrane fuel cell.

  1. Synthesis, Crystal Structure, and Luminescent Properties of New Zinc(II and Cadmium(II Metal-Organic Frameworks Based on Flexible Bis(imidazol-1-ylalkane Ligands

    Directory of Open Access Journals (Sweden)

    Marina Barsukova

    2016-10-01

    Full Text Available New metal-organic frameworks (MOFs based on zinc and cadmium ions, terephthalic acid, and flexible ligands 1,5-bis(imidazol-1-ylpentane or 1,6-bis(imidazol-1-ylhexane were prepared and characterized by X-ray diffraction, thermorgavimetric analysis and IR spectroscopy. The imidazolyl ligands were prepared by a new robust procedure involving the reaction between imidazole and 1,5-dibromopentane or 1,6-dibromohexane in a superbasic medium (KOH in DMSO. MOFs based on 1,5-bis(imidazol-1-ylpentane had diamond topology (dia and are triply interpenetrated. Ligands with longer spacer 1,6-bis(imidazol-1-ylhexane, terephthalate ions and zinc(II ions formed five-fold interpenetrated metal-organic framework also with dia topology, while cadmium(II ions with the same ligands formed eight-connected uninodal net with a very rare self-penetrated topological type ilc and a point symbol 424.5.63. The influence of the chemical composition of MOFs on their photoluminescent properties is investigated and discussed in detail.

  2. CO2 Capture Using the SIFSIX-2-Cu-i Metal-Organic Framework: A Computational Approach

    KAUST Repository

    Skarmoutsos, Ioannis

    2017-10-24

    The adsorption of carbon dioxide and its separation from mixtures with methane using the recently synthetized SIFSIX-2-Cu-i metal-organic framework (Nature, 2014, 495, 80-84) has been systematically studied by employing a variety of molecular simulation techniques. Quantum density functional theory calculations have been combined with force-field based Monte Carlo and molecular dynamics simulations in order to provide a deeper insight on the molecular-scale processes controlling the thermodynamic and dynamic adsorption selectivity of carbon dioxide over methane, giving particular emphasis on the mechanisms underlying the diffusion of the confined molecules in this porous hybrid material. The diffusion process was revealed to be mainly controlled by both (i) the residence dynamics around some specific interaction sites of the fluorinated metal-organic framework and (ii) the dynamics related to the process where faster molecules overtake slower ones in the narrow one-dimensional channel of SIFSIX-2-Cu-i. We further unveil a 1-dimensional diffusion behavior of both carbon dioxide and methane confined in this small pore MOF where single file diffusion is not observed.

  3. Kinetics and mechanism of the heterogeneous catalyzed oxidative decolorization of Acid-Blue 92 using bimetallic metal-organic frameworks.

    Science.gov (United States)

    El-sharkawy, Rehab G; El-din, Ahmed S Badr; El-din H Etaiw, Safaa

    2011-09-01

    The kinetics study of the oxidative decolorization of Acid-Blue 92 has been investigated by hydrogen peroxide catalyzed with bimetallic metal-organic frameworks. The used metal-organic frameworks (MOF) are [Ph3SnCu(CN)2·L] where L=pyrazine (pyz) 1, methylpyrazine (mepyz) 2, 4,4'-bipyridine (bpy) 3, trans-1,2-bis(4-pyridyl)ethene (tbpe) 4 or 1,2-bis(4-pyridyl)ethane (bpe) 5. The reaction was followed by conventional UV-Vis spectrophotometer at λmax=571 nm. The reaction exhibited first-order kinetics with respect to [dye] and [H2O2]. The reactivity of the catalysts depends on the type of the medium and thereafter decreases in strong alkaline media. Addition of NaCl enhances the reaction rate. Also, the irradiation of the reaction with UV-light enhanced the rate of AB-92 mineralization by about 86.9%. The reaction was entropy-controlled as confirmed by the isokinetic relationship. A reaction mechanism was proposed with the formation of free radicals as an oxidant. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. A water-stable lanthanide metal-organic framework for fluorimetric detection of ferric ions and tryptophan.

    Science.gov (United States)

    Abdelhamid, Hani Nasser; Bermejo-Gómez, Antonio; Martín-Matute, Belén; Zou, Xiaodong

    2017-01-01

    The preparation of a highly water stable and porous lanthanide metal-organic framework (MOF) nanoparticles (denoted SUMOF-7II; SU refers to Stockholm University) is described. SUMOF-7II was synthesized starting from the tritopic linker of 2,4,6-tri-p-carboxyphenyl pyridine (H 3 L2) and La(III) as metal clusters. SUMOF-7II forms a stable dispersion and displays high fluorescence emission with small variation over the pH range of 6 to 12. Its fluorescence is selectively quenched by Fe(III) ions compared to other metal ions. The intensity of the fluorescene emission drops drops linearly in 16.6-167 μM Fe(III) concentration range, and Stern-Volmer plots are linear. The limit of detection (LOD) is 16.6 μM (at an S/ N  ratio of >3). This indicator probe can also be used for selective detection of tryptophan among several amino acids. Compared to the free linker H 3 L2, SUMOF-7II offers improved sensitivity and selectivity of the investigated species. Graphical abstractA water-stable porous lanthanide metal-organic framework SUMOF-7II (La) has shown to be an excellent probe for the detection of ferric ions among other metal ions, and tryptophan among other amino acids in aqueous solution. The new probe displays high and stable fluorescence signal in a wide pH range (6-12).

  5. Coordination polymer nanocapsules prepared using metal-organic framework templates for pH-responsive drug delivery

    Science.gov (United States)

    Tang, Lei; Shi, Jiafu; Wang, Xiaoli; Zhang, Shaohua; Wu, Hong; Sun, Hongfan; Jiang, Zhongyi

    2017-07-01

    A facile, efficient, and versatile approach is presented to synthesize pH-responsive nanocapsules (˜120 nm) by combining the advantages of metal-organic frameworks (MOFs) and metal-organic thin films. ZIF-8 nanoparticles are used as templates on which a thin film coating of iron(III)-catechol complexes is derived from the coordination between dopamine-modified alginate (AlgDA) and iron(III) ions. After the template removal, nanocapsules with a pH-responsive wall are obtained. Doxorubicin (Dox), a typical anticancer drug, is first immobilized in ZIF-8 frameworks through coprecipitation and then encapsulated in nanocapsules after the removal of ZIF-8. The structure of the iron(III)-catechol complex varies with pH value, thus conferring the Dox@Nanocapsules with tailored release behavior in vitro. Cytotoxicity tests illustrate the highly effective cytotoxicity of Dox@Nanocapsules towards cancer cells. This study provides a new method for preparing smart nanocapsules and offers more opportunities for the controlled delivery of drugs.

  6. Preparation and Characterization of a Hydrophobic Metal-Organic Framework Membrane Supported on Thin Porous Metal Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jian; Canfield, Nathan L.; Liu, Wei

    2016-02-29

    A hydrophobic metal-organic framework (MOF) UiO-66-CH3 is prepared and its solvothermal stability is investigated in comparison to UiO-66. It is confirmed that the MOF stability is enhanced by introduction of the two methyl groups, while the water adsorption is reduced. Given its hydrophobicity and stability, UiO-66-CH3 is proposed as an attractive membrane material for gas separation under moisture conditions. The UiO-66-CH3 membrane is prepared on a 50µm-thin porous Ni support sheet for the first time by use of a secondary growth method. It is found that uniform seed coating on the support is necessary to form a continuous membrane. In addition to growth time and temperature, presence of a modulator in the growth solution is found to be useful for controlling hydrothermal membrane growth on the seeded support. A dense, inter-grown membrane layer is formed by 24-h growth over a temperature range from 120 oC to 160 oC. The membrane surface comprises 500 nm octahedral crystals, which are supposed to grow out of the original 100 nm spherical seeding crystals. The separation characteristics of resulting membranes are tested with pure CO2, air, CO2/air mixture, and humid CO2/air mixture. CO2 permeance as high as 1.9E-06 mol/m2/s/Pa at 31oC is obtained. Unlike the hydrophilic zeolite membranes, CO2 permeation through this membrane is not blocked by the presence of water vapor in the feed gas. The results suggest that this MOF framework is a promising membrane material worth to be further investigated for separation of CO2 and other small molecules from humid gas mixtures.

  7. Mechanochromic MOF nanoplates: spatial molecular isolation of light-emitting guests in a sodalite framework structure.

    Science.gov (United States)

    Chaudhari, Abhijeet K; Tan, Jin-Chong

    2018-02-22

    Mechanochromic materials have a wide range of promising technological applications, such as photonics-based sensors and smart optoelectronics. The examples of mechanochromic metal-organic framework (MOF) materials, however, are still relatively uncommon in the literature. Herein, we present a previously undescribed Guest@MOF system, comprising "Perylene@ZIF-8" nanoplates, which will undergo a reversible 442 nm ⇌ 502 nm photoemission switching when subjected to a moderate level of mechanically-induced pressure at several tens of MPa. The nanoplates were constructed via high-concentration reaction (HCR) strategy at ambient conditions to yield a crystalline ZIF-8 framework hosting the luminous Perylene guests. The latter confined within the porous sodalite cages of ZIF-8. Remarkably, we show that in a solid-state condition, it is the spatial isolation and nano-partitioning of the luminescent guests that bestow the unique solution-like optical properties measured in the host-guest assembly. As such, we demonstrate that switchable red- or blue-shifts of the visible emission can be accomplished by mechanically modifying the nanoscale packing of the nanoplates (e.g. monoliths, pellets). Theoretical calculations suggest that the elasticity of the host's sodalite cage coupled with the intermolecular weak interactions of the confined guest are responsible for the unique mechanochromic luminescence behavior observed.

  8. Size Modulation of Zirconium-Based Metal Organic Frameworks for Highly Efficient Phosphate Remediation.

    Science.gov (United States)

    Gu, Yue; Xie, Donghua; Ma, Yue; Qin, Wenxiu; Zhang, Haimin; Wang, Guozhong; Zhang, Yunxia; Zhao, Huijun

    2017-09-20

    Eutrophication of water bodies caused by the excessive phosphate discharge has constituted a serious threat on a global scale. It is imperative to exploit new advanced materials featuring abundant binding sites and high affinity to achieve highly efficient and specific capture of phosphate from polluted waters. Herein, water stable Zr-based metal organic frameworks (MOFs, UiO-66) with rational structural design and size modulation have been successfully synthesized based on a simple solvothermal method for effective phosphate remediation. Impressively, the size of the resulting UiO-66 particles can be effectively adjusted by simply altering reaction time and the amount of acetic acid with the purpose of understanding the crucial effect of structural design on the phosphate capture performance. Representatively, UiO-66 particles with small size demonstrates 415 mg/g of phosphate uptake capacity, outperforming most of the previously reported phosphate adsorbents. Meanwhile, the developed absorbents can rapidly reduce highly concentrated phosphate to below the permitted level in drinking water within a few minutes. More significantly, the current absorbents display remarkable phosphate sorption selectivity against the common interfering ions, which can be attributed to strong affinity between Zr-OH groups in UiO-66 and phosphate species. Furthermore, the spent UiO-66 particles can be readily regenerated and reused for multiple sorption-desorption cycles without obvious decrease in removal performance, rendering them promising sustainable materials. Hence, the developed UiO-66 adsorbents hold significant prospects for phosphate sequestration to mitigate the increasingly eutrophic problems.

  9. Porous ZnCo 2 O 4 nanoparticles derived from a new mixed-metal organic framework for supercapacitors

    KAUST Repository

    Chen, Siru

    2015-01-01

    Cobalt-based oxides have been shown to be promising materials for application in high-energy-density Li-ion batteries and supercapacitors. In this paper, we report a new and simple strategy for the synthesis of a mixed-metal spinel phase (ZnCo2O4) from a zinc and cobalt mixed-metal organic framework (JUC-155). It is important to rationally design a MOF with a precise ratio (Co/Zn) and a synthetic process that is simple and time saving. After solid-state annealing of the mixed-metal MOF precursor at 400 °C for two hours, a pure ZnCo2O4 phase with a high surface area (55 cm2 g−1) was obtained. When used as electrode materials for supercapacitors, an exceptionally high specific capacitance of 451 F g−1 was obtained at the scan rate of 5 mV s−1. The capacitance loss after 1500 cycles was only 2.1% at a current density of 2 A g−1, indicating that this phase has an excellent cycling stability. These remarkable electrochemical performances suggest that this phase is potentially promising for application as an efficient electrode in electrochemical capacitors.

  10. Spatial, Hysteretic, and Adaptive Host-Guest Chemistry in a Metal-Organic Framework with Open Watson-Crick Sites.

    Science.gov (United States)

    Cai, Hong; Li, Mian; Lin, Xiao-Rong; Chen, Wei; Chen, Guang-Hui; Huang, Xiao-Chun; Li, Dan

    2015-09-01

    Biological and artificial molecules and assemblies capable of supramolecular recognition, especially those with nucleobase pairing, usually rely on autonomous or collective binding to function. Advanced site-specific recognition takes advantage of cooperative spatial effects, as in local folding in protein-DNA binding. Herein, we report a new nucleobase-tagged metal-organic framework (MOF), namely ZnBTCA (BTC=benzene-1,3,5-tricarboxyl, A=adenine), in which the exposed Watson-Crick faces of adenine residues are immobilized periodically on the interior crystalline surface. Systematic control experiments demonstrated the cooperation of the open Watson-Crick sites and spatial effects within the nanopores, and thermodynamic and kinetic studies revealed a hysteretic host-guest interaction attributed to mild chemisorption. We further exploited this behavior for adenine-thymine binding within the constrained pores, and a globally adaptive response of the MOF host was observed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Electrochemiluminescent immunosensing of prostate-specific antigen based on silver nanoparticles-doped Pb (II) metal-organic framework.

    Science.gov (United States)

    Ma, Hongmin; Li, Xiaojian; Yan, Tao; Li, Yan; Zhang, Yong; Wu, Dan; Wei, Qin; Du, Bin

    2016-05-15

    In this work, silver nanoparticles-doped Pb (II) metal-organic framework (Ag-MOF) was prepared and exploited as a luminescence probe for the development of label-free electrochemiluminescence (ECL) immunosensing scheme for prostate-specific antigen (PSA). The β-cyclodextrin based MOF, Pb-β-cyclodextrin (Pb(II)-β-CD) shows excellent ECL behavior and unexpected reducing capacity towards silver ions. Silver nanoparticles could massively form on the surface of Pb(II)-β-CD (Ag@Pb(II)-β-CD) without use any additional reducing agent, while the ECL behavior of Pb(II)-β-CD still was well retained. The Ag@Pb(II)-β-CD was used as a substrate material to modify glass carbon electrodes and formed a sensing platform for the fabricating ECL immunosensor. The presence of silver nanoparticles enables the facile immobilization of capturing antibody of PSA. The specific binding of PSA onto the electrode surface induces the decrease of ECL signals. A linear range of 0.001-50 ng mL(-1) with a detection limit of 0.34 pg mL(-1) (S/N=3) was obtained after the optimization of experimental conditions. This simply fabricated immunosensor exhibits good stability, accuracy and acceptable reproducibility, which suggesting its potential applications in clinical diagnostics. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Nanostructured Electrode Materials Derived from Metal-Organic Framework Xerogels for High-Energy-Density Asymmetric Supercapacitor.

    Science.gov (United States)

    Mahmood, Asif; Zou, Ruqiang; Wang, Qingfei; Xia, Wei; Tabassum, Hassina; Qiu, Bin; Zhao, Ruo

    2016-01-27

    This work successfully demonstrates metal-organic framework (MOF) derived strategy to prepare nanoporous carbon (NPC) with or without Fe3O4/Fe nanoparticles by the optimization of calcination temperature as highly active electrode materials for asymmetric supercapacitors (ASC). The nanostructured Fe3O4/Fe/C hybrid shows high specific capacitance of 600 F/g at a current density of 1 A/g and excellent capacitance retention up to 500 F/g at 8 A/g. Furthermore, hierarchically NPC with high surface area also obtained from MOF gels displays excellent electrochemical performance of 272 F/g at 2 mV/s. Considering practical applications, aqueous ASC (aASC) was also assembled, which shows high energy density of 17.496 Wh/kg at the power density of 388.8 W/kg. The high energy density and excellent capacity retention of the developed materials show great promise for the practical utilization of these energy storage devices.

  13. Solvent-switchable continuous-breathing behaviour in a diamondoid metal-organic framework and its influence on CO2 versus CH4 selectivity

    Science.gov (United States)

    Carrington, Elliot J.; McAnally, Craig A.; Fletcher, Ashleigh J.; Thompson, Stephen P.; Warren, Mark; Brammer, Lee

    2017-09-01

    Understanding the behaviour of flexible metal-organic frameworks (MOFs)—porous crystalline materials that undergo a structural change upon exposure to an external stimulus—underpins their design as responsive materials for specific applications, such as gas separation, molecular sensing, catalysis and drug delivery. Reversible transformations of a MOF between open- and closed-pore forms—a behaviour known as 'breathing'—typically occur through well-defined crystallographic transitions. By contrast, continuous breathing is rare, and detailed characterization has remained very limited. Here we report a continuous-breathing mechanism that was studied by single-crystal diffraction in a MOF with a diamondoid network, (Me2NH2)[In(ABDC)2] (ABDC, 2-aminobenzene-1,4-dicarboxylate). Desolvation of the MOF in two different solvents leads to two polymorphic activated forms with very different pore openings, markedly different gas-adsorption capacities and different CO2 versus CH4 selectivities. Partial desolvation introduces a gating pressure associated with CO2 adsorption, which shows that the framework can also undergo a combination of stepped and continuous breathing.

  14. Photophysical Studies of Ru(II)tris(2,2`-bipyridine) Confined within a Zn(II)-Trimesic Acid Polyhedral Metal-Organic Framework

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Randy W; Wojtas, Lukasz [USF

    2012-10-25

    The ability to confine photoactive catalysts within metal-organic framework (MOF) materials affords the opportunity to expand the functional diversity of these materials into solar based applications. Here, the confinement of Ru(II)tris(2,2'-bipyridine) (RuBpy) by a MOF material derived from Zn(II) ions and trimesic acid (hereafter, USF2) is examined. Although the encapsulated RuBpy could not be crystallographically resolved within the MOF framework, the photophysical properties of the complex are characteristic of confinement including extended triplet metal-to-ligand (3MLCT) lifetime (τethanol = 614 ns and {τUSF2 = 1.2 μs at 25 °C) and a slight hypsochromic shift in the steady-state emission spectrum relative to RuBpy in ethanol. The extended lifetime is attributed to a deactivation of a nonradiative 3dd that is antibonding with respect to the Ru(II)-bipyridine due to a confined molecular environment. These results represent one of the first examples of RuBpy encapsulation and photophysical characterization within a polyhedral MOF material.

  15. Co2 and Co3 Mixed Cluster Secondary Building Unit Approach toward a Three-Dimensional Metal-Organic Framework with Permanent Porosity

    Directory of Open Access Journals (Sweden)

    Meng-Yao Chao

    2018-03-01

    Full Text Available Large and permanent porosity is the primary concern when designing metal-organic frameworks (MOFs for specific applications, such as catalysis and drug delivery. In this article, we report a MOF Co11(BTB6(NO34(DEF2(H2O14 (1, H3BTB = 1,3,5-tris(4-carboxyphenylbenzene; DEF = N,N-diethylformamide via a mixed cluster secondary building unit (SBU approach. MOF 1 is sustained by a rare combination of a linear trinuclear Co3 and two types of dinuclear Co2 SBUs in a 1:2:2 ratio. These SBUs are bridged by BTB ligands to yield a three-dimensional (3D non-interpenetrated MOF as a result of the less effective packing due to the geometrically contrasting SBUs. The guest-free framework of 1 has an estimated density of 0.469 g cm−3 and exhibits a potential solvent accessible void of 69.6% of the total cell volume. The activated sample of 1 exhibits an estimated Brunauer-Emmett-Teller (BET surface area of 155 m2 g−1 and is capable of CO2 uptake of 58.61 cm3 g−1 (2.63 mmol g−1, 11.6 wt % at standard temperature and pressure in a reversible manner at 195 K, showcasing its permanent porosity.

  16. Solvent-Controlled Assembly of ionic Metal-Organic Frameworks Based on Indium and Tetracarboxylate Ligand: Topology Variety and Gas Sorption Properties

    KAUST Repository

    Zheng, Bing

    2016-07-15

    Four Metal-Organic Frameworks (MOFs) based on Indium and tetracarboxylate ligand have been synthesized through regulation of the solvent conditions, the resulted compounds not only exhibited rich structural topologies (pts, soc and unique topologies), but also interesting charge reversal framework features. By regulating the solvent, different building units (indium monomer, trimer) have been generated in situ, and they are connected with the ligand to form ionic frameworks 1-4, respectively. Among the synthesized four ionic frameworks, compounds 3 and 4 could keep their crystallinity upon heating temperature up to 300oC after fully removal of solvent guest molecules, they also exhibit the charge reversal framework features (3 adopts an overall cationic framework, while 4 has an anionic framework). Both compounds 3 and 4 exhibit significant uptake capacity for CO2 and H2, besides that, compounds 3 and 4 also present excellent selective adsorption of CO2 over N2 and CH4.

  17. Mesoporous Fluorinated Metal-Organic Frameworks with Exceptional Adsorption of Fluorocarbons and CFCs

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Teng-Hao; Popov, Ilya; Kaveevivitchai, Watchareeya; Chuang, Yu-Chun; Chen, Yu-Sheng; Jacobson, Allan J.; Miljani,; #263; Ognjen, Š. [NSRRC; (UC); (Houston)

    2016-02-08

    Two mesoporous fluorinated metal–organic frameworks (MOFs) were synthesized from extensively fluorinated tritopic carboxylate- and tetrazolate-based ligands. The tetrazolate-based framework MOFF-5 has an accessible surface area of 2445 m2g-1, the highest among fluorinated MOFs. Crystals of MOFF-5 adsorb hydrocarbons, fluorocarbons, and chlorofluorocarbons (CFCs)—the latter two being ozone-depleting substances and potent greenhouse species—with weight capacities of up to 225%. The material exhibits an apparent preference for the adsorption of non-spherical molecules, binding unusually low amounts of both tetrafluoromethane and sulfur hexafluoride.

  18. A Biomimetic Approach to New Adsorptive Hydrogen Storage Metal-Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hongcai J [Texas A& M University

    2015-08-12

    In the past decades, there has been an escalation of interest in the study of MOFs due to their fascinating structures and intriguing application potentials. Their exceptionally high surface areas, uniform yet tunable pore sizes, and well-defined adsorbate-MOF interaction sites make them suitable for hydrogen storage. Various strategies to increase the hydrogen capacity of MOFs, such as constructing pore sizes comparable to hydrogen molecules, increasing surface area and pore volume, utilizing catenation, and introducing coordinatively unsaturated metal centers (UMCs) have been widely explored to increase the hydrogen uptake of the MOFs. MOFs with hydrogen uptake approaching the DOE gravimetric storage goal under reasonable pressure but cryo- temperature (typically 77 K) were achieved. However, the weak interaction between hydrogen molecules and MOFs has been the major hurdle limiting the hydrogen uptake of MOFs at ambient temperature. Along the road, we have realized both high surface area and strong interaction between framework and hydrogen are equally essential for porous materials to be practically applicable in Hydrogen storage. Increasing the isosteric heats of adsorption for hydrogen through the introduction of active centers into the framework could have great potential on rendering the framework with strong interaction toward hydrogen. Approaches on increasing the surface areas and improving hydrogen affinity by optimizing size and structure of the pores and the alignment of active centers around the pores in frameworks have been pursued, for example: (a) the introduction of coordinatively UMC (represents a metal center missing multiple ligands) with potential capability of multiple dihydrogen-binding (Kubas type, non-dissociative) per UMC, (b) the design and synthesis of proton-rich MOFs in which a + H3 binds dihydrogen just like a metal ion does, and (c) the preparation of MOFs and PPNs with well aligned internal electric fields. We believe the

  19. Isoreticular MOFs as Efficient Photocatalysts with Tunable Band Gap: An Operando FTIR Study of the Photoinduced Oxidation of Propylene

    NARCIS (Netherlands)

    Gascon, J.; Hernández-Alonso, M.D.; Almeida, A.R.; van Klink, G.P.M.; Kapteijn, F.; Mul, Guido

    2008-01-01

    Photo frame(work): The first spectroscopic evidence of metal-organic frameworks (MOFs) acting as photocatalysts has been obtained. Isoreticular MOFs act as efficient photocatalysts in the photooxidation of propylene. The band gap energy can be tuned by changing the organic linker. Among the MOFs

  20. Synthesis of nanostructured NiO/Co3O4 through thermal decomposition of a bimetallic (Ni/Co) metal-organic framework as catalyst for cyclooctene epoxidation

    Science.gov (United States)

    Abbasi, Alireza; Soleimani, Mohammad; Najafi, Mahnaz; Geranmayeh, Shokoofeh

    2017-04-01

    Hydrothermal approach has led to the formation of a three-dimensional metal-organic framework (MOF), [NiCo(μ2-tp)(μ4-tp)(4,4‧-bpy)2]n (1) (tp = terephthalic acid and 4,4‧-bpy = 4,4‧-bipyridine) which was characterized by means of single-crystal X-ray diffraction analysis, powder X-ray diffraction (PXRD), FT-IR spectroscopy, scanning electron microscopy (SEM) and inductive coupled plasma optical emission spectroscopy (ICP-OES). Thermal decomposition of the MOF afforded nanostructured mixed metal oxide, namely NiO/Co3O4. The XRD and SEM analysis confirm the formation of the mixed metal oxide. The nanostructured NiO/Co3O4 demonstrated good catalytic activity and selectivity in the epoxidation of cyclooctene in the presence of tert-butyl hydroperoxide (TBHP) as oxidant.

  1. Moisture-Stable Zn(II) Metal-Organic Framework as a Multifunctional Platform for Highly Efficient CO2 Capture and Nitro Pollutant Vapor Detection.

    Science.gov (United States)

    Chen, Di-Ming; Tian, Jia-Yue; Chen, Min; Liu, Chun-Sen; Du, Miao

    2016-07-20

    A moisture-stable three-dimensional (3D) metal-organic framework (MOF), {(Me2NH2)[Zn2(bpydb)2(ATZ)](DMA)(NMF)2}n (1, where bpydb = 4,4'-(4,4'-bipyridine-2,6-diyl)dibenzoate, ATZ = deprotonated 5-aminotetrazole, DMA = N,N-dimethylacetamide, and NMF = N-methylformamide), with uncoordinated N-donor sites and charged framework skeleton was fabricated. This MOF exhibits interesting structural dynamic upon CO2 sorption at 195 K and high CO2/N2 (127) and CO2/CH4 (131) sorption selectivity at 298 K and 1 bar. Particularly, its CO2/CH4 selectivity is among the highest MOFs for selective CO2 separation. The results of Grand Canonical Monte Carlo (GCMC) simulation indicate that the polar framework contributes to the strong framework-CO2 binding at zero loading, and the tetrazole pillar contributes to the high CO2 uptake capacity at high loading. Furthermore, the solvent-responsive luminescent properties of 1 indicate that it could be utilized as a fluorescent sensor to detect trace amounts of nitrobenzene in both solvent and vapor systems.

  2. A Chemical Role for Trichloromethane: Room-Temperature Removal of Coordinated Solvents from Open Metal Sites in the Copper-Based Metal-Organic Frameworks.

    Science.gov (United States)

    Choi, Jae Sun; Bae, Jinhee; Lee, Eun Ji; Jeong, Nak Cheon

    2018-04-17

    Open coordination sites (OCSs) in metal-organic frameworks (MOFs) have shown potential in applications such as molecular separation, sorption, catalysis, and sensing. Thus, the removal of coordinated solvent has been viewed as an essential step that needs to be performed prior to the use of the MOFs in the above applications. To date, a thermal method that is normally performed by applying heat and vacuum has been the most commonly employed activation method despite its negative influence on the structural integrity of the MOFs. In this report, we demonstrate that commonly inert trichloromethane (TCM) can activate OCSs; the TCM treatment process serves as an alternative chemical route to activation that does not require the external thermal energy. On the basis of the Raman study, we suggest a possible mechanism for the chemical activation process where TCM may weakly coordinate to the OCSs and then spontaneously dissociate. In addition, we prove that the chemical activation behavior is substantially boosted when a small amount of external heat energy (55 °C, 2.6 meV) is supplied during the TCM treatment. Using an HKUST-1-polyvinylidene fluoride (PVDF) mixed matrix (MM), we also demonstrate that this chemical activation strategy is a safe way to activate thermally deformable MOF-polymer mixed matrices.

  3. Synthesis of UiO-66-OH zirconium metal-organic framework and its application for selective extraction and trace determination of thorium in water samples by spectrophotometry

    Science.gov (United States)

    Moghaddam, Zahra Safaei; Kaykhaii, Massoud; Khajeh, Mostafa; Oveisi, Ali Reza

    2018-04-01

    In this study, a zirconium-based metal-organic framework (Zr-MOF), named UiO-66-OH, was synthesized by the solvo-thermal method and characterized by Fourier transform-infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). This Zr-MOF was then employed as a sorbent for selective extraction and preconcentration of thorium ions after their complexation with 2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxychromen-4-one (morin) from environmental water samples prior to its spectrophotometrical determination. The experimental parameters affecting extraction, such as pH of sample solution, amount of Zr-MOF, type and volume of eluting solvent, adsorption and desorption time, and concentration of complexing agent were evaluated and optimized. Under the optimized conditions, an enrichment factor of 250 was achieved. The limit of detection was calculated to be 0.35 μg·L- 1 with a linear range between 10 and 2000 μg·L- 1of thorium. The maximum sorption capacity of MOF toward thorium was found to be 47.5 mg·g- 1. The proposed procedure was successfully applied to the analysis of real water samples.

  4. Controlled Polymerization of Isoprene with Chromium-Based Metal-Organic Framework Catalysts: Switching from Cyclic to cis-1,4-Selectivity Depending on Activator.

    Science.gov (United States)

    Gao, Fei; Zhang, Li; Yu, Chao; Yan, Xinwen; Zhang, Shaowen; Li, Xiaofang

    2018-03-05

    Chromium-based metal-organic framework (MOF) Cr-MIL-100/101 activated by activator and aluminum trialkyl compound serve as unique, highly efficient heterogeneous single-site catalysts for the controlled polymerization of isoprene, which not only exhibit quasi-living nature in isoprene polymerization but also unprecedentedly switch from cyclic to cis-1,4-selectivity depending on the activator used to yield low molecular weight cyclic PIPs or extremely high molecular weight cis-1,4-PIPs. Such heterogeneous Cr-MOF catalysts can be recycled approximately five times. Based on nitrogen sorption isotherm tests and powder X-ray diffraction, a cationic mechanism is suggested, in which the polymerization takes place inside the open nanochannels of MOF catalysts and the space confinement effect of narrow open nanochannels originated from the coordination of PhNMe 2 from activator [PhNHMe 2 ][B(C 6 F 5 ) 4 ] with the multiple metal centers of MOF catalysts might give a rational explanation for such controlled adjustment on the PIP's structure and properties. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Glucose oxidase-initiated cascade catalysis for sensitive impedimetric aptasensor based on metal-organic frameworks functionalized with Pt nanoparticles and hemin/G-quadruplex as mimicking peroxidases.

    Science.gov (United States)

    Zhou, Xingxing; Guo, Shijing; Gao, Jiaxi; Zhao, Jianmin; Xue, Shuyan; Xu, Wenju

    2017-12-15

    Based on cascade catalysis amplification driven by glucose oxidase (GOx), a sensitive electrochemical impedimetric aptasensor for protein (carcinoembryonic antigen, CEA as tested model) was proposed by using Cu-based metal-organic frameworks functionalized with Pt nanoparticles, aptamer, hemin and GOx (Pt@CuMOFs-hGq-GOx). CEA aptamer loaded onto Pt@CuMOFs was bound with hemin to form hemin@G-quadruplex (hGq) with mimicking peroxidase activity. Through sandwich-type reaction of target CEA and CEA aptamers (Apt1 and Apt2), the obtained Pt@CuMOFs-hGq-GOx as signal transduction probes (STPs) was captured to the modified electrode interface. When 3,3-diaminobenzidine (DAB) and glucose were introduced, the cascade reaction was initiated by GOx to catalyze the oxidation of glucose, in situ generating H 2 O 2 . Simultaneously, the decomposition of the generated H 2 O 2 was greatly promoted by Pt@CuMOFs and hGq as synergistic peroxide catalysts, accompanying with the significant oxidation process of DAB and the formation of nonconductive insoluble precipitates (IPs). As a result, the electron transfer in the resultant sensing interface was effectively hindered and the electrochemical impedimetric signal (EIS) was efficiently amplified. Thus, the high sensitivity of the proposed CEA aptasensor was successfully improved with 0.023pgmL -1 , which may be promising and potential in assaying certain clinical disease related to CEA. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Self-assembly of cobalt-centered metal organic framework and multiwalled carbon nanotubes hybrids as a highly active and corrosion-resistant bifunctional oxygen catalyst

    Science.gov (United States)

    Fang, Yiyun; Li, Xinzhe; Li, Feng; Lin, Xiaoqing; Tian, Min; Long, Xuefeng; An, Xingcai; Fu, Yan; Jin, Jun; Ma, Jiantai

    2016-09-01

    Metal organic frameworks (MOF) derived carbonaceous materials have emerged as promising bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts for electrochemical energy conversion and storage. But previous attempts to overcome the poor electrical conductivity of MOFs hybrids involve a harsh high-template pyrolytic process to in situ form carbon, which suffer from extremely complex operation and inevitable carbon corrosion at high positive potentials when OER is operated. Herein, a self-assembly approach is presented to synthesize a non-precious metal-based, high active and strong durable Co-MOF@CNTs bifunctional catalyst for OER and ORR. CNTs not only improve the transportation of the electrons but also can sustain the harsh oxidative environment of OER without carbon corrosion. Meanwhile, the unique 3D hierarchical structure offers a large surface area and stable anchoring sites for active centers and CNTs, which enables the superior durability of hybrid. Moreover, a synergistic catalysis of Co(II), organic ligands and CNTs will enhance the bifunctional electrocatalytic performance. Impressively, the hybrid exhibits comparable OER and ORR catalytic activity to RuO2 and 20 wt% Pt/C catalysts and superior stability. This facile and versatile strategy to fabricating MOF-based hybrids may be extended to other electrode materials for fuel cell and water splitting applications.

  7. A high-capacitance flexible solid-state supercapacitor based on polyaniline and Metal-Organic Framework (UiO-66) composites

    Science.gov (United States)

    Shao, Liang; Wang, Qian; Ma, Zhonglei; Ji, Zhanyou; Wang, Xiaoying; Song, Doudou; Liu, Yuguo; Wang, Ni

    2018-03-01

    Metal-Organic Frameworks (MOFs) attract increasing attention in the field of energy storage, however, poor conductivity in most MOFs largely hinders their electrical properties. In this work, an effective strategy is developed to make the polyaniline (PANI) molecular chains grow in the pores of UiO-66 as one of the MOFs (labeled as PANI/UiO-66) to form a fixed interpenetrating network structure by using the highly stable porous MOFs, through a variety of synergistic effects to enhance the conductivity and electrochemical properties. Moreover, the design and analysis about PANI/UiO-66 is reported for the first time to our knowledge. In addition, PANI/UiO-66 exhibits an extraordinary capacitance of 1015 F g-1 at 1 A g-1 by electrochemical test. At the same time, the symmetric flexible solid-state supercapacitors is also assembled and tested. The resultant supercapacitor shows a favorable specific capacitance of 647 F g-1 at 1 A g-1 and a high cycling stability (91% capacitance retention after 5000 cycles). The bending test indicates that the obtained supercapacitor is flexible and its performance is only decreased 10% after 800 bending cycles with a bending angle of 180. This flexible solid-state supercapacitor shows great potential in energy storage device.

  8. Photoswitchable metal organic frameworks: turn on the lights and close the windows

    NARCIS (Netherlands)

    Castellanos Ortega, S.; Kapteijn, F.; Gascon Sabate, J.

    2016-01-01

    The ability of modulating the properties of metal–organic frameworks (MOF) on demand by external light-stimuli is a most appealing pathway to enhance their performance in storage and separation and to render novel advanced applications. Photoswitchable linkers of different nature have been inserted

  9. Separation of Hexane Isomers in a Metal-Organic Framework with Triangular Channels

    NARCIS (Netherlands)

    Herm, Z.R.; Wiers, B.M.; Mason, J.A.; van Baten, J.M.; Hudson, M.R.; Zajdel, P.; Brown, C.M.; Masciocchi, N.; Krishna, R.; Long, J.R.

    2013-01-01

    Metal-organic frameworks can offer pore geometries that are not available in zeolites or other porous media, facilitating distinct types of shape-based molecular separations. Here, we report Fe-2(BDP)(3) (BDP2- = 1,4-benzenedipyrazotate), a highly stable framework with triangular channels that

  10. Exploiting large-pore metal-organic frameworks for separations through entropic molecular mechanisms

    NARCIS (Netherlands)

    Torres-Knoop, A.; Dubbeldam, D.

    2015-01-01

    We review the molecular mechanisms behind adsorption and the separations of mixtures in metal-organic frameworks and zeolites. Separation mechanisms can be based on differences in the affinity of the adsorbate with the framework and on entropic effects. To develop next-generation adsorbents, the

  11. Enhanced Photochemical Hydrogen Production by a Molecular Diiron Catalyst Incorporated into a Metal-Organic Framework

    Energy Technology Data Exchange (ETDEWEB)

    Pullen, Sonja; Fei, Honghan; Orthaber, Andreas; Cohen, Seth M.; Ott, Sascha [Uppsala; (UCSD)

    2013-12-04

    A molecular proton reduction catalyst [FeFe](dcbdt)(CO)6 (1, dcbdt = 1,4-dicarboxylbenzene-2,3-dithiolate) with structural similarities to [FeFe]-hydrogenase active sites has been incorporated into a highly robust Zr(IV)-based metal–organic framework (MOF) by postsynthetic exchange (PSE). The PSE protocol is crucial as direct solvothermal synthesis fails to produce the functionalized MOF. The molecular integrity of the organometallic site within the MOF is demonstrated by a variety of techniques, including X-ray absorption spectroscopy. In conjunction with [Ru(bpy)3]2+ as a photosensitizer and ascorbate as an electron donor, MOF-[FeFe](dcbdt)(CO)6 catalyzes photochemical hydrogen evolution in water at pH 5. The immobilized catalyst shows substantially improved initial rates and overall hydrogen production when compared to a reference system of complex 1 in solution. Improved catalytic performance is ascribed to structural stabilization of the complex when incorporated in the MOF as well as the protection of reduced catalysts 1 and 12– from undesirable charge recombination with oxidized ascorbate.

  12. Trends in the adsorption of volatile organic compounds in a large-pore metal-organic framework, IRMOF-1.

    Science.gov (United States)

    Luebbers, Matthew T; Wu, Tianjiao; Shen, Lingjuan; Masel, Richard I

    2010-07-06

    Metal-organic frameworks have been proposed as useful sorbents for the capture of a variety of compounds. In this work, inverse gas chromatography (IGC) utilizing micropacked capillary columns was used to probe the adsorption of more than 30 volatile organic compounds (VOCs) on IRMOF-1. In an attempt to study the effect of structural degradation upon VOC adsorption, multiple samples of IRMOF-1 with widely ranging properties were investigated. Trends in the differential enthalpies and equilibrium constants for the adsorption of VOCs were determined on the basis of the molecular properties of the adsorbate and the structural properties of the MOF sample. The results indicate that samples of IRMOF-1 that are affected by a moderate amount of structural degradation interact with adsorbed species more strongly than does a sample with fewer defects, resulting in higher heats of adsorption. Samples of IRMOF-1 with specific surface areas of around 1000 m(2)/g show heats of adsorption for alkanes that are higher than those estimated previously via Monte Carlo calculations. Although the data for nonpolar (and weakly polar) species showed many of the anticipated trends for the interactions with IRMOF-1, the equilibrium behavior of polar VOCs did not correlate well with the molecular properties of the adsorbate (i.e., vapor pressure and deformation polarizability), leaving some uncertainty about the nature of the interaction mechanism. The equilibrium data and the heats of adsorption were found to fit well to a small group of molecular descriptors through the application of the Abraham linear free-energy relationship, thus providing insight into the complex interactions between the MOF structure and the VOC compounds. Hydrogen bonding interactions were determined to be the primary contributors to specific interactions between adsorbates and the MOF surface. Size exclusion also seems to play a role in the adsorption of larger species. These results show that the interaction of

  13. Determination of heavy metal ions in vegetable samples using a magnetic metal-organic framework nanocomposite sorbent.

    Science.gov (United States)

    Hassanpour, Akbar; Hosseinzadeh-Khanmiri, Rahim; Babazadeh, Mirzaagha; Abolhasani, Jafar; Ghorbani-Kalhor, Ebrahim

    2015-01-01

    This paper describes the synthesis and application of a novel magnetic metal-organic framework (MOF) [(Fe₃O₄-benzoyl isothiocyanate)/Cu₃(benzene-1,3,5-tricarboxylate)₂] to pre-concentrate trace amounts of Cd(II), Pb(II), Zn(II) and Cr(III) ions and their determination by flame atomic absorption spectrometry. A Box-Behnken design was used to find the parameters affecting the pre-concentration procedure through response surface methodology. Three factors including uptake time, amount of the magnetic sorbent and pH of the sample were selected as affecting factors in the sorption step, and four factors including type, volume and concentration of the eluent as well as the elution time were selected in the elution step for the optimisation study. The opted values were 30 mg, 10.1 min, 5.9, EDTA, 4.0 ml, 0.57 mol l(-1) EDTA solution and 13.0 min for the amount of the magnetic sorbent, uptake time, pH of the sample, type, volume, concentration of the eluent, and elution time, respectively. The limits of detection (LODs) were 0.12, 0.7, 0.16, and 0.4 ng ml(-1) for Cd(II), Pb(II), Zn(II) and Cr(III) ions, respectively. The relative standard deviations (RSDs) of the method were less than 7.2% for five separate batch experiments for the determination of 30 μg l(-1) of Cd(II), Pb(II), Zn(II) and Cr(III) ions. The sorption capacity of the [(Fe₃O₄-benzoyl isothiocyanate)/MOF] was 175 mg g(-1) for Cd(II), 168 mg g(-1) for Pb(II), 210 mg g(-1) for Zn(II) and 196 mg g(-1) for Cr(III). It was found that the magnetic MOF nanocomposite demonstrated a higher capacity compared with Fe₃O₄-benzoyl isothiocyanate. Finally, the magnetic MOF nanocomposite was successfully applied to the rapid extraction of trace amounts of the heavy metal ions from vegetable samples.

  14. Metal-Organic Frameworks Triggered High-Efficiency Li storage in Fe-Based Polyhedral Nanorods for Lithium-ion Batteries

    International Nuclear Information System (INIS)

    Shen, Lisha; Song, Huawei; Wang, Chengxin

    2017-01-01

    Recently, metal organic framework (MOF) nanostructures have been frequently reported in the field of energy storage, specifically for Li-ion or Na-ion storage. By inter-separating the active sites of metal cluster and organic ligands, MOF nanostructures are exceptionally promising for realizing fast ion exchange and high-efficiency transportation and addressing the intricate issues that the energy-intensive Li-ion batteries have faced over many years. The related ion-storage mechanism remains to be explored. Is the traditional redox reaction mechanism operative for these nanostructure, as it is for transitional metal oxide? Herein, taking [Fe 3 O(BDC) 3 (H 2 O) 2 (NO 3 )]n (Fe-MIL-88B) as an example, an Fe-based metal organic polyhedral nanorods of MIL–88 B structure was designed as an anode for Li-ion storage. When tested at 60 mA g −1 , the nanoporous Fe-MIL–88 B polyhedral nanorods retained a reversible capacity of 744.5 mAh g −1 for more than 400 cycles. Ex situ characterizations of the post-cycled electrodes revealed that both the transition metal ions and the organic ligands contributed to the high reversible specific capacity. The polyhedral nanorods electrodes held the metal-organic skeleton together throughout the battery operation, although in a somewhat different manner than the pristine ones. This further substantiated that some MOF nanostructures are more appropriate than others for stable lithiation/delithiation processes. State-of-the-art CR2032 full cells showed that a high capacity of 86.8 mAh g −1 that was retained after 100 cycles (herein, the capacity for the full cell was calculated based on both the weight of the anode and the cathode, and the charge-discharge rate was 0.25C), when commercial LiFePO 4 powders were used as the cathode.

  15. Using a Multi-Shelled Hollow Metal-Organic Framework as a Host to Switch the Guest-to-Host and Guest-to-Guest Interactions.

    Science.gov (United States)

    Liu, Xiao-Yuan; Zhang, Furui; Goh, Tian-Wei; Li, Yang; Shao, Yu-Cai; Luo, Lianshun; Huang, Wenyu; Long, Yi-Tao; Chou, Lien-Yang; Tsung, Chia-Kuang

    2018-02-19

    A bio-inspired design of using metal-organic framework (MOF) microcrystals with well-defined multi-shelled hollow structures was used as a matrix to host multiple guests including molecules and nanoparticles at separated locations to form a hierarchical material, mimicking biological structures. The interactions such as energy transfer (ET) between different guests are regulated by precisely fixing them in the MOF shells or encapsulating them in the cavities between the MOF shells. The proof-of-concept design is demonstrated by hosting chromophore molecules including rhodamine 6G (R6G) and 7-amino-4-(trifluoromethyl)coumarin (C-151), as well as metal nanoparticles (Pd NPs) into the multi-shelled hollow zeolitic imidazolate framework-8 (ZIF-8). We could selectively establish or diminish the guest-to-framework and guest-to-guest ET. This work provides a platform to construct complex multifunctional materials, especially those need precise separation control of multi-components. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Preparation and applications of monolithic structures containing metal-organic frameworks.

    Science.gov (United States)

    Lv, Yongqin; Tan, Xinyi; Svec, Frantisek

    2017-01-01

    Metal-organic frameworks are a new category of advanced porous materials with large surface areas and porosities, uniform pore sizes, tunable surface chemistry, and structural diversity. In combination with monoliths, they allow the fine tuning of desired interactions required in a variety of applications. This review article summarizes results of recent studies focused on synthetic strategies enabling incorporation of metal-organic frameworks in monolithic structures. A diverse array of applications including chromatographic separation, solid-phase microextraction, sample enrichment, heterogeneous catalysis, and enzymatic catalysis are also described. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. CFA-13 - a bifunctional perfluorinated metal-organic framework featuring active Cu(i) and Cu(ii) sites.

    Science.gov (United States)

    Fritzsche, J; Denysenko, D; Grzywa, M; Volkmer, D

    2017-11-07

    The synthesis and crystal structure of the mixed-valent perfluorinated metal-organic framework (Me 2 NH 2 )[CFA-13] (Coordination Framework Augsburg University-13), (Me 2 NH 2 )[CuCu(tfpc) 4 ] (H 2 -tfpc = 3,5-bis(trifluoromethyl)-1H-pyrazole-4-carboxylic acid) is described. The copper-containing MOF crystallizes in the monoclinic crystal system within the space group P2 1 /n (no. 14) and the unit cell parameters are as follows: a = 22.3887(19), b = 13.6888(8), c = 21.1804(13) Å, β = 90.495(3)°, V = 6491.0(8) Å 3 . (Me 2 NH 2 )[CFA-13] features a porous 3-D structure constructed from two types of secondary building units (SBUs). Besides novel trinuclear [Cu(pz) 4 ] - coordination units, the network also exhibits Cu(ii) paddle-wheel SBUs. (Me 2 NH 2 )[CFA-13] is fully characterized by single crystal X-ray diffraction, thermogravimetric analysis, variable temperature powder X-ray diffraction, IR spectroscopy, photoluminescence, gas sorption measurements and pulse chemisorption experiments. M[CFA-13] (M = K + , Cs + ) frameworks were prepared by postsynthetic exchange of interchannel dimethylammonium cations. Moreover, it was shown that CO molecules can be selectively bound at Cu(i) sites of [Cu(pz) 4 ] - units, whereas Cu(ii) paddle-wheel units bind selectively NH 3 molecules.

  18. A combined experimental and computational study of novel nanocage-based metal-organic frameworks for drug delivery.

    Science.gov (United States)

    Liu, Jian-Qiang; Li, Xue-Feng; Gu, Chu-Ying; da Silva, Júlio C S; Barros, Amanda L; Alves, Severino; Li, Bao-Hong; Ren, Fei; Batten, Stuart R; Soares, Thereza A

    2015-11-28

    Three new metal organic frameworks (MOFs) with chemical formulae [(CH3)2NH2] [Sm3(L1)2(HCOO)2(DMF)2(H2O)]·2DMF·18H2O (1), [Cu2(L2)(H2O)2]·2.22DMA (2) and [Zn2(L1)(DMA)]·1.75DMA were synthesized and structurally characterized. 1 and 2 show a classical NbO-like topology and have two types of interconnected cages. 3 exhibits an uncommon zzz topology and has two types of interconnected cages. These MOFs can adsorb large amounts of the drug 5-fluorouracil (5-FU) and release it in a progressive way. 5-FU was incorporated into desolvated 1, 2 and 3 with loadings of 0.40, 0.42, and 0.45 g g(-1), respectively. The drug release rates were 72%, 96% and 79% of the drug after 96 hours in 1, 120 hours in 2 and 96 hours in 3, respectively. Grand Canonical Monte Carlo (GCMC) simulations were performed to investigate the molecular interactions during 5-FU adsorption to the three novel materials. The GCMC simulations reproduced the experimental trend with respect to the drug loading capacity of each material. They also provided a structural description of drug packing within the frameworks, helping to explain the load capacity and controlled release characteristics of the materials. 5-FU binding preferences to 1, 2 and 3 reflect the diversity in pore types, chemistry and sizes. The calculated drug load is more related to the molecular properties of accessible volume Vacc than to the pore size.

  19. Enhanced Structural Support of Metal Sites as Nodes in Metal-Organic Frameworks Compared to Metal Complexes

    OpenAIRE

    Das, Sanjit

    2013-01-01

    Metal-organic frameworks are a new class of crystalline, porous solid-state materials with metal ions periodically linked by organic linkers. This gives rise to one-, two- or three-dimensional structures. Here, we compare the stability of similar metal sites toward external ligand (solvent) induced disruption of the coordination environment in metal complexes and in metal-organic frameworks. Our experimental results show that a metal site as node of a metal-organic framework retains much high...

  20. Potential of metal-organic frameworks for separation of xenon and krypton.

    Science.gov (United States)

    Banerjee, Debasis; Cairns, Amy J; Liu, Jian; Motkuri, Radha K; Nune, Satish K; Fernandez, Carlos A; Krishna, Rajamani; Strachan, Denis M; Thallapally, Praveen K

    2015-02-17

    dissolution in solvents and physisorption on porous materials. Physisorption-based separation and adsorption on highly functional porous materials are promising alternatives to the energy-intensive cryogenic distillation process, where the adsorbents are characterized by high surface areas and thus high removal capacities and often can be chemically fine-tuned to enhance the adsorbate-adsorbent interactions for optimum selectivity. Several traditional porous adsorbents such as zeolites and activated carbon have been tested for noble gas capture but have shown low capacity, selectivity, and lack of modularity. Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) are an emerging class of solid-state adsorbents that can be tailor-made for applications ranging from gas adsorption and separation to catalysis and sensing. Herein we give a concise summary of the background and development of Xe/Kr separation technologies with a focus on UNF reprocessing and the prospects of MOF-based adsorbents for that particular application.

  1. Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO_2 adsorption performance

    International Nuclear Information System (INIS)

    Sargazi, Ghasem; Afzali, Daryoush; Mostafavi, Ali; Ebrahimipour, S. Yousef

    2017-01-01

    This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2"k"-"1 factorial design experiments, and the response surface optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m"2/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO_2 adsorption. - Graphical abstract: A facile route was used for fabrication of a new metal -organic framework based on tantalum nanostructures that have high surface area, considerable porosity, homogenous morphology, and small size distribution.

  2. On the dielectric and optical properties of surface-anchored metal-organic frameworks: A study on epitaxially grown thin films

    Science.gov (United States)

    Redel, Engelbert; Wang, Zhengbang; Walheim, Stefan; Liu, Jinxuan; Gliemann, Hartmut; Wöll, Christof

    2013-08-01

    We determine the optical constants of two highly porous, crystalline metal-organic frameworks (MOFs). Since it is problematic to determine the optical constants for the standard powder modification of these porous solids, we instead use surface-anchored metal-organic frameworks (SURMOFs). These MOF thin films are grown using liquid phase epitaxy (LPE) on modified silicon substrates. The produced SURMOF thin films exhibit good optical properties; these porous coatings are smooth as well as crack-free, they do not scatter visible light, and they have a homogenous interference color over the entire sample. Therefore, spectroscopic ellipsometry (SE) can be used in a straightforward fashion to determine the corresponding SURMOF optical properties. After careful removal of the solvent molecules used in the fabrication process as well as the residual water adsorbed in the voids of this highly porous solid, we determine an optical constant of n = 1.39 at a wavelength of 750 nm for HKUST-1 (stands for Hong Kong University of Science and Technology-1; and was first discovered there) or [Cu3(BTC)2]. After exposing these SURMOF thin films to moisture/EtOH atmosphere, the refractive index (n) increases to n = 1.55-1.6. This dependence of the optical properties on water/EtOH adsorption demonstrates the potential of such SURMOF materials for optical sensing.

  3. Anchoring of Cu(II) onto surface of porous metal-organic framework through post-synthesis modification for the synthesis of benzimidazoles and benzothiazoles

    Energy Technology Data Exchange (ETDEWEB)

    Kardanpour, Reihaneh; Tangestaninejad, Shahram, E-mail: stanges@sci.ui.ac.ir; Mirkhani, Valiollah, E-mail: mirkhani@sci.ui.ac.ir; Moghadam, Majid, E-mail: moghadamm@sci.ui.ac.ir; Mohammadpoor-Baltork, Iraj; Zadehahmadi, Farnaz

    2016-03-15

    Efficient synthesis of various benzimidazoles and benzothiazoles under mild conditions catalyzed by Cu(II) anchored onto UiO-66–NH{sub 2} metal organic framework is reported. In this manner, first, the aminated UiO-66 was modified with thiophene-2-carbaldehyde and then the prepared Schiff base was reacted with CuCl{sub 2}. The prepared catalyst was characterized by FT-IR, UV–vis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N{sub 2} adsorption, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and field emission scanning electron microscopy (FE-SEM). The UiO-66–NH{sub 2}–TC–Cu was applied as a highly efficient catalyst for synthesis of benzimidazole and benzothiazole derivatives by the reaction of aldehydes with 1,2-diaminobenzene or 2-aminothiophenol. The Cu(II)-containing MOF was reused several times without any appreciable loss of its efficiency. - Graphical abstract: Efficient synthesis of benzimidazoles and benzothiazoles catalyzed by Cu(II) anchored onto UiO-66–NH{sub 2} metal organic framework is reported. - Highlights: • A copper Schiff base was immobilized on UiO-66 via postsynthetic modification. • The modified MOFs were fully characterized by a variety of methods. • The catalyst was used for the preparation of benzimidazoles and benzothiazoles. • In comparison of other catalysts, our catalyst was more efficient and forceful.

  4. Effect of the pillar ligand on preventing agglomeration of ZnO nanoparticles prepared from Zn(II metal-organic frameworks

    Directory of Open Access Journals (Sweden)

    Maryam Moeinian

    2016-01-01

    Full Text Available Metal-Organic Frameworks (MOFs represent a new class of highly porous materials. On this regard,  two nano porous metal-organic frameworks of [Zn2(1,4-bdc2(H2O2∙(DMF2]n (1 and [Zn2(1,4-bdc2(dabco]·4DMF·1⁄2H2O (2, (1,4-bdc = benzene-1,4-dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]octane and DMF = N,N-dimethylformamide were synthesized and characterized. They were used for preparation of ZnO nanomaterials. With calcination of 1, agglomerated ZnO nanoparticles could be fabricated, but by the same process on 2, the tendency of ZnO nanoparticles to agglomeration was decreased. In addition, the ZnO nanoparticles prepared from compound 2 had smaller diameter than those obtained from compound 1. In fact, the role of organic dabco ligands in 2 is similar to the role of polymeric stabilizers in formation of nanoparticles. Finally, considering the various applications of ZnO nanomaterials such as light-emitting diodes, photodetectors, photodiodes, gas sensors and dye-sensitized solar cells (DSSCs, it seems that preparation of ZnO nanomaterials from their MOFs could be one of the simple and effective methods which may be applied for preparation of them.

  5. Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO{sub 2} adsorption performance

    Energy Technology Data Exchange (ETDEWEB)

    Sargazi, Ghasem, E-mail: g.sargazi@gmail.com [Department of Nanotechnology Engineering, Mineral Industries Research Center, Shahid Bahonar University of Kerman, Kerman, Iran (Iran, Islamic Republic of); Young Researchers Society, Shahid Bahonar University of Kerman, Kerman, Iran (Iran, Islamic Republic of); Afzali, Daryoush, E-mail: daryoush_afzali@yahoo.com [Department of Nanotechnology, Graduate University of Advanced Technology, Kerman (Iran, Islamic Republic of); Mostafavi, Ali [Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran (Iran, Islamic Republic of); Ebrahimipour, S. Yousef [Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran (Iran, Islamic Republic of); Pistachio Safety Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran (Iran, Islamic Republic of)

    2017-06-15

    This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2{sup k-1} factorial design experiments, and the response surface optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m{sup 2}/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO{sub 2} adsorption. - Graphical abstract: A facile route was used for fabrication of a new metal -organic framework based on tantalum nanostructures that have high surface area, considerable porosity, homogenous morphology, and small size distribution.

  6. Novel metal-organic and supramolecular 3D frameworks constructed from flexible biphenyl-2,5,3‧-tricarboxylate blocks: Synthesis, structural features and properties

    Science.gov (United States)

    You, Ao; Li, Yu; Zhang, Ze-Min; Zou, Xun-Zhong; Gu, Jin-Zhong; Kirillov, Alexander M.; Chen, Jin-Wei; Chen, Yun-Bo

    2017-10-01

    Biphenyl-2,5,3‧-tricarboxylic acid (H3L) was selected as an unexplored tricarboxylate building block and applied for the hydrothermal synthesis of three novel coordination compounds, namely a 0D tetramer [Co4(HL)2(μ3-HL)2(phen)6(H2O)2]·3H2O (1) and two 3D metal-organic frameworks (MOFs) [Cd3(μ5-L)(μ6-L)(py)(μ-H2O)2(H2O)]n·H2O (2) and [Zn3(μ4-L)2(2,2‧-bpy)(μ-4,4‧-bpy)]n·2H2O (3). These products were easily generated in aqueous medium from the corresponding metal(II) chlorides, H3L, and various N-donor ancillary ligands, selected from 1,10-phenanthroline (phen), pyridine (py), 2,2‧-bipyridine (2,2‧-bpy), and 4,4‧-bipyridine (4,4‧-bpy). Compounds 1-3 were isolated as stable crystalline solids and were fully characterized by IR and UV-vis spectroscopy, elemental, thermogravimetric (TGA), powder (PXRD) and single-crystal X-ray diffraction analyses. Compound 1 possesses a discrete tetracobalt(II) structure, which is extended into a 3D H-bonded network with the pcu topology. In contrast, MOF 2 discloses a very complex trinodal 4,5,12-connected net with an undocumented topology, while MOF 3 features the nce/I topological framework. The magnetic (for 1) and luminescence (for 2 and 3) properties were also studied and discussed. The present study thus widens a still very limited family of metal-organic and supramolecular frameworks driven by flexible biphenyl-2,5,3‧-tricarboxylate building blocks.

  7. Separation of polar compounds using a flexible metal-organic framework

    NARCIS (Netherlands)

    Motkuri, R.K.; Thallapally, P.K.; Annapureddy, H.V.R.; Dang, L.X.; Krishna, R.; Nune, S.K.; Fernandez, C.A.; Liu, J.; McGrail, B.P.

    2015-01-01

    A flexible metal-organic framework constructed from a flexible linker is shown to possess the capability of separating mixtures of polar compounds (propanol isomers) by exploiting the differences in the saturation capacities of the constituents. Transient breakthrough simulations show that these

  8. Synthesis, characterization and sorption properties of zinc(II) metal-organic framework containing methanetetrabenzoate ligand

    Czech Academy of Sciences Publication Activity Database

    Almáši, M.; Zeleňák, V.; Gyepes, R.; Zukal, Arnošt; Čejka, Jiří

    2013-01-01

    Roč. 437, SI (2013), s. 101-107 ISSN 0927-7757 R&D Projects: GA ČR GA203/08/0604 Institutional support: RVO:61388955 Keywords : Metal-organic framework * Zinc * Methanetetrabenzoate Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.354, year: 2013

  9. Microporous metal-organic framework with potential for carbon dioxide capture at ambient conditions

    NARCIS (Netherlands)

    Xiang, S.C.; He, Y.; Zhang, Z.; Wu, H.; Zhou, W.; Krishna, R.; Chen, B.

    2012-01-01

    Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve

  10. Heme-Containing Metal-Organic Frameworks for the Oxidative Degradation of Chemical Warfare Agents

    Science.gov (United States)

    2016-04-14

    P.O. Box 12211 Research Triangle Park, NC 27709-2211 metal-organic frameworks, catalysis , metalloporphyrins, oxidation chemistry REPORT DOCUMENTATION...respectively; hydrogen atoms are omitted for clarity. ARO Final Progress Report...red, gray, bright green, and dark green represent Fe, N, O, C, F, and Cl respectively; hydrogen atoms omitted from clarity. Right: Diffuse

  11. Hydrocarbon separations in a metal-organic framework with open iron(II) coordination sites

    NARCIS (Netherlands)

    Bloch, E.D.; Queen, W.L.; Krishna, R.; Zadrozny, J. M.; Brown, C.M.; Long, J.R.

    2012-01-01

    The energy costs associated with large-scale industrial separation of light hydrocarbons by cryogenic distillation could potentially be lowered through development of selective solid adsorbents that operate at higher temperatures. Here, the metal-organic framework Fe2(dobdc) (dobdc4- :

  12. Functionalised metal-organic frameworks : A novel approach to stabilising single metal atoms

    NARCIS (Netherlands)

    Szilagyi, P.A.; Rogers, D. M.; Zaiser, I.; Callini, E; Turner, Stuart; Borgschulte, A; Züttel, A.; Geerlings, J.J.C.; Hirscher, M; Dam, B.

    2017-01-01

    We have investigated the potential of metal-organic frameworks for immobilising single atoms of transition metals using a model system of Pd supported on NH2-MIL-101(Cr). Our transmission electron microscopy and in situ Raman spectroscopy results give evidence for the first time that

  13. Metal-Organic Frameworks with d-f Cyanide Bridges: Structural Diversity, Bonding Regime, and Magnetism

    NARCIS (Netherlands)

    Ferbinteanu, M.; Cimpoesu, F.; Tanase, S.; Cheng, P.

    2015-01-01

    We present a selection of metal-organic frameworks based on d-f and f-f linkages, discussing their structural features and properties from experimental and theoretical viewpoints. We give an overview of our own synthetic and modeling methodologies, highlighting the complexity of the

  14. Catalytic behavior of metal-organic frameworks and zeolites: Rationalization and comparative analysis

    Czech Academy of Sciences Publication Activity Database

    Opanasenko, Maksym

    2015-01-01

    Roč. 243, APR 2015 (2015), s. 2-9 ISSN 0920-5861 R&D Projects: GA ČR GA14-07101S Institutional support: RVO:61388955 Keywords : Metal - organic frameworks * Zeolites * heterogeneous catalysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.312, year: 2015

  15. Enhanced adsorption selectivity of hydrogen/methane mixtures in metal-organic frameworks with interpenetration: A molecular simulation study

    NARCIS (Netherlands)

    Liu, B.; Yang, Q.; Xue, C.; Zhong, C.; Chen, B.; Smit, B.

    2008-01-01

    In this work a systematic molecular simulation study was performed to study the effect of interpenetration on gas mixture separation in metal−organic frameworks (MOFs). To do this, three pairs of isoreticular MOFs (IRMOFs) with and without interpenetration were adopted to compare their adsorption

  16. A novel magnetic metal organic framework nanocomposite for extraction and preconcentration of heavy metal ions, and its optimization via experimental design methodology

    International Nuclear Information System (INIS)

    Taghizadeh, Mohsen; Asgharinezhad, Ali Akbar; Pooladi, Mohsen; Barzin, Mahnaz; Abbaszadeh, Abolfazl; Tadjarodi, Azadeh

    2013-01-01

    We describe a novel magnetic metal-organic framework (MOF) prepared from dithizone-modified Fe 3 O 4 nanoparticles and a copper-(benzene-1,3,5-tricarboxylate) MOF and its use in the preconcentration of Cd(II), Pb(II), Ni(II), and Zn(II) ions. The parameters affecting preconcentration were optimized by a Box-Behnken design through response surface methodology. Three variables (extraction time, amount of the magnetic sorbent, and pH value) were selected as the main factors affecting adsorption, while four variables (type, volume and concentration of the eluent; desorption time) were selected for desorption in the optimization study. Following preconcentration and elution, the ions were quantified by FAAS. The limits of detection are 0.12, 0.39, 0.98, and 1.2 ng mL −1 for Cd(II), Zn(II), Ni(II), and Pb(II) ions, respectively. The relative standard deviations were −1 of Cd(II), Zn(II), Ni(II), and Pb(II) ions. The adsorption capacities (in mg g −1 ) of this new MOF are 188 for Cd(II), 104 for Pb(II), 98 Ni(II), and 206 for Zn(II). The magnetic MOF nanocomposite has a higher capacity than the Fe 3 O 4 /dithizone conjugate. This magnetic MOF nanocomposite was successfully applied to the rapid extraction of trace quantities of heavy metal ions in fish, sediment, soil, and water samples. (author)

  17. Fluorescent molecule incorporated metal-organic framework for fluoride sensing in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xudong, E-mail: zhaoxd_tykj@163.com; Wang, Yuanyang; Hao, Xiuli; Liu, Wen, E-mail: 13700509372@163.com

    2017-04-30

    Highlights: • Fluorescein sodium was successfully encapsulated in UiO-66 via in-situ synthesis. • FS@UiO-66 is one of the few Zr-MOF-based probes for fluoride so far. • FS@UiO-66 is a highly effective, fast-response and naked-eye sensor for fluoride. - Abstract: In this work, the fluorescent molecule (fluorescein sodium, FS) was successfully incorporated in the zirconium-based MOF (UiO-66) via in-situ synthesis method, which can be confirmed by FTIR spectra and fluorescence microscopic images. Based on this in-situ synthesis strategy, FS molecule can be immobilized tightly in the framework. Furthermore, the resulting FS@UiO-66 demonstrates to be a highly selective, real-time and naked-eye chemical sensor for fluoride in aqueous solution, which is mainly due to the release of FS molecule from FS@UiO-66 into the aqueous solution. Meanwhile, to the best of our knowledge, such Zr-MOF-based fluoride sensor is very rare so far. These results provide a promising approach to rationally design novel MOF-based fluorescent sensor for the target molecules.

  18. Polymer-Derived Silicoboron Carbonitride Foams for CO2 Capture: From Design to Application as Scaffolds for the in Situ Growth of Metal-Organic Frameworks.

    Science.gov (United States)

    Sandra, Fabien; Depardieu, Martin; Mouline, Zineb; Vignoles, Gérard L; Iwamoto, Yuji; Miele, Philippe; Backov, Rénal; Bernard, Samuel

    2016-06-06

    A template-assisted polymer-derived ceramic route is investigated for preparing a series of silicoboron carbonitride (Si/B/C/N) foams with a hierarchical pore size distribution and tailorable interconnected porosity. A boron-modified polycarbosilazane was selected to impregnate monolithic silica and carbonaceous templates and form after pyrolysis and template removal Si/B/C/N foams. By changing the hard template nature and controlling the quantity of polymer to be impregnated, controlled micropore/macropore distributions with mesoscopic cell windows are generated. Specific surface areas from 29 to 239 m(2)  g(-1) and porosities from 51 to 77 % are achieved. These foams combine a low density with a thermal insulation and a relatively good thermostructural stability. Their particular structure allowed the in situ growth of metal-organic frameworks (MOFs) directly within the open-cell structure. MOFs offered a microporosity feature to the resulting Si/B/C/N@MOF composite foams that allowed increasing the specific surface area to provide CO2 uptake of 2.2 %. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Guest Induced Strong Cooperative One- and Two-Step Spin Transitions in Highly Porous Iron(II) Hofmann-Type Metal-Organic Frameworks.

    Science.gov (United States)

    Piñeiro-López, Lucı A; Valverde-Muñoz, Francisco Javier; Seredyuk, Maksym; Muñoz, M Carmen; Haukka, Matti; Real, José Antonio

    2017-06-19

    The synthesis, crystal structure, magnetic, calorimetric, and Mössbauer studies of a series of new Hofmann-type spin crossover (SCO) metal-organic frameworks (MOFs) is reported. The new SCO-MOFs arise from self-assembly of Fe II , bis(4-pyridyl)butadiyne (bpb), and [Ag(CN) 2 ] - or [M II (CN) 4 ] 2- (M II = Ni, Pd). Interpenetration of four identical 3D networks with α-Po topology are obtained for {Fe(bpb)[Ag I (CN) 2 ] 2 } due to the length of the rod-like bismonodentate bpb and [Ag(CN) 2 ] - ligands. The four networks are tightly packed and organized in two subsets orthogonally interpenetrated, while the networks in each subset display parallel interpenetration. This nonporous material undergoes a very incomplete SCO, which is rationalized from its intricate structure. In contrast, the single network Hofmann-type MOFs {Fe(bpb)[M II (CN) 4 ]}·nGuest (M II = Ni, Pd) feature enhanced porosity and display complete one-step or two-step cooperative SCO behaviors when the pores are filled with two molecules of nitrobenzene or naphthalene that interact strongly with the pyridyl and cyano moieties of the bpb ligands via π-π stacking. The lack of these guest molecules favors stabilization of the high-spin state in the whole range of temperatures. However, application of hydrostatic pressure induces one- and two-step SCO.

  20. Reversible Single-Crystal-to-Single-Crystal Structural Transformation in a Mixed-Ligand 2D Layered Metal-Organic Framework: Structural Characterization and Sorption Study

    Directory of Open Access Journals (Sweden)

    Chih-Chieh Wang

    2017-12-01

    Full Text Available A 3D supramolecular network, [Cd(bipy(C4O4(H2O2]·3H2O (1 (bipy = 4,4′-bipyridine and C4O42− = dianion of H2C4O4, constructed by mixed-ligand two-dimensional (2D metal-organic frameworks (MOFs has been reported and structurally determined by the single-crystal X-ray diffraction method and characterized by other physicochemical methods. In 1, the C4O42− and bipy both act as bridging ligands connecting the Cd(II ions to form a 2D layered MOF, which are then extended to a 3D supramolecular network via the mutually parallel and interpenetrating arrangements among the 2D-layered MOFs. Compound 1 shows a two-step dehydration process with weight losses of 11.0% and 7.3%, corresponding to the weight-loss of three guest and two coordinated water molecules, respectively, and exhibits an interesting reversible single-crystal-to-single-crystal (SCSC structural transformation upon de-hydration and re-hydration for guest water molecules. The SCSC structural transformation have been demonstrated and monitored by single-crystal and X-ray powder diffraction, and thermogravimetic analysis studies.

  1. Giant negative linear compression positively coupled to massive thermal expansion in a metal-organic framework.

    Science.gov (United States)

    Cai, Weizhao; Katrusiak, Andrzej

    2014-07-04

    Materials with negative linear compressibility are sought for various technological applications. Such effects were reported mainly in framework materials. When heated, they typically contract in the same direction of negative linear compression. Here we show that this common inverse relationship rule does not apply to a three-dimensional metal-organic framework crystal, [Ag(ethylenediamine)]NO3. In this material, the direction of the largest intrinsic negative linear compression yet observed in metal-organic frameworks coincides with the strongest positive thermal expansion. In the perpendicular direction, the large linear negative thermal expansion and the strongest crystal compressibility are collinear. This seemingly irrational positive relationship of temperature and pressure effects is explained and the mechanism of coupling of compressibility with expansivity is presented. The positive coupling between compression and thermal expansion in this material enhances its piezo-mechanical response in adiabatic process, which may be used for designing new artificial composites and ultrasensitive measuring devices.

  2. Porous carbon-coated ZnO nanoparticles derived from low carbon content formic acid-based Zn(II) metal-organic frameworks towards long cycle lithium-ion anode material

    International Nuclear Information System (INIS)

    Gao, Song; Fan, Ruiqing; Li, Bingjiang; Qiang, Liangsheng; Yang, Yulin

    2016-01-01

    Graphical abstract: The nanocomposites constructed from Zn-based MOFs exhibit low carbon content with super-high rate capability and long cycling life. - Highlights: • Novel ZnO@porous carbon matrix nanocomposites are constructed by pyrolysis of Zn-based MOFs. • The nanocomposites constructed with Zn-based MOFs show low carbon content. • The constructed nanocomposites exhibit high energy density, super-high rate capability and long cycling life. - Abstract: Single-C formic acid-based metal-organic frameworks (MOFs) are used to construct novel ZnO@porous carbon matrix nanocomposites by controlled pyrolysis. In the constructed nanocomposites, the porous carbon matrices act as a confined support to prevent agglomeration of the ZnO nanoparticles and create a rapid electron conductive network. Meanwhile, the well-defined, continuous porous structured MOFs provide a large specific surface area, which increases the contact of electrolyte-electrode and improves the penetration of electrolyte. Especially, the reasonable choice of formic acid-based MOFs construct the low carbon content composite, which contribute to the high energy density and long cycle life. The constructed nanocomposites show stable, ultrahigh rate lithium ion storage properties of 650 mAh g −1 at charge/discharge rate of 1 C even after 200 cycles.

  3. Synthesis of hierarchical porous carbon monoliths with incorporated metal-organic frameworks for enhancing volumetric based CO₂ capture capability.

    Science.gov (United States)

    Qian, Dan; Lei, Cheng; Hao, Guang-Ping; Li, Wen-Cui; Lu, An-Hui

    2012-11-01

    This work aims to optimize the structural features of hierarchical porous carbon monolith (HCM) by incorporating the advantages of metal-organic frameworks (MOFs) (Cu₃(BTC)₂) to maximize the volumetric based CO₂ capture capability (CO₂ capacity in cm³ per cm³ adsorbent), which is seriously required for the practical application of CO₂ capture. The monolithic HCM was used as a matrix, in which Cu₃(BTC)₂ was in situ synthesized, to form HCM-Cu₃(BTC)₂ composites by a step-by-step impregnation and crystallization method. The resulted HCM-Cu₃(BTC)₂ composites, which retain the monolithic shape and exhibit unique hybrid structure features of both HCM and Cu₃(BTC)₂, show high CO₂ uptake of 22.7 cm³ cm⁻³ on a volumetric basis. This value is nearly as twice as the uptake of original HCM. The dynamic gas separation measurement of HCM-Cu₃(BTC)₂, using 16% (v/v) CO₂ in N₂ as feedstock, illustrates that CO₂ can be easily separated from N₂ under the ambient conditions and achieves a high separation factor for CO₂ over N₂, ranging from 67 to 100, reflecting a strongly competitive CO₂ adsorption by the composite. A facile CO₂ release can be realized by purging an argon flow through the fixed-bed adsorber at 25 °C, indicating the good regeneration ability.

  4. Chromium-based metal-organic framework MIL-101 as a highly effective catalyst in plasma for toluene removal

    Science.gov (United States)

    Wu, Junliang; Xia, Qibin; Xiao, Jing; Li, Zhong

    2017-11-01

    Catalytic performance of MIL-101—a type of chromium-based metal-organic frameworks (MOFs)—in a plasma catalysis system for toluene removal was experimentally studied. The MIL-101 was synthesized using a hydrothermal method, and its catalytic performance was compared to two other catalysts, Cr2O3/γ-Al2O3 and γ-Al2O3, in a dielectric barrier discharge (DBD) reactor. Results showed that the presence of a catalyst in plasma changed the voltage and current characteristic substantially, and promoted the performance of the plasma reactor. Among the catalysts, the MIL-101 exhibited a significantly high toluene conversion, which was 20% and 35% higher than Cr2O3/γ-Al2O3 and γ-Al2O3, respectively, under the same testing conditions, as well as higher carbon balance and CO2 selectivity. The analysis of by-products on the surfaces of the catalysts before and after reaction demonstrated that MIL-101 had better resistance towards by-products accumulation compared to Cr2O3/γ-Al2O3 and γ-Al2O3. The loading of MnO x on MIL-101 further promoted its catalytic performance. MIL-101 exhibits attractive catalytic properties as a catalyst in a plasma catalysis system for the decomposition of volatile organic compounds.

  5. Chromium-based metal-organic framework MIL-101 as a highly effective catalyst in plasma for toluene removal

    International Nuclear Information System (INIS)

    Wu, Junliang; Xia, Qibin; Xiao, Jing; Li, Zhong

    2017-01-01

    Catalytic performance of MIL-101—a type of chromium-based metal-organic frameworks (MOFs)—in a plasma catalysis system for toluene removal was experimentally studied. The MIL-101 was synthesized using a hydrothermal method, and its catalytic performance was compared to two other catalysts, Cr 2 O 3 / γ -Al 2 O 3 and γ -Al 2 O 3 , in a dielectric barrier discharge (DBD) reactor. Results showed that the presence of a catalyst in plasma changed the voltage and current characteristic substantially, and promoted the performance of the plasma reactor. Among the catalysts, the MIL-101 exhibited a significantly high toluene conversion, which was 20% and 35% higher than Cr 2 O 3 / γ -Al 2 O 3 and γ -Al 2 O 3 , respectively, under the same testing conditions, as well as higher carbon balance and CO 2 selectivity. The analysis of by-products on the surfaces of the catalysts before and after reaction demonstrated that MIL-101 had better resistance towards by-products accumulation compared to Cr 2 O 3 / γ -Al 2 O 3 and γ -Al 2 O 3 . The loading of MnO x on MIL-101 further promoted its catalytic performance. MIL-101 exhibits attractive catalytic properties as a catalyst in a plasma catalysis system for the decomposition of volatile organic compounds. (paper)

  6. Preparation and characterization of metal-organic framework MIL-101(Cr)-coated solid-phase microextraction fiber.

    Science.gov (United States)

    Xie, Lijun; Liu, Shuqin; Han, Zhubing; Jiang, Ruifen; Liu, Hong; Zhu, Fang; Zeng, Feng; Su, Chengyong; Ouyang, Gangfeng

    2015-01-01

    Metal-organic frameworks (MOFs) have received great attention as novel sorbents due to their fascinating structures and intriguing potential applications in various fields. In this work, a MIL-101(Cr)-coated solid-phase microextraction (SPME) fiber was fabricated by a simple direct coating method and applied to the determination of volatile compounds (BTEX, benzene, toluene, ethylbenzene, m-xylene and o-xylene) and semi-volatile compounds (PAHs, polycyclic aromatic hydrocarbons) from water samples. The extraction and desorption conditions of headspace SPME (HS-SPME) were optimized. Under the optimized conditions, the established methods exhibited excellent extraction performance. Good precision (<7.7%) and low detection limits (0.32-1.7 ng L(-1) and 0.12-2.1 ng L(-1) for BTEX and PAHs, respectively) were achieved. In addition, the MIL-101(Cr)-coated fiber possessed good thermal stability, and the fiber can be reused over 150 times. The fiber was successfully applied to the analysis of BTEX and PAHs in river water by coupling with gas chromatography-mass spectrometry (GC-MS). The analytes at low concentrations (1.7 and 10 ng L(-1)) were detected, and the recoveries obtained with the spiked river water samples were in the range of 80.0-113% and 84.8-106% for BTEX and PAHs, respectively, which demonstrated the applicability of the self-made fiber. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Co3O4 Electrode Prepared by Using Metal-Organic Framework as a Host for Supercapacitors

    Directory of Open Access Journals (Sweden)

    Jiaqiang Jiang

    2015-01-01

    Full Text Available Co3O4 nanoparticles were prepared from cobalt nitrate that was accommodated in the pores of a metal-organic framework (MOF ZIF-8 (Zn(MeIM2, MeIM = 2-methylimidazole by using a simple liquid-phase method. Analysis by scanning electron microscopy (SEM and transmission electron microscopy (TEM showed that the obtained Co3O4 was composed of separate nanoparticles with a mean size of 30 nm. The obtained Co3O4 nanoparticles exhibited superior electrochemical property. Co3O4 electrode exhibited a maximum specific capacitance of 189.1 F g−1 at the specific current of 0.2 A g−1. Meanwhile, the Co3O4 electrode possessed the high specific capacitance retention ratio at the current density ranging from 0.2 to 1.0 A g−1, thereby indicating that Co3O4 electrode suited high-rate charge/discharge.

  8. Polystyrene Sulfonate Threaded through a Metal-Organic Framework Membrane for Fast and Selective Lithium-Ion Separation.

    Science.gov (United States)

    Guo, Yi; Ying, Yulong; Mao, Yiyin; Peng, Xinsheng; Chen, Banglin

    2016-11-21

    Extraction of lithium ions from salt-lake brines is very important to produce lithium compounds. Herein, we report a new approach to construct polystyrene sulfonate (PSS) threaded HKUST-1 metal-organic framework (MOF) membranes through an in situ confinement conversion process. The resulting membrane PSS@HKUST-1-6.7, with unique anchored three-dimensional sulfonate networks, shows a very high Li + conductivity of 5.53×10 -4  S cm -1 at 25 °C, 1.89×10 -3  S cm -1 at 70 °C, and Li + flux of 6.75 mol m -2  h -1 , which are five orders higher than that of the pristine HKUST-1 membrane. Attributed to the different size sieving effects and the affinity differences of the Li + , Na + , K + , and Mg 2+ ions to the sulfonate groups, the PSS@HKUST-1-6.7 membrane exhibits ideal selectivities of 78, 99, and 10296 for Li + /Na + , Li + /K + , Li + /Mg 2+ and real binary ion selectivities of 35, 67, and 1815, respectively, the highest ever reported among ionic conductors and Li + extraction membranes. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Synthesis of Framework Isomer MOFs Containing Zinc and 4-Tetrazolyl Benzenecarboxylic Acid via a Structure Directing Solvothermal Approach

    Directory of Open Access Journals (Sweden)

    Carlos Ordonez

    2015-04-01

    Full Text Available The solvothermal synthesis of framework isomers was carried out using the hybrid carboxylate and tetrazolate functional ligand, 4-tetrazolyl benzenecarboxylic acid (H2TBC, TBC = 4-tetrazolyl benzenecarboxylate and zinc. H2TBC was also synthesized with the solvothermal approach, and is referred herein as structure 1. Using single-crystal X-ray diffraction, we found that the tetrazolate groups of TBC show an unusual “opposite-on” coordination mode with zinc. Three previously characterized metal-organic frameworks (MOFs were obtained by systematically changing the solvents of the H2TBC-Zn reaction, (1 ZnTBC, 2, which has a non-porous structure; (2 Zn2(TBC2(H2O, 3, which has an amphiphilic pore structure and (3 Zn2(TBC2{guest}, 4, which is porous and has channels containing uncoordinated N heteroatoms. Fluorescence spectra of 4 reveal a strong blue emission mainly from the TBC ligands.

  10. High-Density Energetic Metal-Organic Frameworks Based on the 5,5'-Dinitro-2H,2'H-3,3'-bi-1,2,4-triazole.

    Science.gov (United States)

    Dong, Yalu; Peng, Panpan; Hu, Baoping; Su, Hui; Li, Shenghua; Pang, Siping

    2017-06-26

    High-energy metal-organic frameworks (MOFs) based on nitrogen-rich ligands are an emerging class of explosives, and density is one of the positive factors that can influence the performance of energetic materials. Thus, it is important to design and synthesize high-density energetic MOFs. In the present work, hydrothermal reactions of Cu(II) with the rigid polynitro heterocyclic ligands 5,5'-dinitro-2 H ,2' H -3,3'-bi-1,2,4-triazole (DNBT) and 5,5'-dinitro-3,3'-bis-1,2,4-triazole-1-diol (DNBTO) gave two high-density MOFs: [Cu(DNBT)(ATRZ)₃] n ( 1 ) and [Cu(DNBTO)(ATRZ)₂(H₂O)₂] n ( 2 ), where ATRZ represents 4,4'-azo-1,2,4-triazole. The structures were characterized by infrared spectroscopy, elemental analysis, ultraviolet-visible (UV) absorption spectroscopy and single-crystal X-ray diffraction. Their thermal stabilities were also determined by thermogravimetric/differential scanning calorimetry analysis (TG/DSC). The results revealed that complex 1 has a two-dimensional porous framework that possesses the most stable chair conformations (like cyclohexane), whereas complex 2 has a one-dimensional polymeric structure. Compared with previously reported MOFs based on copper ions, the complexes have higher density (ρ = 1.93 g cm -3 for complex 1 and ρ = 1.96 g cm -3 for complex 2 ) and high thermal stability (decomposition temperatures of 323 °C for complex 1 and 333.3 °C for complex 2 ), especially because of the introduction of an N-O bond in complex 2 . We anticipate that these two complexes would be potential high-energy density materials.

  11. Bipyridine- and phenanthroline-based metal-organic frameworks for highly efficient and tandem catalytic organic transformations via directed C-H activation

    Energy Technology Data Exchange (ETDEWEB)

    Manna, Kuntal [Univ. of Chicago, Chicago, IL (United States); Zhang, Teng [Univ. of Chicago, Chicago, IL (United States); Greene, Francis X. [Univ. of Chicago, Chicago, IL (United States); Lin, Wenbin [Univ. of Chicago, Chicago, IL (United States)

    2015-02-16

    We report here the synthesis of a series of robust and porous bipyridyl- and phenanthryl-based metal–organic frameworks (MOFs) of UiO topology (BPV-MOF, mBPV-MOF, and mPT-MOF) and their postsynthetic metalation to afford highly active single-site solid catalysts. While BPV-MOF was constructed from only bipyridyl-functionalized dicarboxylate linker, both mBPV- and mPT-MOF were built with a mixture of bipyridyl- or phenanthryl-functionalized and unfunctionalized dicarboxylate linkers. The postsynthetic metalation of these MOFs with [Ir(COD)(OMe)]2 provided Ir-functionalized MOFs (BPV-MOF-Ir, mBPV-MOF-Ir, and mPT-MOF-Ir), which are highly active catalysts for tandem hydrosilylation of aryl ketones and aldehydes followed by dehydrogenative ortho-silylation of benzylicsilyl ethers as well as C–H borylation of arenes using B₂pin₂. Both mBPV-MOF-Ir and mPT-MOF-Ir catalysts displayed superior activities compared to BPV-MOF-Ir due to the presence of larger open channels in the mixed-linker MOFs. Impressively, mBPV-MOF-Ir exhibited high TONs of up to 17000 for C–H borylation reactions and was recycled more than 15 times. The mPT-MOF-Ir system is also active in catalyzing tandem dehydrosilylation/dehydrogenative cyclization of N-methylbenzyl amines to azasilolanes in the absence of a hydrogen acceptor. Importantly, MOF-Ir catalysts are significantly more active (up to 95 times) and stable than their homogeneous counterparts for all three reactions, strongly supporting the beneficial effects of active site isolation within MOFs. This work illustrates the ability to increase MOF open channel sizes by using the mixed linker approach and shows the enormous potential of developing highly active and robust single-site solid catalysts based on MOFs containing nitrogen-donor ligands for important organic transformations.

  12. Gas adsorption and gas mixture separations using mixed-ligand MOF material

    Science.gov (United States)

    Hupp, Joseph T [Northfield, IL; Mulfort, Karen L [Chicago, IL; Snurr, Randall Q [Evanston, IL; Bae, Youn-Sang [Evanston, IL

    2011-01-04

    A method of separating a mixture of carbon dioxiode and hydrocarbon gas using a mixed-ligand, metal-organic framework (MOF) material having metal ions coordinated to carboxylate ligands and pyridyl ligands.

  13. Microporous metal-organic framework with potential for carbon dioxide capture at ambient conditions.

    Science.gov (United States)

    Xiang, Shengchang; He, Yabing; Zhang, Zhangjing; Wu, Hui; Zhou, Wei; Krishna, Rajamani; Chen, Banglin

    2012-07-17

    Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve such separations and to replace current technologies, which use aqueous solvents to chemically absorb carbon dioxide. Here we show that a metal-organic frameworks (UTSA-16) displays high uptake (160 cm(3) cm(-3)) of CO(2) at ambient conditions, making it a potentially useful adsorbent material for post-combustion carbon dioxide capture and biogas stream purification. This has been further confirmed by simulated breakthrough experiments. The high storage capacities and selectivities of UTSA-16 for carbon dioxide capture are attributed to the optimal pore cages and the strong binding sites to carbon dioxide, which have been demonstrated by neutron diffraction studies.

  14. Manipulating Light with Transition Metal Clusters, Organic Dyes, and Metal Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Ogut, Serdar [Univ. of Illinois, Chicago, IL (United States)

    2017-09-11

    The primary goals of our research program is to develop and apply state-of-the-art first-principles methods to predict electronic and optical properties of three systems of significant scientific and technological interest: transition metal clusters, organic dyes, and metal-organic frameworks. These systems offer great opportunities to manipulate light for a wide ranging list of energy-related scientific problems and applications. During this grant period, we focused our investigations on the development, implementation, and benchmarking of many-body Green’s function methods (GW approximation and the Bethe-Salpeter equation) to examine excited-state properties of transition metal/transition-metal-oxide clusters and organic molecules that comprise the building blocks of dyes and metal-organic frameworks.

  15. Nanosizing a Metal-Organic Framework Enzyme Carrier for Accelerating Nerve Agent Hydrolysis

    Science.gov (United States)

    2016-10-05

    electron microscopy images of NU-1003 crystals with lengths of (a) 300, (b) 1000, (c) 2000, (d) 7000, and (e) 10000 nm. (f) PXRD patterns of different...1003 is filled by OPAA, while the micropores are relatively unoccupied. The PXRD patterns (Figure S5) and scanning electron microscopy (SEM) images...Encapsulation of a Nerve Agent Detoxifying Enzyme by a Mesoporous Zirconium Metal-Organic Framework Engenders Ther- mal and Long-Term Stability. J. Am

  16. Self-Exfoliated Metal-Organic Nanosheets through Hydrolytic Unfolding of Metal-Organic Polyhedra.

    Science.gov (United States)

    Garai, Bikash; Mallick, Arijit; Das, Anuja; Mukherjee, Rabibrata; Banerjee, Rahul

    2017-05-29

    Few-layers thick metal-organic nanosheets have been synthesized using water-assisted solid-state transformation through a combined top-down and bottom-up approach. The metal-organic polyhedra (MOPs) convert into metal-organic frameworks (MOFs) which subsequently self-exfoliate into few-layered metal-organic nanosheets. These MOP crystals experience a hydrophobicity gradient with the inner surface during contact with water because of the existence of hydrophobic spikes on their outer surface. When the amount of water available for interaction is higher, the resultant layers are not stacked to form bulk materials; instead few-layered nanosheets with high uniformity were obtained in high yield. The phenomenon has resulted high yield production of uniformly distributed layered metal-organic nanosheets from three different MOPs, showing its general adaptability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Increased Thermal Conductivity in Metal-Organic Heat Carrier Nanofluids

    OpenAIRE

    Manjula I. Nandasiri; Jian Liu; B. Peter McGrail; Jeromy Jenks; Herbert T. Schaef; Vaithiyalingam Shutthanandan; Zimin Nie; Paul F. Martin; Satish K. Nune

    2016-01-01

    Metal-organic heat carriers (MOHCs) are recently developed nanofluids containing metal-organic framework (MOF) nanoparticles dispersed in various base fluids including refrigerants (R245Fa) and methanol. Here, we report the synthesis and characterization of MOHCs containing nanoMIL-101(Cr) and graphene oxide (GO) in an effort to improve the thermo-physical properties of various base fluids. MOHC/GO nanocomposites showed enhanced surface area, porosity, and nitrogen adsorption compared with th...

  18. Electrochemical Water Oxidation by a Catalyst-Modified Metal-Organic Framework Thin Film

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shaoyang; Pineda-Galvan, Yuliana; Maza, William A.; Epley, Charity C.; Zhu, Jie; Kessinger, Matthew C.; Pushkar, Yulia; Morris, Amanda J. (VP); (Purdue)

    2016-12-15

    Water oxidation, a key component in artificial photosynthesis, requires high overpotentials and exhibits slow reaction kinetics that necessitates the use of stable and efficient heterogeneous water-oxidation catalysts (WOCs). Here, we report the synthesis of UiO-67 metal–organic framework (MOF) thin films doped with [Ru(tpy)(dcbpy)OH2]2+ (tpy=2,2':6',2''-terpyridine, dcbpy=5,5'-dicarboxy-2,2'-bipyridine) on conducting surfaces and their propensity for electrochemical water oxidation. The electrocatalyst oxidized water with a turnover frequency (TOF) of (0.2±0.1) s-1 at 1.71 V versus the normal hydrogen electrode (NHE) in buffered solution (pH~7) and exhibited structural and electrochemical stability. The electroactive sites were distributed throughout the MOF thin film on the basis of scan-ratedependent voltammetry studies. This work demonstrates a promising way to immobilize large concentrations of electroactive WOCs into a highly robust MOF scaffold and paves the way for future photoelectrochemical water-splitting systems.

  19. An in situ study of resin-assisted solvothermal metal-organic framework synthesis

    International Nuclear Information System (INIS)

    Moorhouse, Saul J.; Wu, Yue; O’Hare, Dermot

    2016-01-01

    A newly developed in situ monochromatic high-energy X-ray diffraction setup was used to investigate the synthesis of MOFs using cation-impregnated polymer resin beads as a ion source. The Co–NDC–DMF (NDC=2,6-naphthalenedicarboxylate; DMF=dimethylformamide) system was investigated, a system which is known to produce at least three distinct frameworks. It was found that the resin-assisted synthesis results in the preferential formation of a topology previously impossible to synthesise in bulk, while the comparable nitrate-salt synthesis appeared to form an alternative phases. It was also found that the resin-assisted synthesis is highly diffusion-controlled. - Graphical abstract: In situ monochromatic high-energy X-ray diffraction study of a MOF synthesis. - Highlights: • Resin-assisted solvothermal MOF synthesis was studied using in situ diffraction. • Full kinetics of reaction can be obtained from in situ data. • Kinetics show that this resin-assisted synthesis is diffusion controlled. • Resin-assisted synthesis enables the production of an alternative bulk phase.

  20. Sintering-resistant Single-Site Nickel Catalyst Supported by Metal-Organic Framework

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhanyong; Schweitzer, Neil; League, Aaron; Bernales Candia, Sandra Varinia; Peters, Aaron; Getsoian, Andrew G.; Wang, Timothy; Miller, Jeffrey T.; Vjunov, Aleksei; Fulton, John L.; Lercher, Johannes A.; Cramer, Christopher J.; Gagliardi, Laura; Hupp, Joseph; Farha, Omar

    2016-02-17

    Developing supported single-site catalysts is an important goal in heterogeneous catalysis, since the well-defined active sites afford opportunities for detailed mechanistic studies, thereby facilitating the design of improved catalysts. We present herein a method for installing Ni ions uniformly and precisely on the node of a Zr-based MOF, NU-1000, in high density and large quantity (denoted as Ni-AIM) using atomic layer deposition (ALD) in a metal–organic framework (MOF) (AIM). Ni-AIM is demonstrated to be an efficient gas-phase hydrogenation catalyst upon activation. The structure of the active sites in Ni-AIM is proposed, revealing its single-site nature. More importantly, due to the organic linker used to construct the MOF support, the Ni ions stay isolated throughout the hydrogenation catalysis, in accord with its long-term stability. A quantum chemical characterization of the catalyst and the catalytic process complements the experimental results. With validation of computational modeling protocols, we further targeted ethylene oligomerization catalysis by Ni-AIM guided by theoretical prediction. Given the generality of the AIM methodology, this emerging class of materials should prove ripe for the discovery of new catalysts for the transformation of volatile substrates.