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Sample records for raney nickel catalysts

  1. Polymer-Supported Raney Nickel Catalysts for Sustainable Reduction Reactions

    Directory of Open Access Journals (Sweden)

    Haibin Jiang

    2016-06-01

    Full Text Available Green is the future of chemistry. Catalysts with high selectivity are the key to green chemistry. Polymer-supported Raney catalysts have been found to have outstanding performance in the clean preparation of some chemicals. For example, a polyamide 6-supported Raney nickel catalyst provided a 100.0% conversion of n-butyraldehyde without producing any detectable n-butyl ether, the main byproduct in industry, and eliminated the two main byproducts (isopropyl ether and methyl-iso-butylcarbinol in the hydrogenation of acetone to isopropanol. Meanwhile, a model for how the polymer support brought about the elimination of byproducts is proposed and confirmed. In this account the preparation and applications of polymer-supported Raney catalysts along with the corresponding models will be reviewed.

  2. Novel methods of stabilization of Raney-Nickel catalyst for fuel-cell electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Al-Saleh, M.A.; Sleem-Ur-Rahman; Kareemuddin, S.M.M.J.; Al-Zakri, A.S. [Dept. of Chemical Engineering, King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)

    1998-04-21

    Two new methods of stabilizing Raney-Nickel (Raney-Ni) catalyst for making fuel-cell anodes were studied. In the first method, the catalyst was oxidized with aqueous H{sub 2}O{sub 2} solution, while in the second, oxygen/air (O{sub 2}/air) was used in a slurry reactor. Effects of different concentrations of H{sub 2}O{sub 2} (5-25 wt.%) and different pressures (10-20 psig) of gas were investigated. The stabilized catalyst was characterized using BET surface area, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The catalyst was used in fuel-cell anodes and the electrochemical performance was determined in an alkaline half-cell. The results were compared with electrodes prepared using conventionally stabilized catalysts. The hydrogen peroxide-treated catalyst has higher BET surface area and produces electrodes with lower polarization. In addition to this, H{sub 2}O{sub 2} treatment is convenient, fast and needs simple equipment which involves no instrumentation. Use of oxygen in a slurry reactor to stabilize the catalyst is also convenient but electrode performance is relatively poor. (orig.)

  3. TOTAL HYDROGENATION OF BIOMASS-DERIVED FURFURAL OVER RANEY NICKEL-CLAY NANOCOMPOSITE CATALYSTS

    Directory of Open Access Journals (Sweden)

    Rodiansono Rodiansono

    2013-08-01

    Full Text Available Inexpensive Raney Ni-clay composite (R-Ni/clay catalysts exhibited excellent activity and reusability in the total hydrogenation of biomass-derived furfural into tetrahydrofurfuryl alcohol under mild conditions. For the Raney Ni-bentonite (R-Ni/BNT catalysts, the complete reaction was achieved at 393 K, 180 min giving almost 99% yield of tetrahydrofurfuryl alcohol. The R-Ni/BNT catalyst was found to be reusable without any significant loss of activity and selectivity for at least six consecutive runs.

  4. Influence of RANEY Nickel on the Formation of Intermediates in the Degradation of Lignin

    Directory of Open Access Journals (Sweden)

    Daniel Forchheim

    2012-01-01

    Full Text Available Lignin forms an important part of lignocellulosic biomass and is an abundantly available residue. It is a potential renewable source of phenol. Liquefaction of enzymatic hydrolysis lignin as well as catalytical hydrodeoxygenation of the main intermediates in the degradation of lignin, that is, catechol and guaiacol, was studied. The cleavage of the ether bonds, which are abundant in the molecular structure of lignin, can be realised in near-critical water (573 to 673 K, 20 to 30 MPa. Hydrothermal treatment in this context provides high selectivity in respect to hydroxybenzenes, especially catechol. RANEY Nickel was found to be an adequate catalyst for hydrodeoxygenation. Although it does not influence the cleavage of ether bonds, RANEY Nickel favours the production of phenol from both lignin and catechol. The main product from hydrodeoxygenation of guaiacol with RANEY Nickel was cyclohexanol. Reaction mechanism and kinetics of the degradation of guaiacol were explored.

  5. Methane decomposition on Fe-Cu Raney-type catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, A.F.; Orfao, J.J.M.; Figueiredo, J.L. [Laboratorio de Catalise e Materiais, Laboratorio Associado LSRE/LCM, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)

    2009-10-15

    The decomposition of methane into hydrogen and carbon was studied on Fe-Cu catalysts of Raney-type. The activity of the catalysts was assessed by comparing the experimental conversions with the calculated equilibrium conversions for each set of experimental conditions. The stability of the catalysts was assessed by comparing the maximum conversions with the conversions at the end of 5-hour tests. The carbon deposits obtained consist mostly of carbon nanofibers. Good results were obtained when the Fe-Cu Raney-type systems were thermally treated in situ at 600 C, as a result of incipient alloy formation. These catalysts showed higher stability than the monometallic Raney-Fe catalysts. (author)

  6. Hydrogen production via methane decomposition on Raney-type catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, J.L.; Orfao, J.J.M.; Cunha, A.F. [Laboratorio de Catalise e Materiais, Laboratorio Associado LSRE/LCM, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)

    2010-09-15

    The catalytic decomposition of methane into hydrogen and carbon was studied on La{sub 2}O{sub 3} doped Ni and Ni-Cu Raney-type catalysts. The activity and stability of the catalysts were assessed by comparing the experimental conversions with the calculated equilibrium conversions for each set of experimental conditions, and the maximum conversions with the conversions at the end of (at least) 5 h tests, respectively. Improved stability of La{sub 2}O{sub 3} doped catalysts was ascribed to an electronic promotion effect. There is an optimum load of the promoter, which provides for extended periods of stable catalyst operation. The carbon deposits consist of carbon nanofibers and multiwall carbon nanotubes. The La{sub 2}O{sub 3} doped Ni-Cu Raney-type catalysts presented in this work are remarkably efficient for the production of hydrogen by methane decomposition. (author)

  7. Raney copper catalysts for the water-gas shift reaction - II. Initial catalyst optimisation

    CSIR Research Space (South Africa)

    Mellor, JR

    1997-12-23

    Full Text Available -Zn-A1 catalyst. During the controlled passivation Table 2 Crystalline phase of alloys B, C and D and their product Raney copper catalysts before and after reaction Alloy Precursor alloy phases Cat. phases before reaction a Cat. phases after reaction a... L; dry gas composition=10% CO/90% N2; CO : H20=I : 22.5; catalyst volume=2i0.1 ml): (O)=Cat. A Cu(69.3)Zn(6.9)Al( 19.5); (~)=cat. B Cu(73.6)Zn(10.9)AI(14.8); (W1)=cat. C Cu(72.4)Zn(13.3)Al(12.9); ({))=cat. D Cu(61.5)Zn(15.1)AI(19.1). It can...

  8. Raney-platinum film electrodes for potentially implantable glucose fuel cells. Part 1: Nickel-free glucose oxidation anodes

    Energy Technology Data Exchange (ETDEWEB)

    Kerzenmacher, S.; von Stetten, F. [Laboratory for MEMS Applications, Department of Microsystems Engineering- IMTEK, University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg (Germany); Schroeder, M. [Institut fuer Anorganische und Analytische Chemie, University of Freiburg, Albertstrasse 21, 79104 Freiburg (Germany); Braemer, R. [Hochschule Offenburg- University of Applied Sciences, Badstrasse 24, 79652 Offenburg (Germany); Zengerle, R. [Laboratory for MEMS Applications, Department of Microsystems Engineering- IMTEK, University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg (Germany); Centre for Biological Signalling Studies (bioss), Albert-Ludwigs-Universitaet Freiburg (Germany)

    2010-10-01

    We present a novel fabrication route yielding Raney-platinum film electrodes intended as glucose oxidation anodes for potentially implantable fuel cells. Fabrication roots on thermal alloying of an extractable metal with bulk platinum at 200 C for 48 h. In contrast to earlier works using carcinogenic nickel, we employ zinc as potentially biocompatible alloying partner. Microstructure analysis indicates that after removal of extractable zinc the porous Raney-platinum film (roughness factor {proportional_to}2700) consists predominantly of the Pt{sub 3}Zn phase. Release of zinc during electrode operation can be expected to have no significant effect on physiological normal levels in blood and serum, which promises good biocompatibility. In contrast to previous anodes based on hydrogel-bound catalyst particles the novel anodes exhibit excellent resistance against hydrolytic and oxidative attack. Furthermore, they exhibit significantly lower polarization with up to approximately 100 mV more negative electrode potentials in the current density range relevant for fuel cell operation. The anodes' amenability to surface modification with protective polymers is demonstrated by the exemplary application of an approximately 300 nm thin Nafion coating. This had only a marginal effect on the anode long-term stability and amino acid tolerance. While in physiological glucose solution after approximately 100 h of operation gradually increasing performance degradation occurs, rapid electrode polarization within 24 h is observed in artificial tissue fluid. Optimization approaches may include catalyst enhancement by adatom surface modification and the application of specifically designed protective polymers with controlled charge and mesh size. (author)

  9. The Reduction of Nitriles to Aldehydes: Applications of Raney Nickel ...

    African Journals Online (AJOL)

    NJD

    sive in contact with oxidizers; it is not considered a fire hazard but forms spontaneously flammable phosphine gas when heated. In the absence of a metal catalyst, it has been used under microwave irradiation selectively to reduce the nitro group into an amino group; certain common functional groups including nitrile are ...

  10. Hydrogenolysis of 2-tosyloxy-1,3-propanediol into 1,3-propanediol over Raney Ni catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Zhi, Zheng; Jianli, Wang; Zhen, Lu; Min, Luo; Miao, Zhang; Lixin, Xu; Jianbing [Zhejiang Province Key Laboratory of Biofuel, The State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou (China)

    2013-03-15

    2-Tosyloxy-1,3-propanediol (TPD), a potential precursor for 1,3-propanediol (1,3-PD) production, is produced by the tosylation of glycerol with the help of protecting group techniques. In this work, the hydrogenolysis of TPD into 1,3-PD over Raney Ni catalyst is discussed at different reaction parameters to optimize the reaction conditions for selective formation of 1,3-PD. The mechanisms of the hydrogenolysis of TPD and the side reactions were also confirmed by gas chromatography-mass spectrometry (GC-MS) technique (author)

  11. Hydrogenation of xylose to xylitol on sponge nickel catalyst: a study of the process and catalyst deactivation kinetics

    Directory of Open Access Journals (Sweden)

    Mikkola J.-P.

    2003-01-01

    Full Text Available The kinetics of hydrogenation of xylose to xylitol on a sponge nickel catalyst (commonly referred to as Raney Ni catalyst and of catalyst deactivation were studied. Plausible explanations for the decrease in catalytic activity by means of surface studies, nitrogen adsorption and thermogravimetric analyses of the fresh and spent catalysts are presented. The kinetic parameters of the process were estimated by the use of a semi-competitive model, which allows full competition between the organic species and the hydrogen atoms for the adsorption sites on the catalyst surface (competitive case. In the model, a competitiveness factor (alpha is introduced to take into account that even after complete coverage of the surface by the organic species, interstitial sites remain for the adsorption of the hydrogen atoms.

  12. Sintering of nickel steam reforming catalysts

    DEFF Research Database (Denmark)

    Sehested, Jens; Larsen, Niels Wessel; Falsig, Hanne

    2014-01-01

    . In this paper, particle migration and coalescence in nickel steam reforming catalysts is studied. Density functional theory calculations indicate that Ni-OH dominate nickel transport at nickel surfaces in the presence of steam and hydrogen as Ni-OH has the lowest combined energies of formation and diffusion...

  13. PRODUCTION OF NICKEL CONCENTRATE OF WORKED-OUT METAL-CONTAINING CATALYSTS WITH LOW NICKEL CONTENT

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    O. S. Komarov

    2011-01-01

    Full Text Available The carried out series of experiments confirmed the technical reasonability of enrichment of exhaust nickel catalysts with the purpose of their further usage as nickel concentrates for alloying of casting alloys.

  14. Nickel catalysts for internal reforming in molten carbonate fuel cells

    NARCIS (Netherlands)

    Berger, R.J.; Berger, R.J.; Doesburg, E.B.M.; Doesburg, E.B.M.; van Ommen, J.G.; Ross, J.R.H.; Ross, J.R.H.

    1996-01-01

    Natural gas may be used instead of hydrogen as fuel for the molten carbonate fuel cell (MCFC) by steam reforming the natural gas inside the MCFC, using a nickel catalyst (internal reforming). The severe conditions inside the MCFC, however, require that the catalyst has a very high stability. In

  15. METHANE STEAM REACTION OVER NICKEL CATALYSTS IN THE HYNOL PROCESS

    Science.gov (United States)

    The report discusses the reaction of methane-steam over nickel catalysts in the Hynol process, a process that uses biomass and natural gas as feedstocks to maximize methanol yields and minimize greenhouse gas emissions. EPA's APPCD has established a laboratory in which to conduct...

  16. Nickel nanoparticles: A highly efficient catalyst for one pot synthesis ...

    Indian Academy of Sciences (India)

    Nickel nanoparticles: A highly efficient catalyst for one pot synthesis of tetraketones and biscoumarins. JITENDER M KHURANA. ∗ and KANIKA VIJ. Department of Chemistry, University of Delhi, Delhi 110 007, India e-mail: jmkhurana1@yahoo.co.in. MS received 18 March 2011; revised 17 November 2011; accepted 20 ...

  17. Effect of initial nickel particle size on stability of nickel catalysts for aqueous phase reforming

    NARCIS (Netherlands)

    Haasterecht, Van Tomas; Swart, Marten; Jong, De Krijn P.; Bitter, J.H.

    2016-01-01

    The deactivation behavior by crystallite growth of nickel nanoparticles on various supports (carbon nanofibers, zirconia, SiC, α-Al2O3 and γ-Al2O3) was investigated in the aqueous phase reforming of ethylene glycol. Supported Ni catalysts of ∼10 wt% were prepared by impregnation of carbon nanofibers

  18. Effect of initial nickel particle size on stability of nickel catalysts for aqueous phase reforming

    NARCIS (Netherlands)

    Van Haasterecht, Tomas; Swart, Marten; De Jong, Krijn P.; Bitter, Johannes Hendrik

    The deactivation behavior by crystallite growth of nickel nanoparticles on various supports (carbon nanofibers, zirconia, SiC, α-Al2O3 and γ-Al2O3) was investigated in the aqueous phase reforming of ethylene glycol. Supported Ni catalysts of ∼10 wt% were prepared by impregnation of carbon nanofibers

  19. Mechanism for the Sabatier reaction over a nickel catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Naumov, V.A.; Krylov, O.V.

    1979-10-01

    A mechanism for the Sabatier reaction over a nickel catalyst has been developed for the whole range of hydrogen/carbon dioxide molar ratios, based on the previously derived kinetic equation. The mechanism consists of five reversible elementary reactions, each occurring on a uniform catalyst surface, with no rate-limiting step and involves the formation from gas-phase CO/sub 2/ and adsorbed H/sub 2/ of a surface C(OH)/sub 2/ radical which is consecutively hydrogenated by gas-phase H/sub 2/ to CHOH and CH/sub 2/ surface species and gas-phase methane.

  20. The capacity of modified nickel catalysts derived from discharged catalyst of fertilizer plants for NOx treatment

    Science.gov (United States)

    Ha, T. M. P.; Luong, N. T.; Le, P. N.

    2016-11-01

    In Vietnam for recent years, a large amount of hazardous waste containing nickel (Ni) derived from discharged catalyst of fertilizer plants has caused environmental problems in landfill overloading and the risk of soil or surface water sources pollution. Taking advantage of discharged catalyst, recycling Ni components and then synthesizing new catalysts apply for mono-nitrogen oxides (NOx) treatments is an approach to bring about both economic and environmental benefits. This study was carried out with the main objective: Evaluate the performance of modified catalysts (using recovered Ni from the discharged RKS-2-7H catalyst of Phu My Fertilizer Plant) on NOx treatment. The catalysts was synthesized and modified with active phases consist of recovered Ni and commercial Barium oxide (BaO), Manganese dioxide (MnO2) / Cerium (IV) oxide (CeO2) on the support Aluminium oxide (γ-Al2O3). The results show that the modified catalysts with Ni, Ba, Ce was not more beneficial for NOx removal than which with Ni, Ba, Mn. 98% NOx removal at 350°C with the start temperature at 115°C and the T60 value at 307°C can be obtained with 10Ni10Ba10Mn/Al catalyst.

  1. A nickel iron diselenide-derived efficient oxygen-evolution catalyst

    OpenAIRE

    Xu, Xiang; Song, Fang; Hu, Xile

    2016-01-01

    Efficient oxygen-evolution reaction catalysts are required for the cost-effective generation of solar fuels. Metal selenides have been reported as promising oxygen-evolution catalysts; however, their active forms are yet to be elucidated. Here we show that a representative selenide catalyst, nickel selenide, is entirely converted into nickel hydroxide under oxygen-evolution conditions. This result indicates that metal selenides are unstable during oxygen evolution, and the in situ generated m...

  2. Carbon Monoxide Chemisorption- Characterization and Testing of Prepared Nickel Catalysts for Amination of Ethanol

    OpenAIRE

    Hanafi Setiawan, Achmad

    1994-01-01

    Three types of nickel metal catalyst supported on silica gel have been prepared using impregnation, ion exchanged sodium hydroxide and ion exchanged ammonia methods, in order to investigate the influence of preparation methods on metal dispersion and their activities for amination of ethanol. All the catalyst samples had a nominal nickel loading of 5 % (w/w). After preparation, the catalysts were activated by a drying stage followed by calcination and reduction. The result of transferring the...

  3. Hydrogenation of Levulinic Acid over Nickel Catalysts Supported on Aluminum Oxide to Prepare γ-Valerolactone

    Directory of Open Access Journals (Sweden)

    Jie Fu

    2015-12-01

    Full Text Available Four types of nickel catalysts supported on aluminum oxide (Ni/Al2O3 with different nickel loadings were synthesized using the co-precipitation method and were used for the hydrogenation of levulinic acid (LA to prepare γ-valerolactone (GVL. The synthesized Ni/Al2O3 catalysts exhibited excellent catalytic activity in dioxane, and the activity of the catalysts was excellent even after being used four times in dioxane. The catalytic activity in dioxane as a solvent was found to be superior to the activity in water. Nitrogen physisorption, X-ray diffraction, and transmission electron microscopy were employed to characterize the fresh and used catalysts. The effects of the nickel loading, temperature, hydrogen pressure, and substrate/catalyst ratio on the catalytic activity were investigated.

  4. Gold-TiO{sub 2}-Nickel catalysts for low temperature-driven CO oxidation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hinojosa-Reyes, Mariana, E-mail: kittyhinojosa@hotmail.com [División de Materiales Avanzados, IPICYT, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055 Col. Lomas 4a. sección C.P. 78216, San Luis Potosí, S.L.P., México (Mexico); Zanella, Rodolfo, E-mail: rodolfo.zanella@ccadet.unam.mx [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, A. P. 70-186, Delegación Coyoacán, C.P. 04510, México D. F., México (Mexico); Maturano-Rojas, Viridiana [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, A. P. 70-186, Delegación Coyoacán, C.P. 04510, México D. F., México (Mexico); and others

    2016-04-15

    Graphical abstract: - Highlights: • Nickel-doped TiO{sub 2} catalysts (1 wt. %) drive the CO oxidation at low temperature. • DRIFTS reveals the participation of nickel during the CO oxidation. • Ni(CO){sub 2} bridged species are detected by DRIFTS. • Au/TiO{sub 2}-Ni 1 is the most active and stable catalyst with respect to undoped TiO{sub 2}. • Ti{sup 3+} species corroborate Ni doped TiO{sub 2} and surface oxygen vacancies. - Abstract: Nickel-doped-TiO{sub 2} catalysts were prepared by the sol–gel method and surface modified with gold nanoparticles (AuNPs) by the urea-deposition-precipitation technique. The as-synthesized catalysts were characterized by X-ray diffraction, Raman and XPS spectroscopies, N{sub 2} physisorption, STEM-HAADF microscopy and TPR hydrogen consumption. The Au/TiO{sub 2}-Ni catalysts were evaluated catalytically performing CO oxidation reactions. The catalyst with nickel content of 1 wt. % (Au/TiO{sub 2}-Ni 1) showed the highest CO conversion with respect to the high-nickel-content or bare/commercial TiO{sub 2} at 0 °C. In situ DRIFTS showed a strong participation of both nickel due to the presence of surface-nickel-metallic nanoparticles formed during the CO adsorption process at reaction temperatures above 200 °C, and surface-bridged-nickel-CO species. A minor deactivation rate was observed for the Au/TiO{sub 2}-Ni 1 catalyst in comparison with the Au/TiO{sub 2} one. The oxygen vacancies that were created on the sol–gel-doped TiO{sub 2} improved the catalytic behavior during the performance of CO oxidation reactions, and inhibited the AuNP sintering.

  5. Synthesis of novel platinum-on-flower-like nickel catalysts and their applications in hydrogenation reaction

    Science.gov (United States)

    Zhu, Lihua; Zheng, Tuo; Zheng, Jinbao; Yu, Changlin; Zhou, Qiongyu; Hua, Jingrong; Zhang, Nuowei; Shu, Qing; Chen, Bing H.

    2017-11-01

    Without any capping agent, surfactant or external magnetic field, hierarchical nickel was successfully prepared via a simple hydrothermal reduction method by using hydrazine hydrate as reducing agent. The structure and morphology of the products (for instance, flower-like, column-like and spherical-like) were controlled by adjusting hydrothermal conditions including reaction temperature and solvent. The morphology transformation mechanism was proposed and discussed. Corresponding platinum/nickel catalysts (Pt/Ni) were obtained by the galvanic replacement reaction method. And the catalytic activity of the platinum/nickel samples was evaluated by using selective hydrogenation of nitrobenzene. It was found that platinum/flower-like nickel showed the most excellent catalytic performance among the as-synthesized catalysts in this work, with good stability as well. Moreover, reasons for the enhancement of platinum/flower-like nickel for nitrobenzene hydrogenation were investigated.

  6. Raney Distributions and Random Matrix Theory

    Science.gov (United States)

    Forrester, Peter J.; Liu, Dang-Zheng

    2015-03-01

    Recent works have shown that the family of probability distributions with moments given by the Fuss-Catalan numbers permit a simple parameterized form for their density. We extend this result to the Raney distribution which by definition has its moments given by a generalization of the Fuss-Catalan numbers. Such computations begin with an algebraic equation satisfied by the Stieltjes transform, which we show can be derived from the linear differential equation satisfied by the characteristic polynomial of random matrix realizations of the Raney distribution. For the Fuss-Catalan distribution, an equilibrium problem characterizing the density is identified. The Stieltjes transform for the limiting spectral density of the singular values squared of the matrix product formed from inverse standard Gaussian matrices, and standard Gaussian matrices, is shown to satisfy a variant of the algebraic equation relating to the Raney distribution. Supported on , we show that it too permits a simple functional form upon the introduction of an appropriate choice of parameterization. As an application, the leading asymptotic form of the density as the endpoints of the support are approached is computed, and is shown to have some universal features.

  7. Evaluation of nickel and copper catalysts in biogas reforming for hydrogen production in SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Leonardo Alves; Martins, Andre Rosa; Rangel, Maria do Carmo, E-mail: mcarmov@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Grupo de Estudos em Cinetica e Catalise; Ballarini, Adriana; Maina, Silvia [Instituto de Investigaciones en Catalisis Y Petroquimica Ing. Jose Miguel Parera (INCAPE), Santa Fe (Argentina)

    2017-01-15

    The solid oxide fuel cells (SOFC) enable the efficient generation of clean energy, fitting the current requirements of the growing demand for electricity and for the environment preservation. When powered with biogas (from digesters of municipal wastes), the SOFCs also contribute to reduce the environmental impact of these wastes. The most suitable route to produce hydrogen inside SOFC from biogas is through dry reforming but the catalyst is easily deactivated by coke, because of the high amounts of carbon in the stream. A promising way to overcome this drawback is by adding a second metal to nickel-based catalysts. Aiming to obtain active, selective and stable catalysts for biogas dry reforming, solids based on nickel (15%) and copper (5%) supported on aluminum and magnesium oxide were studied in this work. Samples were prepared by impregnating the support with nickel and copper nitrate, followed by calcination at 500, 600 and 800 deg C. It was noted that all solids were made of nickel oxide, nickel aluminate and magnesium aluminate but no copper compound was found. The specific surface areas did not changed with calcination temperature but the nickel oxide average particles size increased. The solids reducibility decreased with increasing temperature. All catalysts were active in methane dry reforming, leading to similar conversions but different selectivities to hydrogen and different activities in water gas shift reaction (WGSR). This behavior was assigned to different interactions between nickel and copper, at different calcination temperatures. All catalysts were active in WGSR, decreasing the hydrogen to carbon monoxide molar ratio and producing water. The catalyst calcined at 500 deg C was the most promising one, leading to the highest hydrogen yield, besides the advantage of being produced at the lowest calcination temperature, requiring less energy in its preparation. (author)

  8. CO{sub x}-free hydrogen and carbon nanofibers production by methane decomposition over nickel-alumina catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, Nima; Rezaei, Mehran; Meshkani, Fereshteh [Faculty of Engineering, University of Kashan, Kashan (Iran, Islamic Republic of)

    2016-02-15

    Nickel catalysts supported on mesoporous nanocrystalline gamma alumina with various nickel loadings were prepared and employed for thermocatalytic decomposition of methane into CO{sub x}-free hydrogen and carbon nanofibers. The prepared catalysts with different nickel contents exhibited mesoporous structure with high surface area in the range of 121.3 to 66.2m{sup 2}g{sup -1}. Increasing in nickel content decreased the pore volume and increased the crystallite size. The catalytic results revealed that the nickel content and operating temperature both play important roles on the catalytic performance of the prepared catalysts. The results showed that increasing in reaction temperature increased the initial conversion of catalysts and significantly decreased the catalyst lifetime. Scanning electron microscopy (SEM) analysis of the spent catalysts evaluated at different temperatures revealed the formation of intertwined carbon filaments. The results showed that increasing in reaction temperature decreased the diameters of nanofibers and increased the formation of encapsulating carbon.

  9. Nitrogen-Doped Carbon Encapsulated Nickel/Cobalt Nanoparticle Catalysts for Olefin Migration of Allylarenes

    DEFF Research Database (Denmark)

    Kramer, Søren; Mielby, Jerrik Jørgen; Buss, Kasper Spanggård

    2017-01-01

    Olefin migration of allylarenes is typically performed with precious metal-based homogeneous catalysts. In contrast, very limited progress has been made using cheap, earth-abundant base metals as heterogeneous catalysts for these transformations - in spite of the obvious economic and environmental...... advantages. Herein, we report on the use of an easily prepared heterogeneous catalyst material for the migration of olefins, in particular allylarenes. The catalyst material consists of nickel/cobalt alloy nanoparticles encapsulated in nitrogen-doped carbon shells. The encapsulated nanoparticles are stable...

  10. Perlite as a potential support for nickel catalyst in the process of sunflower oil hydrogenation

    Science.gov (United States)

    Radonjić, V.; Krstić, J.; Lončarević, D.; Jovanović, D.; Vukelić, N.; Stanković, M.; Nikolova, D.; Gabrovska, M.

    2015-12-01

    Investigation was conducted in order to elucidate the possibility of using perlite as support for preparation of nickel based precursor catalyst, potentially applicable in vegetable oil hydrogenation process. On three differently prepared expanded perlite, nickel catalyst precursors with identical Ni/SiO2 = 1.1 and Ni/Mg = 10/1 ratios were synthesized by precipitation-deposition method. Different techniques, SEM micrography, He-pycnometry, calcimetry, Hg-porosimetry, N2-physisorption, H2-chemisorption and temperature programmed reduction, were used for characterization of obtained samples. Determining the precursor texture, morphology and reducibility shows a successfully deposited nickel phase on perlite support with promising properties for vegetable oil hydrogenation. Chosen precursor was reduced and passivated in paraffin oil and the obtained catalyst showed significant catalytic activity in the test of sunflower oil hydrogenation.

  11. Why does the Conductivity of a Nickel Catalyst Increase during Sulfidation? An Exemplary Study Using an In Operando Sensor Device

    Directory of Open Access Journals (Sweden)

    Peter Fremerey

    2015-10-01

    Full Text Available In order to study the sulfidation of a catalyst fixed bed, an in operando single pellet sensor was designed. A catalyst pellet from the fixed bed was electrically contacted and its electrical response was correlated with the catalyst behavior. For the sulfidation tests, a nickel catalyst was used and was sulfidized with H2S. This catalyst had a very low conductivity in the reduced state. During sulfidation, the conductivity of the catalyst increased by decades. A reaction from nickel to nickel sulfide occurred. This conductivity increase by decades during sulfidation had not been expected since both nickel and nickel sulfides behave metallic. Only by assuming a percolation phenomenon that originates from a volume increase of the nickel contacts when reacting to nickel sulfides, this effect can be explained. This assumption was supported by sulfidation tests with differently nickel loaded catalysts and it was quantitatively estimated by a general effective media theory. The single pellet sensor device for in operando investigation of sulfidation can be considered as a valuable tool to get further insights into catalysts under reaction conditions.

  12. Why does the Conductivity of a Nickel Catalyst Increase during Sulfidation? An Exemplary Study Using an In Operando Sensor Device.

    Science.gov (United States)

    Fremerey, Peter; Jess, Andreas; Moos, Ralf

    2015-10-23

    In order to study the sulfidation of a catalyst fixed bed, an in operando single pellet sensor was designed. A catalyst pellet from the fixed bed was electrically contacted and its electrical response was correlated with the catalyst behavior. For the sulfidation tests, a nickel catalyst was used and was sulfidized with H₂S. This catalyst had a very low conductivity in the reduced state. During sulfidation, the conductivity of the catalyst increased by decades. A reaction from nickel to nickel sulfide occurred. This conductivity increase by decades during sulfidation had not been expected since both nickel and nickel sulfides behave metallic. Only by assuming a percolation phenomenon that originates from a volume increase of the nickel contacts when reacting to nickel sulfides, this effect can be explained. This assumption was supported by sulfidation tests with differently nickel loaded catalysts and it was quantitatively estimated by a general effective media theory. The single pellet sensor device for in operando investigation of sulfidation can be considered as a valuable tool to get further insights into catalysts under reaction conditions.

  13. Potassium/calcium/nickel oxide catalysts for the oxidative coupling of methane

    NARCIS (Netherlands)

    Dooley, K.; Dooley, Kerry M.; Ross, J.R.H.; Ross, Julian R.H.

    1992-01-01

    A series of potassium/calcium/nickel oxides were tested for the oxidative coupling of methane (OCM) at 843–943 K and water addition to the feed at 0–66 mol-%. The K/Ni ratios varied from 0.0–0.6 and Ca/Ni from 0.0–11; catalysts with no nickel were also tested. At least 10% water in the feed and

  14. Electroless Nickel-Based Catalyst for Diffusion Limited Hydrogen Generation through Hydrolysis of Borohydride

    Directory of Open Access Journals (Sweden)

    Shannon P. Anderson

    2013-07-01

    Full Text Available Catalysts based on electroless nickel and bi-metallic nickel-molybdenum nanoparticles were synthesized for the hydrolysis of sodium borohydride for hydrogen generation. The catalysts were synthesized by polymer-stabilized Pd nanoparticle-catalyzation and activation of Al2O3 substrate and electroless Ni or Ni-Mo plating of the substrate for selected time lengths. Catalytic activity of the synthesized catalysts was tested for the hydrolyzation of alkaline-stabilized NaBH4 solution for hydrogen generation. The effects of electroless plating time lengths, temperature and NaBH4 concentration on hydrogen generation rates were analyzed and discussed. Compositional analysis and surface morphology were carried out for nano-metallized Al2O3 using Scanning Electron Micrographs (SEM and Energy Dispersive X-Ray Microanalysis (EDAX. The as-plated polymer-stabilized electroless nickel catalyst plated for 10 min and unstirred in the hydrolysis reaction exhibited appreciable catalytic activity for hydrolysis of NaBH4. For a zero-order reaction assumption, activation energy of hydrogen generation using the catalyst was estimated at 104.6 kJ/mol. Suggestions are provided for further work needed prior to using the catalyst for portable hydrogen generation from aqueous alkaline-stabilized NaBH4 solution for fuel cells.

  15. How NO affects nickel and cobalt nitrates at low temperatures to arrive at highly dispersed silica-supported nickel and cobalt catalysts

    NARCIS (Netherlands)

    Wolters, M.|info:eu-repo/dai/nl/304829560; Munnik, P.|info:eu-repo/dai/nl/328228524; Bitter, J.H.|info:eu-repo/dai/nl/160581435; de Jongh, P.E.|info:eu-repo/dai/nl/186125372; de Jong, K.P.|info:eu-repo/dai/nl/06885580X

    2011-01-01

    Impregnation of porous silica supports with cobalt and nickel nitrate precursor solutions is a convenient method to prepare supported nickel and cobalt (oxide) catalysts. However, the metal (oxide) dispersion obtained is highly dependent on the gas atmosphere during thermal treatment to convert the

  16. Processing of spent nickel catalyst for fat recovery

    Directory of Open Access Journals (Sweden)

    Ibrahim Nasir, Mohammad

    2002-06-01

    Full Text Available Spent nickel catalyst (SNC have the potential of insulting the quality of the environment in a number of ways. The disposal of SNC will have a pollution effect. Optimum recovery of fat from SNC , could save the environment and reduce the oil loss. Hexane has been the solvent of choice for oil extraction. Alternative solvents that are considered safer have been evaluated. Hexane, isopropanol, ethanol, and heptane were examined using soxhlet extraction. While hexane was more efficient in oil recovery from SNC, isopropanol proved to be very good, to clarifying separation of oil from waste material and also provide high solvent recovery compared to other solvents. Isopropanol extraction with chill provided separation of miscella into two phases: lower oil–rich and an upper solvent – rich. It saved much energy of vaporization for distilling. An aqueous extraction process with immiscible solvent assisted was tested. Solvent like hexane added to SNC, and water added later with continuous stirring. The mixture was stirred for about 30 minutes, prior to centrifugation. Aqueous process extracted less amount of oil compared to solvent extraction.El catalizador agotado de níquel (SNC tiene el potencial de dañar la calidad del medio ambiente de diversas formas. El depósito de SNC tendrá un efecto de polución. La recuperación óptima de la grasa a partir del SCN, podría conservar el medio ambiente y reducir la pérdida de aceite. El hexano ha sido el disolvente elegido para la extracción del aceite. También se han evaluado disolventes alternativos que son considerados seguros. Se han examinado hexano, isopropanol, etanol y heptano usando extracción con soxhlet. Mientras que el hexano fue el mas eficaz en la recuperación del aceite, el isopropanol demostró ser muy bueno para aclarar la separación del aceite a partir de la materia residual y también proporcionó una alta recuperación del disolvente en comparación con los otros

  17. Vapor phase hydrogenation of furfural over nickel mixed metal oxide catalysts derived from layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Sulmonetti, Taylor P.; Pang, Simon H.; Claure, Micaela Taborga; Lee, Sungsik; Cullen, David A.; Agrawal, Pradeep K.; Jones, Christopher W.

    2016-05-01

    The hydrogenation of furfural is investigated over various reduced nickel mixed metal oxides derived from layered double hydroxides (LDHs) containing Ni-Mg-Al and Ni-Co-Al. Upon reduction, relatively large Ni(0) domains develop in the Ni-Mg-Al catalysts, whereas in the Ni-Co-Al catalysts smaller metal particles of Ni(0) and Co(0), potentially as alloys, are formed, as evidenced by XAS, XPS, STEM and EELS. All the reduced Ni catalysts display similar selectivities towards major hydrogenation products (furfuryl alcohol and tetrahydrofurfuryl alcohol), though the side products varied with the catalyst composition. The 1.1Ni-0.8Co-Al catalyst showed the greatest activity per titrated site when compared to the other catalysts, with promising activity compared to related catalysts in the literature. The use of base metal catalysts for hydrogenation of furanic compounds may be a promising alternative to the well-studied precious metal catalysts for making biomass-derived chemicals if catalyst selectivity can be improved in future work by alloying or tuning metal-oxide support interactions.

  18. Nickel removal from nickel-5,10,15,20-tetraphenylporphine using supercritical water in absence of catalyst: a basic study.

    Science.gov (United States)

    Mandal, Pradip Chandra; Wahyudiono; Sasaki, Mitsuru; Goto, Motonobu

    2011-03-15

    Reactions of nickel-5,10,15,20-tetraphenylporphine (Ni-TPP) were studied in supercritical water in the presence of toluene without the addition of any catalyst, H(2) or H(2)S that is called a green process. The objective of this study was to remove nickel from Ni-TPP, the most common metal compound present in heavy crude, in high extent at low reaction time. All experiments were carried out in an 8.8 mL batch reactor fabricated from hastelloy C-276. The ability of supercritical water (SCW) to remove nickel from Ni-TPP was studied at temperatures of 450-490 °C and water partial pressures of 25-35 MPa. Water partial pressure had no effect on overall conversion at temperatures of 450 °C and a reaction time of 60 min. The overall Ni-TPP conversion was 89.80%, a figure above that of previous catalytic studies. The percentage of nickel removal was estimated as a function of reaction time and temperature. It were temperature 490 °C and pressure 25 MPa at reaction time 90 min where 65.68% nickel were removed by the action of SCW and toluene, as a co-solvent. It was determined that Ni-TPP undergoes a series of reactions, ending in demetallation and ring fragmentation. The obtained results suggest that supercritical water has a capability to remove nickel from Ni-TPP. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Catalytic performance and characterization of cobalt-nickel nano catalysts for CO hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Feyzi, Mostafa; Gholivand, Mohammad Bagher [Razi University, Kermanshah (Iran, Islamic Republic of); Babakhanian, Arash [Islamic Azad University, Kermanshah (Iran, Islamic Republic of)

    2014-01-15

    A series of Co-Ni nano catalysts were prepared by co-precipitation method. We investigated the effect of Co/Ni molar ratios precipitate and calcination conditions on the catalytic performance of cobalt nickel catalysts for Fisher-Tropsch synthesis (FTS). The catalyst containing 90%Co/10%Ni was found to be optimal for the conversion of synthesis gas to light olefins. The activity and selectivity of the optimal catalyst were studied in different operational conditions. The results show that the best operational conditions are the H{sub 2}/CO=2/1 molar feed ratio at 310 .deg. C and GHSV=1,200 h{sup -}1 under 5 bar of pressure. The prepared catalysts were characterized by powder X-ray diffraction (XRD), N{sub 2} adsorption-desorption measurements such as BET and BJH methods, transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA)

  20. Catalytic Fast Pyrolysis of Cellulose by Integrating Dispersed Nickel Catalyst with HZSM-5 Zeolite

    Science.gov (United States)

    Lei, Xiaojuan; Bi, Yadong; Zhou, Wei; Chen, Hui; Hu, Jianli

    2018-01-01

    The effect of integrating dispersed nickel catalyst with HZSM-5 zeolite on upgrading of vapors produced from pyrolysis of lignocellulosic biomass was investigated. The active component nickel nitrate was introduced onto the cellulose substrate by impregnation technique. Based on TGA experimental results, we discovered that nickel nitrate first released crystallization water, and then successively decomposed into nickel oxide which was reduced in-situ to metallic nickel through carbothermal reduction reaction. In-situ generated nickel nanoparticles were found highly dispersed over carbon substrate, which were responsible for catalyzing reforming and cracking of tars. In catalytic fast pyrolysis of cellulose, the addition of nickel nitrate caused more char formation at the expense of the yield of the condensable liquid products. In addition, the selectivity of linear oxygenates was increased whereas the yield of laevoglucose was reduced. Oxygen-containing compounds in pyrolysis vapors were deoxygenated into aromatics using HZSM-5. Moreover, the amount of condensable liquid products was decreased with the addition of HZSM-5.

  1. A Review on Bimetallic Nickel-Based Catalysts for CO2 Reforming of Methane.

    Science.gov (United States)

    Bian, Zhoufeng; Das, Sonali; Wai, Ming Hui; Hongmanorom, Plaifa; Kawi, Sibudjing

    2017-11-17

    In recent years, CO2 reforming of methane (dry reforming of methane, DRM) has become an attractive research area because it converts two major greenhouse gasses into syngas (CO and H2 ), which can be directly used as fuel or feedstock for the chemical industry. Ni-based catalysts have been extensively used for DRM because of its low cost and good activity. A major concern with Ni-based catalysts in DRM is severe carbon deposition leading to catalyst deactivation, and a lot of effort has been put into the design and synthesis of stable Ni catalysts with high carbon resistance. One effective and practical strategy is to introduce a second metal to obtain bimetallic Ni-based catalysts. The synergistic effect between Ni and the second metal has been shown to increase the carbon resistance of the catalyst significantly. In this review, a detailed discussion on the development of bimetallic Ni-based catalysts for DRM including nickel alloyed with noble metals (Pt, Ru, Ir etc.) and transition metals (Co, Fe, Cu) is presented. Special emphasis has been provided on the underlying principles that lead to synergistic effects and enhance catalyst performance. Finally, an outlook is presented for the future development of Ni-based bimetallic catalysts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. CONVERSION OF (±-CITRONELLAL AND ITS DERIVATIVES TO (--MENTHOL USING BIFUNCTIONAL NICKEL ZEOLITE CATALYSTS

    Directory of Open Access Journals (Sweden)

    Indri Badria Adilina

    2015-06-01

    Full Text Available (±-Citronellal and its derivatives were converted to (--menthol by a one-pot reaction system using zeolite based nickel catalysts. The catalysts were prepared by immobilization of nickel on natural zeolite (NZ or synthetic zeolite (ZSM-5 by a simple cation exchange method. Calcination and hydrogen treatment procedures were able to significantly increase the surface area and pore volume of NZ based catalysts whereas negligible changes in the properties were observed for that of ZSM-5. Catalytic reactions were carried out at 70ºC by stirring the mixture in the air for cyclization of (±-citronellal to (±-isopulegol followed by hydrogenation towards the desired (--menthol at 2 Mpa of H2 pressure. The Ni/NZ catalyst was able to convert a (±-citronellal derivative yielding 9% (--menthol (36% selectivity with conversion up to 24%, whereas Ni/ZSM5 catalyst directly converted 65% (±-citronellal to give 4% menthol (6% selectivity. These zeolite based catalysts are therefore potential materials for the conversion of biomass feed stock to value-added chemicals.

  3. Stability and resistance of nickel catalysts for hydrodeoxygenation

    DEFF Research Database (Denmark)

    Mortensen, Peter Mølgaard; Gardini, Diego; de Carvalho, Hudson W. P.

    2014-01-01

    The long term stability and resistance toward carbon deposition, sulfur, chlorine, and potassium of Ni/ZrO2 as a catalyst for the hydrodeoxygenation (HDO) of guaiacol in 1-octanol (as a model compound system for bio-oil) has been investigated at 250 degrees C and 100 bar in a trickle bed reactor...

  4. A C2-symmetric nickel diamine complex as an asymmetric catalyst for enecarbamate additions to butane-2,3-dione.

    Science.gov (United States)

    Fossey, John S; Matsubara, Ryosuke; Vital, Paulo; Kobayashi, Shū

    2005-08-21

    Butane-2,3-dione was activated towards nucleophilic addition of enecarbamates by a series of metal triflate complexes of a C2-symmetric diamine to give stereogenic, aldol-like, t-alcohols, a novel nickel(II) triflate complex was identified as a good catalyst for this asymmetric transformation, and an aquo nickel(II) complex was identified by XRD techniques.

  5. Oxidative methane reforming with an intelligent catalyst: sintering-tolerant supported nickel nanoparticles.

    Science.gov (United States)

    Deng, Jie; Cai, Mengdie; Sun, Wenjing; Liao, Xuemei; Chu, Wei; Zhao, Xiu Song

    2013-11-01

    Smart Catalyst: The cyclical diffusion of nanometer-sized nickel clusters into and out of the perovskite structure under elevated temperature and reducing and oxidizing atmosphere could in situ redeliver and redisperse Ni, thereby reinforcing the anti-coking and -sintering of Ni during oxidative reforming of CH4 . Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Nickel-containing catalysts for methane oxidation to synthesis gas

    Directory of Open Access Journals (Sweden)

    Kusman Dossumov

    2014-12-01

    Full Text Available The partial oxidation of methane to synthesis gas was studied on oxides of metals of variable valence (Mn, La, Cr and Ni, supported on a carrier – ɣ-Al2O3. Among the catalysts studied, the sample of 3% Ni/ɣ-Al2O3 showed the best characteristics by yields of hydrogen and carbon monoxide in the reaction of partial oxidation of methane. The optimal conditions of the process (the reaction temperature of 850 °C, the volume rate of 4500 h-1, and the ratio CH4: O2 = 2:1 cause the increase the concentration of hydrogen and carbon monoxide to 72.2 and 75.3%, respectively. The effect of the heat-treatment temperature and textural characteristics of the Ni/ ɣ-Al2O3 catalyst on its catalytic activity was studied. The NiCe/Al2O3 catalyst developed showed a high stability during 30 hours.

  7. The Effect of Exposed Facets of Ceria to the Nickel Species in Nickel-Ceria Catalysts and Their Performance in a NO + CO Reaction.

    Science.gov (United States)

    Tang, Ke; Liu, Wei; Li, Jing; Guo, Jinxin; Zhang, Jingcai; Wang, Shuping; Niu, Shengli; Yang, Yanzhao

    2015-12-09

    CeO2 rods with {110} facets and cubes with {100} facets were utilized as catalyst supports to probe the effect of crystallographic facets on the nickel species and the structure-dependent catalytic performance. Various analysis methods (ex and in situ XRD, TEM, Raman, XPS, TPR, TPD) were used to investigate the structural forms of the catalysts, and these results indicated that the deposition of nickel species resulted in the formation of two main active types of the catalyst components: NiO strongly or weakly interacted with the surface and Ni-Ce-O solid solution. Notably, the states and distribution ratio of nickel species were related to the shape of CeO2. It was found that CeO2 rods had more active sites to coordinate with nickel species to form a strong interaction with NiO on the surface and a more stable construction when compared to cubes. Furthermore, the nickel-ceria catalysts with rod shape were more active towards NO oxidation with complete conversion below 191 °C, but for cube shape, complete conversion occurred above 229 °C (e.g., for nickel loading of ∼5%, the complete conversion temperature was 154 °C for the rod shape and 229 °C for the cube shape). On the basis of the analysis of the catalysts structure, the superior catalytic activity was due to a combination of surface structures of NiO (mainly strongly interacting with the surface) and nickel ions Ni(2+) in the Ni-Ce-O bulk phase.

  8. Stable hydrogen production from ethanol through steam reforming reaction over nickel-containing smectite-derived catalyst.

    Science.gov (United States)

    Yoshida, Hiroshi; Yamaoka, Ryohei; Arai, Masahiko

    2014-12-25

    Hydrogen production through steam reforming of ethanol was investigated with conventional supported nickel catalysts and a Ni-containing smectite-derived catalyst. The former is initially active, but significant catalyst deactivation occurs during the reaction due to carbon deposition. Side reactions of the decomposition of CO and CH4 are the main reason for the catalyst deactivation, and these reactions can relatively be suppressed by the use of the Ni-containing smectite. The Ni-containing smectite-derived catalyst contains, after H2 reduction, stable and active Ni nanocrystallites, and as a result, it shows a stable and high catalytic performance for the steam reforming of ethanol, producing H2.

  9. Hydrogen production with nickel powder cathode catalysts in microbial electrolysis cells

    KAUST Repository

    Selembo, Priscilla A.

    2010-01-01

    Although platinum is commonly used as catalyst on the cathode in microbial electrolysis cells (MEC), non-precious metal alternatives are needed to reduce costs. Cathodes were constructed using a nickel powder (0.5-1 μm) and their performance was compared to conventional electrodes containing Pt (0.002 μm) in MECs and electrochemical tests. The MEC performance in terms of coulombic efficiency, cathodic, hydrogen and energy recoveries were similar using Ni or Pt cathodes, although the maximum hydrogen production rate (Q) was slightly lower for Ni (Q = 1.2-1.3 m3 H2/m3/d; 0.6 V applied) than Pt (1.6 m3 H2/m3/d). Nickel dissolution was minimized by replacing medium in the reactor under anoxic conditions. The stability of the Ni particles was confirmed by examining the cathodes after 12 MEC cycles using scanning electron microscopy and linear sweep voltammetry. Analysis of the anodic communities in these reactors revealed dominant populations of Geobacter sulfurreduces and Pelobacter propionicus. These results demonstrate that nickel powder can be used as a viable alternative to Pt in MECs, allowing large scale production of cathodes with similar performance to systems that use precious metal catalysts. © 2009 Professor T. Nejat Veziroglu.

  10. Mössbauer Spectroscopy Investigation and Hydrodesulfurization Properties of Iron–nickel Phosphide Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Gaudette, Amy F.; Burns, Autumn W.; Hayes, John R.; Smith, Mica C.; Bowker, Richard H.; Seda, Takele; Bussell, Mark E.

    2010-05-25

    Unsupported and silica-supported FexNi2-xPy catalysts having a range of metal compositions (0 < x 6 2.0) were investigated using Mössbauer spectroscopy, and the results correlated with the surface and hydrodesulfurization (HDS) properties of the supported catalysts. Mössbauer spectroscopy permits determination of the relative site occupancy of Fe atoms in tetrahedral (M(1)) and pyramidal (M(2)) sites in the FexNi2-xPy materials. Fe atoms preferentially occupy M(2) sites for materials with significant Fe contents (x > ~0.60), but the Fe site preference reverses as the Fe content decreases (x < ~0.60). Similar occupation trends are observed for the unsupported and silica-supported FexNi2-xPy materials. Thiophene HDS measurements of the FexNi2-xPy/SiO2 catalysts revealed catalysts with high Fe contents (0.80 6 x 6 2.00) to have low activities, while the activities of Ni-rich catalysts increased dramatically with increased Ni content (0.03 6 x 6 0.60). The highest HDS activity was measured for a catalyst having a nominal precursor composition of Fe0.03Ni1.97P2.00/SiO2; this catalyst was 40% more active than a optimized nickel phosphide catalyst prepared from a precursor having a nominal composition of Ni2.00P1.60/SiO2. The 25 wt.% Fe0.03Ni1.97P2.00/SiO2 catalyst also had a dibenzothiophene HDS activity just over 10% higher than that of the 25 wt.% Ni2.00P1.60/SiO2 catalyst at 548 K. The trend of increasing HDS activity for the FexNi2-xPy/ SiO2 catalysts correlates with preferential Fe occupation of M(1) sites (and, therefore, Ni occupation of M(2) sites). Supported by X-ray photoelectron spectroscopy and oxygen chemisorption measurements, we conclude that the high activity of Ni-rich FexNi2-xPy/SiO2 catalysts can be traced to a high surface density of Ni in M(2) sites that are resistant to site blockage due to S incorporation.

  11. Enhanced sulfur resistance of Ni/SiO2 catalyst for methanation via the plasma decomposition of nickel precursor.

    Science.gov (United States)

    Yan, Xiaoliang; Liu, Yuan; Zhao, Binran; Wang, Yong; Liu, Chang-jun

    2013-08-07

    A Ni/SiO2 catalyst was prepared by the plasma decomposition of a nickel precursor via dielectric barrier discharge (DBD). The obtained Ni/SiO2 catalyst shows an enhanced H2S resistance for methanation of syngas (CO + H2). The plasma decomposition has a significant influence on the structural property of Ni/SiO2. The plasma decomposed catalyst shows less defect sites on Ni particles. The formation of Ni-sulfur species was effectively inhibited. The mechanism of H2S poisoning on different catalysts with and without plasma decomposition was also discussed according to the reaction temperature.

  12. Kinetics of the Sabatier reaction over a nickel catalyst in a flow-circulation system

    Energy Technology Data Exchange (ETDEWEB)

    Naumov, V.A.; Krylov, O.V.

    1979-10-01

    The kinetics of the Sabatier reaction over a nickel catalyst in a flow-circulation system were studied in a continuation of previous experiments conducted in a differential flow reactor, with the same 58.3% Ni/35.7% Cr/sub 2/O/sub 3//5.5% graphite catalyst to derive a total kinetic equation for the reversible process of carbon dioxide hydrogenation to methane and water (the Sabatier reaction). The study was carried out at 200/sup 0/-400/sup 0/C and 1 atm. The reaction rate is a complex function of CO/sub 2/ and H/sub 2/ pressures, but becomes first order in CO/sub 2/ when CO/sub 2/ pressures are much smaller than those of H/sub 2/.

  13. Chemisorption of CO, CO/sub 2/, H/sub 2/ and CH/sub 4/ on methanation catalysts containing nickel and molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Al-Saleh, M.A.; Celiker, H.

    1987-04-01

    Methanation reaction is widely used in industry for gas purification and synthetic methane production as alternate energy source to crude oil. The latter one is a more important and future-promising application area. Methanation of synthesis gas (CO + H/sub 2/) which is produced from coal gasification started gaining considerable attention as a promising clean energy source for the future. Coal which is the starting material for synthetic methane production, is more abundant, dependable and has cheaper prices. The nickel-molybdenum catalyst was found to be a potential candidate for a combined shift and methanation process, because it did not promote carbon deposition using a hydrogen deficient feed gas. The methanation kinetics for the catalysts containing nickel, nickel-molybdenum and molybdenum are reported in terms of turnover rate expressions. It was found that the nickel catalyst has the highest activity, while the molybdenum catalyst has the lowest. The nickel-molybdenum catalyst has more active sites than the nickel catalyst, but is less active in terms of rate per site. Molybdenum by itself has negligible activity. It is observed that the Ni-Mo catalyst has a lower hydrogenation activity than expected based on a physical mixture of metals indicating a chemical interaction between nickel and molybdenum on the support. The activation energies for nickel and Ni-Mo catalysts were reported to be in the range of 20-30 kcal/mole.

  14. Pyrolysis-catalysis of waste plastic using a nickel-stainless-steel mesh catalyst for high-value carbon products.

    Science.gov (United States)

    Zhang, Yeshui; Nahil, Mohamad A; Wu, Chunfei; Williams, Paul T

    2017-11-01

    A stainless-steel mesh loaded with nickel catalyst was produced and used for the pyrolysis-catalysis of waste high-density polyethylene with the aim of producing high-value carbon products, including carbon nanotubes (CNTs). The catalysis temperature and plastic-to-catalyst ratio were investigated to determine the influence on the formation of different types of carbon deposited on the nickel-stainless-steel mesh catalyst. Increasing temperature from 700 to 900°C resulted in an increase in the carbon deposited on the nickel-loaded stainless-steel mesh catalyst from 32.5 to 38.0 wt%. The increase in sample-to-catalyst ratio reduced the amount of carbon deposited on the mesh catalyst in terms of g carbon g -1 plastic. The carbons were found to be largely composed of filamentous carbons, with negligible disordered (amorphous) carbons. Transmission electron microscopy analysis of the filamentous carbons revealed them to be composed of a large proportion (estimated at ∼40%) multi-walled carbon nanotubes (MWCNTs). The optimum process conditions for CNT production, in terms of yield and graphitic nature, determined by Raman spectroscopy, was catalysis temperature of 800°C and plastic-to-catalyst ratio of 1:2, where a mass of 334 mg of filamentous/MWCNTs g -1 plastic was produced.

  15. Recovery of nickel from spent NiO/Al2O3 catalyst through sulfuric acid leaching, precipitation and solvent extraction.

    Science.gov (United States)

    Nazemi, M K; Rashchi, F

    2012-05-01

    Effective recovery of nickel (Ni) from spent NiO/Al(2)O(3) catalyst in a simple hydrometallurgical route is suggested. Nickel recovery of 99.5% was achieved with sulfuric acid leaching. The leach liquor was partly neutralized and nickel ammonium sulfate was precipitated by adding ammonia. The nickel in the supernatant was concentrated by solvent extraction using D2EHPA and subsequently stripped back into sulfuric acid and returned to the precipitation stage. Necessary counter current extraction and stripping stages were determined in McCabe-Thiele diagrams. The suggested method appears simple and very effective in recovering nickel from spent catalysts from the petrochemical industry.

  16. Catalytic Reductions and Tandem Reactions of Nitro Compounds Using in Situ Prepared Nickel Boride Catalyst in Nanocellulose Solution.

    Science.gov (United States)

    Prathap, Kaniraj Jeya; Wu, Qiong; Olsson, Richard T; Dinér, Peter

    2017-09-15

    A mild and efficient method for the in situ reduction of a wide range of nitroarenes and aliphatic nitrocompounds to amines in excellent yields using nickel chloride/sodium borohydride in a solution of TEMPO-oxidized nanocellulose in water (0.01 wt %) is described. The nanocellulose has a stabilizing effect on the catalyst, which increases the turnover number and enables low loading of nickel catalyst (0.1-0.25 mol % NiCl2). In addition, two tandem protocols were developed in which the in situ formed amines were either Boc-protected to carbamates or further reacted with an epoxide to yield β-amino alcohols in excellent yields.

  17. Synthesis of mesoporous zeolite catalysts by in situ formation of carbon template over nickel nanoparticles

    DEFF Research Database (Denmark)

    Abildstrøm, Jacob Oskar; Kegnæs, Marina; Hytoft, Glen

    2016-01-01

    A novel synthesis procedure for the preparation of the hierarchical zeolite materials with MFI structure based on the carbon templating method with in situ generated carbon template is presented in this study. Through chemical vapour deposition of coke on nickel nanoparticles supported on silica ...... and cracking of n-octane is chosen as a model test reaction and the mesoporous zeolite catalyst is found to exhibit higher activity than the conventional catalyst....

  18. Gas-phase hydrogenation/hydrogenolysis of phenol over supported nickel catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Shin, E.J.; Keane, M.A.

    2000-04-01

    The gas-phase hydrogenation/hydrogenolysis of alcoholic solutions of phenol between 423 and 573 K has been studied using a Y zeolite-supported nickel catalyst (2.2% w/w Ni) and Ni/SiO{sub 2} catalysts (1.5--20.3% w/w Ni). This is a viable means of treating concentrated phenol streams to generate recyclable raw material. Phenol hydrogenation proceeded in a stepwise fashion with cyclohexanone as a reactive intermediate while a combination of hydrogenolysis and hydrogenation yielded cyclohexane. Hydrogenolysis to benzene is favored by high nickel loadings and elevated temperatures. A catalytic hydrogen treatment of cyclohexanone and cyclohexanol helped to establish the overall reaction network/mechanism. The possible role of thermodynamic limitations is considered and structure sensitivity is addressed; reaction data are subjected to a pseudo-first-order kinetic treatment. Hydrogen temperature-programmed desorption (H{sub 2}-TPD) has revealed the existence of different forms of surface hydrogen. Selectivity is interpreted on the basis of the H{sub 2}-TPD profiles and the possible phenol/catalyst interactions. The zeolite sample only catalyzed (via the surface Bronsted acidity) anisole formation in the presence of methanol, but this was suppressed when hexanol was used; the zeolite then promoted hydrogenolysis. The zeolite, however, deactivated and this was not reversed by heating in hydrogen. The results of the hydrogen treatment of aqueous rather than alcoholic phenol solutions are presented, where a switch from methanol to water was accompanied by a move from highly selective hydrogenolysis to highly selective hydrogenation.

  19. Steam reforming of liquid hydrocarbons over a nickel-alumina spinel catalyst

    Science.gov (United States)

    Fauteux-Lefebvre, Clémence; Abatzoglou, Nicolas; Blanchard, Jasmin; Gitzhofer, François

    Interest in steam reforming of liquid hydrocarbons is growing due to the necessity of developing reliable alternatives for their use in fuel cells. In particular, solid oxide fuel cells, which can operate with mixtures of H 2 and CO, are excellent candidates for being fed with liquid fuels coming from both fossil and renewable sources. Fossil-derived, synthetic diesel is an interesting option. In this work, an Al 2O 3-ZrO 2-supported nickel-alumina spinel was tested in a lab-scale isothermal packed-bed reactor as a catalyst of steam reforming of propane, hexadecane and tetralin as surrogates of constitutive families of all commercially available diesel fuels. The results show that the reaction reaches equilibrium at reaction severities lower than those reported in the literature. When operated at steam excess of 250%, carbon formation is not higher than expected by theoretical thermodynamic equilibrium calculations, and no significant catalyst deactivation is observed over the test durations. Scanning electron microscopy of the fresh and used catalyst surfaces shows no significant quantities of carbon.

  20. Sulfur Tolerant Magnesium Nickel Silicate Catalyst for Reforming of Biomass Gasification Products to Syngas

    Directory of Open Access Journals (Sweden)

    Scott L. Swartz

    2012-04-01

    Full Text Available Magnesium nickel silicate (MNS has been investigated as a catalyst to convert tars and light hydrocarbons to syngas (CO and H2 by steam reforming and CO2 reforming in the presence of H2S for biomass gasification process at NexTech Materials. It was observed that complete CH4 conversion could be achieved on MNS catalyst granules at 800–900 °C and a space velocity of 24,000 mL/g/h in a simulated biomass gasification stream. Addition of 10–20 ppm H2S to the feed had no apparent impact on CH4 conversion. The MNS-washcoated monolith also showed high activities in converting methane, light hydrocarbons and tar to syngas. A 1200 h test without deactivation was achieved on the MNS washcoated monolith in the presence of H2S and/or NH3, two common impurities in gasified biomass. The results indicate that the MNS material is a promising catalyst for removal of tar and light hydrocarbons from biomass gasified gases, enabling efficient use of biomass to produce power, liquid fuels and valuable chemicals.

  1. Nickel and cobalt as active phase on supported zirconia catalysts for bio-ethanol reforming: Influence of the reaction mechanism on catalysts performance

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, R.; Rodriguez, L.; Serrano, A.; Munoz, G. [Instituto de Catalisis y Petroleoquimica (CSIC), C/ Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain); Benito, M.; Daza, L. [Instituto de Catalisis y Petroleoquimica (CSIC), C/ Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain); Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Av. Complutense 22, 28040 Madrid (Spain)

    2010-09-15

    Steam reforming of ethanol for hydrogen production was investigated on Co/ZrO{sub 2} and Ni/ZrO{sub 2} catalysts promoted with lanthana. Catalysts were prepared by impregnation method and characterized by XRD and TPR. TPD-R experiments were also carried out to determine the role of active phase on reaction mechanism. The results suggest that adsorbed ethanol is dehydrogenated to acetaldehyde producing hydrogen. Then, the adsorbed acetaldehyde may evolve by different mechanisms, depending on the nature of active phase. On one hand, in cobalt-based catalyst, acetaldehyde could be reformed directly. By acetaldehyde thermal decomposition, methyl and formaldehyde groups are obtained. By coupling of methyl groups, ethane can be obtained. At medium temperature range, WGS reaction contribution is noteworthy. On the other hand, in nickel-based catalyst, acetone was detected in a higher temperature range as the main intermediate reaction product, which indicates that acetaldehyde is transformed into acetone by decarbonylation of acetaldehyde leading to H{sub 2} and CO{sub 2} formation. In addition, acetone can also be reformed to give both H{sub 2} and CO{sub 2}. Contrary to cobalt-based catalyst, ethylene was detected at intermediate range temperature which suggests that it was formed by ethanol dehydration reaction. Ethylene polymerization could easily explain coke formation, which must be avoided. Steam reforming reaction was studied at S/C ratio of 4.84 and 700 C, to verify the activity, selectivity and stability of the catalysts. Ethanol conversion reached 100% and catalysts were very stable for almost 50 h on stream. No significant differences were detected in both catalysts. Nevertheless, TPO experiments performed on used samples demonstrate a higher carbon production on nickel based catalyst that can be correlated to ethanol dehydration contribution on it reaction pathway. (author)

  2. Recovery of Nickel from Reformer Catalysts of Direct Reduction, Using the Pressurized Dissolving Method in Nitric Acid

    Directory of Open Access Journals (Sweden)

    B. Abrar

    2016-10-01

    Full Text Available In the process of direct reduction of iron pellet and production of sponge iron, NiO/Al2O3 act as a catalyst for the generation of carbon monoxide and hydrogen by vapor and natural gas. As an expensive material used in MIDREX method for steel units, this type of catalyst has major environmental problems after accumulation. The steel industry in Iran hopes to employ the MIDREX technique for the 80 percent of the 50 million tons of steel. Thus, the problem of spent catalysts will become a serious environmental challenge. Through the hydrometallurgy method, the present study investigates a possible solution to the problem of catalyst depot (due to heavy metals such as nickel via nickel recovery, which may increase the possibility of selling or re-using the precious and expensive metal. The present research studied the Nickel recovery from spent catalysts of NiO/Al2O¬3 used in reduction gas reliefs of the production of sponge iron unit. In this study, the parameters of temperature, concentration, time and Rpm were studied using pressurized dissolving method. 100% efficiency was achieved at 140 °C for 120 minutes, nitric acid concentration of 1.5 mm, Rpm of 600 and 40 s/l 40 grams per liter.

  3. A new approach for preparation of oil-soluble bimetallic dispersed catalyst from layered ammonium nickel molybdate

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Sang Goo [Climate Change Technology Research Division, Korea Institute of Energy Research, 71-2, Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Na, Jeong-Geol, E-mail: narosu@kier.re.kr [Climate Change Technology Research Division, Korea Institute of Energy Research, 71-2, Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Ko, Chang Hyun [Climate Change Technology Research Division, Korea Institute of Energy Research, 71-2, Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Lee, Ki Bong [Department of Chemical and Biological Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-713 (Korea, Republic of); Rho, Nam Sun [Climate Change Technology Research Division, Korea Institute of Energy Research, 71-2, Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Park, Seung Bin, E-mail: SeungBinPark@kaist.ac.kr [Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2011-04-25

    A new route via the coating of layered ammonium nickel molybdate with oleic acid was developed to prepare an oil-soluble bimetallic dispersed catalyst for the hydrocracking reaction of heavy oil. The layered ammonium nickel molybdate, termed Ni-LTM precursor, was synthesized by precipitation, and the NiMo oleate complex was prepared with the oleic acid serving as an organic ligand. The prepared materials were characterized with X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. It was found that the oleic acid is chemisorbed as a carboxylate onto the Ni-LTM nanoparticles, specifically on Ni-O bond. Also, the catalytic activities were compared between the NiMo oleate complex and other ordinary monometallic dispersed catalysts. The NiMo oleate complex showed excellent catalytic activity, demonstrating its potential to be applied as a novel dispersed catalyst.

  4. OXIDATIVE-REFORMING OF METHANE AND PARTIAL OXIDATION OF METHANE REACTIONS OVER NiO/PrO2/ZrO2 CATALYSTS: EFFECT OF NICKEL CONTENT

    Directory of Open Access Journals (Sweden)

    Y. J. O. Asencios

    Full Text Available Abstract In this work the behavior of NiO-PrO2-ZrO2 catalysts containing various nickel loadings was evaluated in the partial oxidation of methane and oxidative-reforming reactions of methane. The catalysts were characterized by X-Ray Diffraction Analysis (in situ-XRD, Temperature Programmed Reduction (H2-TPR, Scanning Electron Microscopy (SEM/EDX and Adsorption-Desorption of nitrogen (BET area. The reactions were carried out at 750 °C and 1 atm for 5 hours. The catalysts were studied with different nickel content: 0, 5, 10 and 15% (related to total weight of catalyst, wt%. In both reactions, the catalyst containing the mixture of the three oxides (NiO/PrO2/ZrO2 with 15% nickel (15NiPrZr catalyst showed the best activity for the conversion of the reactants into Syngas and showed high selectivity for H2 and CO. The results suggest that the promoter PrO2 and the Niº centers are in a good proportion in the catalyst with 15% Ni. Our results showed that low nickel concentrations in the catalyst led to high metallic dispersion; however, very low nickel concentrations did not favor the methane transformation into Syngas. The catalyst containing only NiO/ZrO2 in the mixture was not sufficient for the catalysis. The presence of the promoter PrO2 was very important for the catalysis of the POM.

  5. Hydrotalcite Catalyst for Hydrocracking Calophyllum inophyllum Oil to Biofuel: A Comparative Study with and without Nickel Impregnation

    Directory of Open Access Journals (Sweden)

    Hafshah Hafshah

    2017-05-01

    Full Text Available This research aims to study the effect of nickel impregnation into hydrotalcite catalyst that use to convert Calophyllum inophyllum oil into biofuel through hydrocracking process. Hydrocracking process was carried out under mild condition (350 °C and 20 bar for two hours in a slurry batch reactor. The adding nickel affected the reaction conversion, yield, and selectivity of gasoil. The process of oxygen removal from the compounds in the oil was characterized by Fourier Transform Infrared Spectroscopy (FTIR, and the compositions of the products were determined by Gas Chromatography-Mass Spectrometry (GC-MS. The results of the study successfully proved that nickel impregnated into hydrotalcite catalyst increased the conversion, yield, and selectivity of gasoil up to 98.57 %, 54.15 %, and 81.31 %, respectively. Copyright © 2017 BCREC Group. All rights reserved Received: 15th November 2016; Revised: 22nd February 2017; Accepted: 22nd February 2017 How to Cite: Hafshah, H., Prajitno, D.H., Roesyadi, A. (2017. Hydrotalcite Catalyst for Hydrocracking Calophyllum inophyllum Oil to Biofuel: A Comparative Study with and without Nickel Impregnation. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2: 273-280 (doi:10.9767/bcrec.12.2.776.273-280 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.776.273-280

  6. Utilization of greenhouse gases through dry reforming: screening of nickel-based bimetallic catalysts and kinetic studies.

    Science.gov (United States)

    Fan, Mun-Sing; Abdullah, Ahmad Zuhairi; Bhatia, Subhash

    2011-11-18

    A series of bimetallic catalysts containing nickel supported over MgO-ZrO2 were tested for activity in the dry reforming of carbon dioxide. A nickel-cobalt bimetallic catalyst gave the best performance in terms of conversion and coke resistance from a range of Ni-X bimetallic catalysts, X=Ca, K, Ba, La, and Ce. The nitrogen-adsorption and hydrogen-chemisorption studies showed the Ni-Co bimetallic supported catalyst to have good surface area with high metal dispersion. This contributed to the high catalytic activity, in terms of conversion activity and stability of the catalyst, at an equimolar methane/carbon dioxide feed ratio. The kinetics of methane dry reforming are studied in a fixed-bed reactor over an Ni-Co bimetallic catalyst in the temperature range 700-800 °C by varying the partial pressures of CH4 and CO2. The experimental data were analyzed based on the proposed reaction mechanism using the Langmuir-Hinshelwood kinetic model. The activation energies for methane and carbon dioxide consumption were estimated at 52.9 and 48.1 kJ mol(-1), respectively. The lower value of CO2 activation energy compared to the activation energy of CH4 indicated a higher reaction rate of CO2, which owes to the strong basicity of nanocrystalline support, MgO-ZrO2.

  7. Nickel Alloy Catalysts for the Anode of a High Temperature PEM Direct Propane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Shadi Vafaeyan

    2014-01-01

    Full Text Available High temperature polymer electrode membrane fuel cells that use hydrocarbon as the fuel have many theoretical advantages over those that use hydrogen. For example, nonprecious metal catalysts can replace platinum. In this work, two of the four propane fuel cell reactions, propane dehydrogenation and water dissociation, were examined using nickel alloy catalysts. The adsorption energies of both propane and water decreased as the Fe content of Ni/Fe alloys increased. In contrast, they both increased as the Cu content of Ni/Cu alloys increased. The activation energy for the dehydrogenation of propane (a nonpolar molecule changed very little, even though the adsorption energy changed substantially as a function of alloy composition. In contrast, the activation energy for dissociation of water (a molecule that can be polarized decreased markedly as the energy of adsorption decreased. The different relationship between activation energy and adsorption energy for propane dehydrogenation and water dissociation alloys was attributed to propane being a nonpolar molecule and water being a molecule that can be polarized.

  8. Photocatalytic water reduction using a polymer coated carbon quantum dot sensitizer and a nickel nanoparticle catalyst

    Science.gov (United States)

    Virca, C. N.; Winter, H. M.; Goforth, A. M.; Mackiewicz, M. R.; McCormick, T. M.

    2017-05-01

    Hydrogen gas is produced photocatalytically using 470 nm light, PVP-coated carbon quantum dots (CQDs) as the photosensitizer, and nickel nanoparticles (NiNPs) as the catalyst. The effect of the amount of polyvinylpyrrolidone (PVP) on the ability of the CQD/NiNP composites to catalyze proton reduction was studied. A maximum of 330 mmols H2/g CQD is produced using 68 μg ml-1 of CQDs and 6 μg ml-1 of NiNPs, with activity persisting for 4 h when 20 wt%-PVP-coated CQDs were used. The H2 production quantum yield under these conditions is 6%. It was found that composites having higher weight percent PVP had decreased rates of H2 production, but increased duration. Increasing the weight percent of PVP coating also increases the fluorescence quantum yield of CQDs. Fluorescence quenching titrations reveal that H2 production could occur by either a reductive or oxidative quenching mechanism. The nanomaterials, prepared using simple methods, are used as the photosensitizer and catalyst in the proton reduction system that operates using visible light.

  9. Increase oil recovery of heavy oil in combustion tube using a new catalyst based nickel ionic solution

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Garnica, M.A.; Hernandez-Perez, J.R.; Cabrera-Reves, M.C.; Schacht-Hernandez, P. [Inst. Mexicano del Petroleo, Mexico City (Mexico); Mamora, D.D. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Texas A and M Univ., College Station, TX (United States)

    2008-10-15

    An ionic liquid-based nickel catalyst was used in conjunction with a combustion tube as an in situ process for heavy oil. The experimental system was comprised of a fluid injection system; a combustion tube; a fluid production system; a gas chromatograph; and a data recording system. Injected nitrogen and air was controlled by a mass flow controller. Nitrogen was used to pressurize the combustion tube and flush the system. Air was injected at a rate of 3 L per minute throughout the combustion run. Liquids leaving the combustion tube passed through a 2-stage separation process. Gases passing through the condenser were kept at low temperatures. Fractions of produced gas were analyzed by the chromatograph. Data loggers were used to obtain data at 30 second intervals. Two combustion experiments were conducted to obtain production times, temperature profiles, and the quality of the oil produced by the catalyst. Combustion tests were conducted with and without the catalyst. An analysis of the experimental data showed that use of the nickel catalyst resulted in increases in oil production as well as higher combustion efficiencies. Use of the catalyst also resulted in a faster combustion front and accelerated oil production. It was concluded that the produced oil contained fewer impurities than oil produced during the control experiment. 23 refs., 3 tabs., 9 figs.

  10. Hydrogen production by auto-thermal reforming of ethanol over nickel catalyst supported on metal oxide-stabilized zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Youn, Min Hye; Seo, Jeong Gil; Song, In Kyu [School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Shinlim-dong, Kwanak-ku, Seoul 151-744 (Korea)

    2010-04-15

    Metal oxide-stabilized mesoporous zirconia supports (M-ZrO{sub 2}) with different metal oxide stabilizer (M = Zr, Y, La, Ca, and Mg) were prepared by a templating sol-gel method. 20 wt% Ni catalysts supported on M-ZrO{sub 2} (M = Zr, Y, La, Ca, and Mg) were then prepared by an incipient wetness impregnation method for use in hydrogen production by auto-thermal reforming of ethanol. The effect of metal oxide stabilizer (M = Zr, Y, La, Ca, and Mg) on the catalytic performance of supported nickel catalysts was investigated. Ni/M-ZrO{sub 2} (M = Y, La, Ca, and Mg) catalysts exhibited a higher catalytic performance than Ni/Zr-ZrO{sub 2}, because surface oxygen vacancy of M-ZrO{sub 2} (M = Y, La, Ca, and Mg) and reducibility of Ni/M-ZrO{sub 2} (M = Y, La, Ca, and Mg) were enhanced by the addition of lower valent metal cation. Hydrogen yield over Ni/M-ZrO{sub 2} (M = Zr, Y, La, Ca, and Mg) catalyst was monotonically increased with increasing both surface oxygen vacancy of M-ZrO{sub 2} support and reducibility of Ni/M-ZrO{sub 2} catalyst. Among the catalysts tested, Ni catalyst supported on yttria-stabilized mesoporous zirconia (Ni/Y-ZrO{sub 2}) showed the best catalytic performance. (author)

  11. Wet chemical synthesis of nickel supported on alumina catalysts; Sintese de catalisadores de niquel suportado em alumina por via umida

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Ranny Rodrigues; Costa, Talita Kenya Oliveira; Morais, Ana Carla da Fonseca Ferreira; Costa, Ana Cristina Figueiredo de Melo; Freitas, Normanda Lino de, E-mail: normanda@ufcg.edu.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

    2016-07-01

    Heterogenic catalysts are those found to be in a different phase on the reaction when compared to the reactants and products. Preferred when compared to homogeneous catalysts due to the easiness on which the separation is processed. The objective of this study is to obtain and characterize Alumina based catalysts impregnated with Nickel (Al{sub 2}O{sub 3}), by wet impregnation. The alumina was synthesized by combustion reaction. Before and after the impregnation the catalysts were characterized by X-ray diffraction (XRD), granulometric analysis, the textural analysis will be held by nitrogen adsorption (BET), energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The results show a presence of a stable crystalline phase of Al2O3 in all the studied samples and after the impregnation the second phase formed was of NiO and NiAl{sub 2}O{sub 4}. The Al{sub 2}O{sub 3} e Ni/Al{sub 2}O{sub 3} catalysts resulted in clusters with a medium diameter of 18.9 and 14.2 μm, respectively. The catalysts show a medium-pore characteristic (medium pore diameter between 2 and 50 nm), the superficial area to Al{sub 2}O{sub 3} and Ni/Al{sub 2}O{sub 3} catalysts were 8.69 m{sup 2}/g and 5.56 m{sup 2}/g, respectively. (author)

  12. Design Criteria, Operating Conditions, and Nickel-Iron Hydroxide Catalyst Materials for Selective Seawater Electrolysis.

    Science.gov (United States)

    Dionigi, Fabio; Reier, Tobias; Pawolek, Zarina; Gliech, Manuel; Strasser, Peter

    2016-05-10

    Seawater is an abundant water resource on our planet and its direct electrolysis has the advantage that it would not compete with activities demanding fresh water. Oxygen selectivity is challenging when performing seawater electrolysis owing to competing chloride oxidation reactions. In this work we propose a design criterion based on thermodynamic and kinetic considerations that identifies alkaline conditions as preferable to obtain high selectivity for the oxygen evolution reaction. The criterion states that catalysts sustaining the desired operating current with an overpotential <480 mV in alkaline pH possess the best chance to achieve 100 % oxygen/hydrogen selectivity. NiFe layered double hydroxide is shown to satisfy this criterion at pH 13 in seawater-mimicking electrolyte. The catalyst was synthesized by a solvothermal method and the activity, surface redox chemistry, and stability were tested electrochemically in alkaline and near-neutral conditions (borate buffer at pH 9.2) and under both fresh seawater conditions. The Tafel slope at low current densities is not influenced by pH or presence of chloride. On the other hand, the addition of chloride ions has an influence in the temporal evolution of the nickel reduction peak and on both the activity and stability at high current densities at pH 9.2. Faradaic efficiency close to 100 % under the operating conditions predicted by our design criteria was proven using in situ electrochemical mass spectrometry. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Kinetics of the Sabatier reaction over a nickel catalyst in a flow system

    Energy Technology Data Exchange (ETDEWEB)

    Naumov, V.A.; Krylov, O.V.; Gavrilov, L.I.

    1979-07-01

    Methanation of carbon dioxide (the Sabatier reaction) over a 58.3Vertical Bar3< Ni/35.7Vertical Bar3< Cr/sub 2/O/sub 3//5.5Vertical Bar3< graphite catalyst was studied in a differential flow reactor at 200/sup 0/-300/sup 0/C, 1 atm, and 0-9:1 H/sub 2//CO/sub 2/ molar ratio (R). Dilution of the reactants with methane or steam, the reaction products, which were not adsorbed on nickel under the reaction conditions, did not inhibit the reaction. Analysis of an empirical kinetic equation showed that the reaction rate was a nonlinear function of R and passed through a temperature-dependent maximum at R = 0.0386 (72.1Vertical Bar3< CO/sub 2/ in the feed) at 250/sup 0/C and at R = 0.575 (63.5Vertical Bar3< CO/sub 2/) at 300/sup 0/C, which was in good agreement with experiment.

  14. Low-cost removal of organic pollutants with nickel nanoparticle loaded ordered macroporous hydrogel as high performance catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Mingyi, E-mail: tmyi@tjcu.edu.cn [Department of Applied Chemistry, School of Science, Tianjin University of Commerce, Tianjin 300134 (China); Huang, Guanbo, E-mail: gbhuang2007@hotmail.com [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Zhang, Sai [Department of Applied Chemistry, School of Science, Tianjin University of Commerce, Tianjin 300134 (China); Liu, Yue [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Li, Xianxian [Department of Applied Chemistry, School of Science, Tianjin University of Commerce, Tianjin 300134 (China); Wang, Xingrui [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Pang, Xiaobo [Department of Applied Chemistry, School of Science, Tianjin University of Commerce, Tianjin 300134 (China); Qiu, Haixia, E-mail: qhx@tju.edu.cn [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China)

    2014-06-01

    A facile route for the in situ preparation of catalytically active Ni nanoparticles (NPs) in ordered macroporous hydrogel (OMH) has been developed. The hydrogel was fabricated based on polystyrene colloid template. The electronegativity of amide and carboxyl groups on the poly(acrylamide-co-acryl acid) chains of the hydrogel caused strong binding of Ni{sup 2+} ions which made them distribute uniformly inside the hydrogel. When immersed in NaBH{sub 4} aqueous solution, the Ni{sup 2+} ions on the hydrogel were reduced to Ni NPs. The resultant Ni NPs loaded OMH showed good catalytic activity for the reduction of a common organic pollutant, 4-nitrophenol, with NaBH{sub 4}. A kinetic study of the catalytic reaction was carried out. The rate constant per unit weight could reach 0.53 s{sup −1} g{sup −1}, which is much better than many common hydrogel loaded nickel catalysts. Moreover, the current catalyst can be easily separated and recovered with stable catalytic activity. - Highlights: • A new poly(acrylamide-co-acryl acid) hydrogel with ordered macropores. • A simple in situ fabrication of nickel nanoparticles under mild conditions. • High-performance heterogeneous catalyst for removal of nitrophenol from water. • Good recyclability of catalyst without any complicated regeneration process.

  15. TECHNOLOGIES OF DOPING OF CAST IRON THROUGH THE SLAG PHASE WITH USING OF THE SPENT NICKEL- AND COPPER-CONTAINING CATALYSTS

    Directory of Open Access Journals (Sweden)

    I. B. Provorova

    2015-01-01

    Full Text Available We have defined the regularities of the doping of cast iron through the slag phase of nickel and copper due to the waste catalysts using a carbonaceous reducing agent. We have justified the need to use the cast iron chips as a seed in the composition of the slag mixture. We have defined the dependence of the degree of extraction of nickel or copper from spent catalyst on the amount of the catalyst, on the basicity of the slag mixture, on the temperature and time of melting.

  16. Nickel-based xerogel catalysts: Synthesis via fast sol-gel method and application in catalytic hydrogenation of p-nitrophenol to p-aminophenol

    Science.gov (United States)

    Feng, Jin; Wang, Qiang; Fan, Dongliang; Ma, Lirong; Jiang, Deli; Xie, Jimin; Zhu, Jianjun

    2016-09-01

    In order to investigate the roles of three-dimensional network structure and calcium on Ni catalysts, the Ni, Ni-Al2O3, Ni-Ca-Al2O3 xerogel catalysts were successfully synthesized via the fast sol-gel process and chemical reduction method. The crystal structure of three different catalysts was observed with X-ray powder diffraction (XRD). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and nitrogen adsorption-desorption were employed to investigate the role of network structure of xerogel catalysts and the size distribution of Ni nanoparticles. The catalyst composition was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) measurement and energy-dispersive X-ray spectroscopy (EDS). Temperature-programmed reduction (TPR) experiments were carried out to investigate the reducibility of nickel species and the interaction between nickel species and alumina. The catalytic hydrogenation of p-nitrophenol to p-aminophenol was investigated over the prepared nickel-based xerogel catalysts. The conversion of p-nitrophenol was monitored by UV spectrophotometry and high performance liquid chromatography (HPLC). The results show that the catalysts are highly selective for the conversion of p-nitrophenol to p-aminophenol and the order of catalytic activities of the catalysts is Ni < Ni-Al2O3 < Ni-Ca-Al2O3. The catalysts were recycled and were used to evaluate the reutilization.

  17. Adsorption of heavy metal ion from aqueous solution by nickel oxide nano catalyst prepared by different methods

    Directory of Open Access Journals (Sweden)

    Amira M. Mahmoud

    2015-03-01

    Full Text Available Environmental pollution by heavy metal is arising as the most endangering tasks to both water sources and atmosphere quality today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. To limit the spread of the heavy metals within water sources, nickel oxide nanoparticles adsorbents were synthesized and characterized with the aim of removal of one of the aggressive heavy elements, namely; lead ions. Nano nickel oxide adsorbents were prepared using NaOH and oxalic acid dissolved in ethanol as precursors. The results indicated that adsorption capacity of Pb(II ion by NiO-org catalyst is favored than that prepared using NaOH as a precipitant. Nickel oxide nanoparticles prepared by the two methods were characterized structurally and chemically through XRD, DTA, TGA, BET and FT-IR. Affinity and efficiency sorption parameters of the solid nano NiO particles, such as; contact time, initial concentration of lead ions and the dosage of NiO nano catalyst and competitive adsorption behaviors were studied. The results showed that the first-order reaction law fit the reduction of lead ion, also showed good linear relationship with a correlation coefficient (R2 larger than 0.9.

  18. Lindqvist Polyoxoniobate Ion-Assisted Electrodeposition of Cobalt and Nickel Water Oxidation Catalysts.

    Science.gov (United States)

    Liu, YuPing; Guo, Si-Xuan; Ding, Liang; Ohlin, C André; Bond, Alan M; Zhang, Jie

    2015-08-05

    A method has been developed for the efficient electrodeposition of cobalt and nickel nanostructures with the assistance of the Lindqvist ion [Nb6O19](8-). Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry, and a range of electrochemical techniques have been used to characterize the morphology, composition, catalytic water oxidation activity and stability of the films in alkaline solution. SEM images show that films consisting of nanoparticles with diameters of ca. 30 to 40 nm are formed after 40-50 potential cycles of deposition. Nb and Co/Ni are detected in the films by EDX. ICP-MS results show an elemental ratio of 1:1 for Co:Nb and 1:3 for Ni:Nb, respectively. Raman spectra reveal the presence of both [Nb6O19](8-) and Co(OH)2/Ni(OH)2. The films exhibit excellent stability and efficiency for electrocatalytic water oxidation in alkaline solution. Turnover frequencies of 12.9 and 13.2 s(-1) were determined by rotating ring disk electrode voltammetry at an overpotential of 480 mV for Co and Ni films, respectively. Fourier transformed large amplitude alternating current (FTAC) voltammetry reveals an additional underlying oxidation process for Co under catalytic turnover conditions, which indicates that a Co(IV) species is involved in the efficient catalytic water oxidation reactions. FTAC voltammetric data also suggest that the Ni films undergoes a clear phase transformation upon aging in aqueous 1 M NaOH and the electrogenerated higher oxidation state Ni from β-NiOOH is the more active form of the catalyst.

  19. Hydrogen Production by Steam Reforming of Liquefied Natural Gas (LNG) Over Nickel-Phosphorus-Alumina Xerogel Catalyst Prepared by a Carbon-Templating Epoxide-Driven Sol-Gel Method.

    Science.gov (United States)

    Bang, Yongju; Park, Seungwon; Han, Seung Ju; Yoo, Jaekyeong; Choi, Jung Ho; Kang, Tae Hun; Lee, Jinwon; Song, In Kyu

    2016-05-01

    A nickel-phosphorus-alumina xerogel catalyst was prepared by a carbon-templating epoxide-driven sol-gel method (denoted as CNPA catalyst), and it was applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). For comparison, a nickel-phosphorus-alumina xerogel catalyst was also prepared by a similar method in the absence of carbon template (denoted as NPA catalyst). The effect of carbon template addition on the physicochemical properties and catalytic activities of the catalysts in the steam reforming of LNG was investigated. Both CNPA and NPA catalysts showed excellent textural properties with well-developed mesoporous structure. However, CNPA catalyst retained a more reducible nickel aluminate phase than NPA catalyst. XRD analysis of the reduced CNPA and NPA catalysts revealed that nickel sintering on the CNPA catalyst was suppressed compared to that on the NPA catalyst. From H2-TPD and CH4-TPD measurements of the reduced CNPA and NPA catalysts, it was also revealed that CNPA catalyst with large amount of hydrogen uptake and strong hydrogen-binding sites showed larger amount of methane adsorption than NPA catalyst. In the hydrogen production by steam reforming of LNG, CNPA catalyst with large methane adsorption capacity showed a better catalytic activity than NPA catalyst.

  20. Dinuclear and Trinuclear Nickel Complexes as Effective Catalysts for Alternating Copolymerization on Carbon Dioxide and Cyclohexene Oxide.

    Science.gov (United States)

    Tsai, Chen-Yen; Cheng, Fu-Yin; Lu, Kuan-Yeh; Wu, Jung-Tsu; Huang, Bor-Hunn; Chen, Wei-An; Lin, Chu-Chieh; Ko, Bao-Tsan

    2016-08-15

    A series of novel nickel complexes 1-9 supported by NNO-tridentate Schiff-base derivatives have been synthesized and characterized. Treatment of the pro-ligands [L(1)-H = 2,4-di-tert-butyl-6-(((2-(dimethylamino)ethyl)imino)methyl)phenol, L(2)-H = 2-(((2-(dimethylamino)ethyl)imino)methyl)-4,6-bis(2-phenylpropan-2-yl)phenol, L(3)-H = 2-(((2-(dimethylamino)ethyl)imino)methyl)phenol] with Ni(OAc)2·4H2O in refluxing ethanol afforded mono- or bimetallic nickel complexes {[(L(1))Ni(OAc)] (1); (L(2))Ni(OAc)] (2); (L(3))2Ni2(OAc)2(H2O)] (3)}. Alcohol-solvated trimetallic nickel acetate complexes {[(L(3))2Ni3(OAc)4(MeOH)2] (4); (L(3))2Ni3(OAc)4(EtOH)2] (5)} could be generated from the reaction of L(3)-H and anhydrous nickel(II) acetate with a ratio of 2:3 in refluxing anhydrous MeOH or EtOH. The reaction of nickel acetate tetrahydrate and L(4)-H to L(6)-H [L(4)-H = 2-(((2-(dimethylamino)ethyl)imino)methyl)-5-methoxyphenol, L(5)-H = 2-(((2-(dimethylamino)ethyl)imino)methyl)-4-methoxy-phenol, L(6)-H = 2-(((2-(dimethylamino)ethyl)imino)(phenyl)methyl)phenol] produced, respectively, the alcohol-free trinuclear nickel complexes {[(L(4))2Ni3(OAc)4] (7); [(L(5))2Ni3(OAc)4] (8); [(L(6))2Ni3(OAc)4] (9)} with the same ratio in refluxing EtOH under the atmospheric environment. Interestingly, recrystallization of [(L(3))2Ni3(OAc)4(MeOH)] (4) or [(L(3))2Ni3(OAc)4(EtOH)] (5) in the mixed solvent of CH2Cl2/hexane gives [(L(3))2Ni3(OAc)4] (6), which is isostructural with analogues 7-9. All bi- and trimetallic nickel complexes exhibit efficient activity and good selectivity for copolymerization of CO2 with cyclohexene oxide, resulting in copolymers with a high alternating microstructure possessing ≥99% carbonate-linkage content. This is the first example to apply well-defined trinuclear nickel complexes as efficient catalysts for the production of perfectly alternating poly(cyclohexene carbonate).

  1. Conversion of Methane into Methanol and Ethanol over Nickel Oxide on Ceria-Zirconia Catalysts in a Single Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Okolie, Chukwuemeka [School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW Atlanta GA 30332 USA; Belhseine, Yasmeen F. [School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW Atlanta GA 30332 USA; Lyu, Yimeng [School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW Atlanta GA 30332 USA; Yung, Matthew M. [National Renewable Energy Laboratory, Golden CO 80401 USA; Engelhard, Mark H. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Lab, Richland WA 99354 USA; Kovarik, Libor [Environmental Molecular Sciences Laboratory, Pacific Northwest National Lab, Richland WA 99354 USA; Stavitski, Eli [National Synchrotron Light Source II, Brookhaven National Laboratory, Upton NY 11973 USA; Sievers, Carsten [School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW Atlanta GA 30332 USA

    2017-09-26

    Direct conversion of methane into alcohols is a promising technology for converting stranded methane reserves into liquids that can be transported in pipelines and upgraded to value-added chemicals. We demonstrate that a catalyst consisting of small nickel oxide clusters supported on ceria-zirconia (NiO/CZ) can selectively oxidize methane to methanol and ethanol in a single, steady-state process at 723 K using O2 as an abundantly available oxidant. The presence of steam is required to obtain alcohols rather than CO2 as the product of catalytic combustion. The unusual activity of this catalyst is attributed to the synergy between the small Lewis acidic NiO clusters and the redox-active CZ support, which also stabilizes the small NiO clusters.

  2. Conversion of Methane into Methanol and Ethanol over Nickel Oxide on Ceria-Zirconia Catalysts in a Single Reactor.

    Science.gov (United States)

    Okolie, Chukwuemeka; Belhseine, Yasmeen F; Lyu, Yimeng; Yung, Matthew M; Engelhard, Mark H; Kovarik, Libor; Stavitski, Eli; Sievers, Carsten

    2017-10-23

    The conversion of methane into alcohols under moderate reaction conditions is a promising technology for converting stranded methane reserves into liquids that can be transported in pipelines and upgraded to value-added chemicals. We demonstrate that a catalyst consisting of small nickel oxide clusters supported on ceria-zirconia (NiO/CZ) can convert methane to methanol and ethanol in a single, steady-state process at 723 K using O2 as an abundantly available oxidant. The presence of steam is required to obtain alcohols rather than CO2 as the product of catalytic combustion. The unusual activity of this catalyst is attributed to the synergy between the small Lewis acidic NiO clusters and the redox-active CZ support, which also stabilizes the small NiO clusters. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Raney-platinum film electrodes for potentially implantable glucose fuel cells. Part 2: Glucose-tolerant oxygen reduction cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Kerzenmacher, S.; Kraeling, U.; von Stetten, F. [Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg (Germany); Schroeder, M. [Institut fuer Anorganische und Analytische Chemie, University of Freiburg, Albertstrasse 21, 79104 Freiburg (Germany); Braemer, R. [Hochschule Offenburg - University of Applied Sciences, Badstrasse 24, 79652 Offenburg (Germany); Zengerle, R. [Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg (Germany); Centre for Biological Signalling Studies (bioss), Albert-Ludwigs-Universitaet Freiburg (Germany)

    2010-10-01

    We report the fabrication and characterization of glucose-tolerant Raney-platinum cathodes for oxygen reduction in potentially implantable glucose fuel. Fabricated by extraction of aluminum from 1 {mu}m thin platinum-aluminum bi-layers annealed at 300 C, the novel cathodes show excellent resistance against hydrolytic and oxidative attack. This renders them superior over previous cathodes fabricated from hydrogel-bound catalyst particles. Annealing times of 60, 120, and 240 min result in approximately 400-550 nm thin porous films (roughness factors {proportional_to}100-150), which contain platinum and aluminum in a ratio of {proportional_to}9:1. Aluminum release during electrode operation can be expected to have no significant effect on physiological normal levels, which promises good biocompatibility. Annealing time has a distinct influence on the density of trenches formed in the cathode. Higher trench densities lead to lower electrode potentials in the presence of glucose. This suggests that glucose sensitivity is governed by mixed potential formation resulting from oxygen depletion within the trenches. During performance characterization the diffusion resistance to be expected from tissue capsule formation upon electrode implantation was taken into account by placing a membrane in front of the cathode. Despite the resulting limited oxygen supply, cathodes prepared by annealing for 60 min show more positive electrode potentials than previous cathodes fabricated from hydrogel-bound activated carbon. Compared to operation in phosphate buffered saline containing 3.0 mM glucose, a potential loss of approximately 120 mV occurs in artificial tissue fluid. This can be reduced to approximately 90 mV with a protective Nafion layer that is easily electro-coated onto the Raney-platinum film. (author)

  4. Synthesis and Catalytic Performances of a Novel Zn-MOF Catalyst Bearing Nickel Chelating Diimine Carboxylate Ligands for Ethylene Oligomerization

    Directory of Open Access Journals (Sweden)

    Suyan Liu

    2015-01-01

    Full Text Available A novel Zn-MOF[Zn3(OH2L2] was synthesized from dicarboxylate ligands with diimine groups (1,4-bis(4-CO2HC6H4-2,3-dimethyl-1,4-diazabutadiene. The physicochemical properties of the material were characterized by a series of technologies including XRD, SEM, and ICP. In order to adapt to the ethylene oligomerization process, a catalyst [Zn3OH2L1Ni2] (denoted as Cat.A possessing active Ni2+ centers was prepared by a postsynthetic treatment method using dichloride nickel as a nickel source in this work. For comparison, α-diimine ligands with/without dicarboxylic acid groups reacted with dichloride nickel to obtain homogenous Cat.B and Cat.C, respectively. The effects of reaction parameters, including n(Al/n(Ni, temperature, and pressure on the oligomerization activities and oligomers distribution were investigated. The results demonstrated that all of catalysts used with diethylaluminum chloride were active for the ethylene oligomerization. Among them, Cat.A and Cat.B showed higher catalytic activities and higher selectivities to low-carbon α-olefins at atmospheric pressure. The Cat.A exhibited the optimal catalytic activity [6.7 × 105 g/(mol·Ni·h·atm] for C4 (91.8% under the conditions of Al/Ni = 1500, P = 1.0 atm, T = 20°C. In addition, Cat.A and Cat.B presented large amount of ethylene polymer, while Cat.C had a higher catalytic activity of ethylene oligomerization at high pressure.

  5. A Membrane-Free Neutral pH Formate Fuel Cell Enabled by a Selective Nickel Sulfide Oxygen Reduction Catalyst.

    Science.gov (United States)

    Yan, Bing; Concannon, Nolan M; Milshtein, Jarrod D; Brushett, Fikile R; Surendranath, Yogesh

    2017-06-19

    Polymer electrolyte membranes employed in contemporary fuel cells severely limit device design and restrict catalyst choice, but are essential for preventing short-circuiting reactions at unselective anode and cathode catalysts. Herein, we report that nickel sulfide Ni 3 S 2 is a highly selective catalyst for the oxygen reduction reaction in the presence of 1.0 m formate. We combine this selective cathode with a carbon-supported palladium (Pd/C) anode to establish a membrane-free, room-temperature formate fuel cell that operates under benign neutral pH conditions. Proof-of-concept cells display open circuit voltages of approximately 0.7 V and peak power values greater than 1 mW cm -2 , significantly outperforming the identical device employing an unselective platinum (Pt) cathode. The work establishes the power of selective catalysis to enable versatile membrane-free fuel cells. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Ni/SiO2 Catalyst Prepared with Nickel Nitrate Precursor for Combination of CO2 Reforming and Partial Oxidation of Methane: Characterization and Deactivation Mechanism Investigation

    Directory of Open Access Journals (Sweden)

    Sufang He

    2015-01-01

    Full Text Available The performance of Ni/SiO2 catalyst in the process of combination of CO2 reforming and partial oxidation of methane to produce syngas was studied. The Ni/SiO2 catalysts were prepared by using incipient wetness impregnation method with nickel nitrate as a precursor and characterized by FT-IR, TG-DTA, UV-Raman, XRD, TEM, and H2-TPR. The metal nickel particles with the average size of 37.5 nm were highly dispersed over the catalyst, while the interaction between nickel particles and SiO2 support is relatively weak. The weak NiO-SiO2 interaction disappeared after repeating oxidation-reduction-oxidation in the fluidized bed reactor at 700°C, which resulted in the sintering of metal nickel particles. As a result, a rapid deactivation of the Ni/SiO2 catalysts was observed in 2.5 h reaction on stream.

  7. Theoretical investigation of the mechanism of tritiated methane dehydrogenation reaction using nickel-based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Liang; Li, Jiamao; Deng, Bing; Yang, Yong; Wang, Heyi [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Li, Weiyi [School of Physics and Chemistry, Xihua University, Chengdu 610065 (China); Li, Shuo, E-mail: lishuo@cqut.edu.cn [School of Chemical Engineering, Chongqing University of Technology, Chongqing 400054 (China); Tan, Zhaoyi, E-mail: tanzhaoyi@caep.cn [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-06-15

    Graphical abstract: - Highlights: • Four-step dehydrogenation of CT{sub 4} catalyzed by Ni to form Ni–C by releasing T{sub 2}. • The process of Ni + CT{sub 4} → NiCT{sub 2} + T{sub 2} is more achievable than that of NiCT{sub 2} → NiC + T{sub 2}. • TNiCT → T{sub 2}NiC step is the RDS with the rate constant of k = 2.8 × 10{sup 13} exp(−313,136/RT). • The hydrogen isotope effect value of k{sub H}/k{sub T} is 2.94, and k{sub D}/k{sub T} is 1.39. • CH{sub 4} and CD{sub 4} dehydrogenations are likely to occur, accompanied by the CT{sub 4} cracking. - Abstract: The mechanism of tritiated methane dehydrogenation reaction catalyzed by nickel-based catalyst was investigated in detail by density functional theory (DFT) at the B3LYP/[6-311++G(d, p), SDD] level. The computational results indicated that the dehydrogenation of tritiated methane is endothermic. The decomposition of tritiated methane catalyzed by Ni to form Ni-based carbon (Ni–C) after a four-step dehydrogenation companied with releasing tritium. After the first and second dehydrogenation steps, Ni + CT{sub 4} formed NiCT{sub 2}. After the third and fourth dehydrogenation steps, NiCT{sub 2} formed NiC. The first and second steps of dehydrogenation occurred on both the singlet and triplet states, and the lowest energy route is Ni + CT{sub 4} → {sup 1}COM → {sup 1}TS1 → {sup 3}IM1 → {sup 3}TS2 → {sup 3}IM2. The third and fourth steps of dehydrogenation occurred on both the singlet and quintet states, and the minimum energy reaction pathway appeared to be IM3 → {sup 1}TS4 → {sup 5}IM4 → {sup 5}TS5 → {sup 5}IM5 → {sup 5}pro + T{sub 2}. The fourth step of dehydrogenation TNiCT → T{sub 2}NiC was the rate-determining step of the entire reaction with the rate constant of k{sub 2} = 2.8 × 10{sup 13} exp(−313,136/RT) (in cm{sup 3} mol{sup −1} s{sup −1}), and its activation energy barrier was calculated to be 51.8 kcal/mol. The Ni-catalyzed CH{sub 4} and CD{sub 4} cracking

  8. Catalyst and its use for the manufacture of methane from gases containing carbon monoxide and dioxide and hydrogen. [preparation of nickel catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Broecker, F.J.; Zirker, G.; Triebskorn, B.; Marosi, L.; Schwarzmann, M.; Dethlefsen, W.; Kaempfer, K.

    1975-10-14

    An improved nickel catalyst from West Germany's BASF AG allows the production of methane from carbon monoxide, carbon dioxide, and hydrogen at a lower feedstock temperature of only 392/sup 0/ to 572/sup 0/F (200/sup 0/ to 300/sup 0/C). The catalyst is manufactured by precipitating the compound Ni/sub 6/Al/sub 2/(OH)/sub 16/CO/sub 3/ x 4H/sub 2/O from aqueous solution, drying it at a temperature of 176/sup 0/ to 356/sup 0/F (80/sup 0/ to 180/sup 0/C), calcining it at a temperature of 572/sup 0/ to 1022/sup 0/F (300/sup 0/ to 550/sup 0/C), and subsequently reducing it in a stream of hydrogen. Between the drying stage and the calcination stage, the temperature is raised at a rate of 3/sup 0/ to 6/sup 0/F (1.66/sup 0/ to 3.33/sup 0/C)/min.

  9. Hydrogen Production by Steam Reforming of Ethanol over Nickel Catalysts Supported on Sol Gel Made Alumina: Influence of Calcination Temperature on Supports.

    Science.gov (United States)

    Yaakob, Zahira; Bshish, Ahmed; Ebshish, Ali; Tasirin, Siti Masrinda; Alhasan, Fatah H

    2013-05-30

    Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/AlS.G.) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel made supports on catalyst activity was tested in ethanol reforming reaction. The characteristics of the sol gel alumina supports and Ni catalysts were affected by the calcination temperature of the supports. The structure of the sol gel made alumina supports was transformed in the order of γ → (γ + θ) → θ-alumina as the calcination temperature of the supports increased from 600 °C to 1000 °C. Both hydrogen yield and ethanol conversion presented a volcano-shaped behavior with maximum values of 4.3 mol/mol ethanol fed and 99.5%, respectively. The optimum values were exhibited over Ni/AlS.G800 (Ni catalyst supported on sol gel made alumina calcined at 800 °C). The high performance of the Ni/AlS.G800 catalyst may be attributed to the strong interaction of Ni species and sol gel made alumina which lead to high nickel dispersion and small particle size.

  10. Surface Reaction Kinetics of Steam- and CO2-Reforming as Well as Oxidation of Methane over Nickel-Based Catalysts

    Directory of Open Access Journals (Sweden)

    Karla Herrera Delgado

    2015-05-01

    Full Text Available An experimental and kinetic modeling study on the Ni-catalyzed conversion of methane under oxidative and reforming conditions is presented. The numerical model is based on a surface reaction mechanism consisting of 52 elementary-step like reactions with 14 surface and six gas-phase species. Reactions for the conversion of methane with oxygen, steam, and CO2 as well as methanation, water-gas shift reaction and carbon formation via Boudouard reaction are included. The mechanism is implemented in a one-dimensional flow field description of a fixed bed reactor. The model is evaluated by comparison of numerical simulations with data derived from isothermal experiments in a flow reactor over a powdered nickel-based catalyst using varying inlet gas compositions and operating temperatures. Furthermore, the influence of hydrogen and water as co-feed on methane dry reforming with CO2 is also investigated.

  11. Bimetallic Nickel/Ruthenium Catalysts Synthesized by Atomic Layer Deposition for Low-Temperature Direct Methanol Solid Oxide Fuel Cells.

    Science.gov (United States)

    Jeong, Heonjae; Kim, Jun Woo; Park, Joonsuk; An, Jihwan; Lee, Tonghun; Prinz, Fritz B; Shim, Joon Hyung

    2016-11-09

    Nickel and ruthenium bimetallic catalysts were heterogeneously synthesized via atomic layer deposition (ALD) for use as the anode of direct methanol solid oxide fuel cells (DMSOFCs) operating in a low-temperature range. The presence of highly dispersed ALD Ru islands over a porous Ni mesh was confirmed, and the Ni/ALD Ru anode microstructure was observed. Fuel cell tests were conducted using Ni-only and Ni/ALD Ru anodes with approximately 350 μm thick gadolinium-doped ceria electrolytes and platinum cathodes. The performance of fuel cells was assessed using pure methanol at operating temperatures of 300-400 °C. Micromorphological changes of the anode after cell operation were investigated, and the content of adsorbed carbon on the anode side of the operated samples was measured. The difference in the maximum power density between samples utilizing Ni/ALD Ru and Pt/ALD Ru, the latter being the best catalyst for direct methanol fuel cells, was observed to be less than 7% at 300 °C and 30% at 350 °C. The improved electrochemical activity of the Ni/ALD Ru anode compared to that of the Ni-only anode, along with the reduction of the number of catalytically active sites due to agglomeration of Ni and carbon formation on the Ni surface as compared to Pt, explains this decent performance.

  12. Carbon-Nanotube-Supported Bio-Inspired Nickel Catalyst and Its Integration in Hybrid Hydrogen/Air Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gentil, Solène [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, CNRS UMR5249, CEA, 38000 Grenoble France; Lalaoui, Noémie [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Dutta, Arnab [Pacific Northwest National Laboratory, Richland WA 99532 USA; Current address: Chemistry Department, IIT Gandhinagar, Gujarat 382355 India; Nedellec, Yannig [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Cosnier, Serge [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Shaw, Wendy J. [Pacific Northwest National Laboratory, Richland WA 99532 USA; Artero, Vincent [Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, CNRS UMR5249, CEA, 38000 Grenoble France; Le Goff, Alan [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France

    2017-01-12

    A biomimetic nickel bis-diphosphine complex incorporating the amino-acid arginine in the outer coordination sphere, was immobilized on modified single-wall carbon nanotubes (SWCNTs) through electrostatic interactions. The sur-face-confined catalyst is characterized by a reversible 2-electron/2-proton redox process at potentials close to the equibrium potential of the H+/H2 couple. Consequently, the functionalized redox nanomaterial exhibits reversible electrocatalytic activity for the H2/2H+ interconversion over a broad range of pH. This system exhibits catalytic bias, analogous to hydrogenases, resulting in high turnover frequencies at low overpotentials for electrocatalytic H2 oxida-tion between pH 0 and 7. This allowed integrating such bio-inspired nanomaterial together with a multicopper oxi-dase at the cathode side in a hybrid bioinspired/enzymatic hydrogen fuel cell. This device delivers ~2 mW cm–2 with an open-circuit voltage of 1.0 V at room temperature and pH 5, which sets a new efficiency record for a bio-related hydrogen fuel cell with base metal catalysts.

  13. Hydrometallurgical route to recover molybdenum, nickel, cobalt and aluminum from spent hydrotreating catalysts in sulphuric acid medium.

    Science.gov (United States)

    Valverde, Ivam Macedo; Paulino, Jéssica Frontino; Afonso, Julio Carlos

    2008-12-30

    This work describes a hydrometallurgical route for processing spent commercial catalysts (CoMo and NiMo/Al2O3), for recovering the active phase and support components. They were initially pre-oxidized (500 degrees C, 5h) in order to eliminate coke and other volatile species present. Pre-oxidized catalysts were dissolved in H2SO4 (9molL-1) at approximately 90 degrees C, and the remaining residues separated from the solution. Molybdenum was recovered by solvent extraction using tertiary amines. Alamine 304 presented the best performance at pH around 1.8. After this step, cobalt (or nickel) was separated by adding aqueous ammonium oxalate in the above pH. Before aluminum recovery, by adding NaOH to the acid solution, phosphorus (H2PO4-) was removed by passing the liquid through a strong anion exchange column. Final wastes occur as neutral and colorless sodium sulphate solutions and the insoluble solid in the acid leachant. The hydrometallurgical route presented in this work generates less final aqueous wastes, as it is not necessary to use alkaline medium during the metal recovery steps. The metals were isolated in very high yields (>98wt.%).

  14. Applications of magnetochemistry to the characterization of calcium-nickel-potassium oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Perry, D.L.; Berdahl, P.H.; Perrino, C. [Lawrence Berkely Laboratory, CA (United States)

    1993-12-31

    Magnetochemical studies, using SQUID magnetometry, have been conducted on calcium-nickel-potassium oxide phases that have been shown to be active in the catalyzed gasification of carbonaceous materials. The research has focused on the chemical state of the paramagnetic nickel(II) oxide system and the paramagnetic oxygen binary compounds with potassium. Studies were performed on various samples of the quaternary metal oxide system that has been synthesized by a variety of routes, including dehydration of hydroxides, thermal decomposition of the parent metal salts (such as nitrates), and the calcining of their parent metal oxides. The magetochemistry is discussed in relationship to the different particles sizes of NiO{sub 3}, the temperature and periods of time of annealing the oxide system, and the synthetic routes used to prepare the compounds. Data are compared to those obtained for the compounds using x-ray photoelectron spectroscopy.

  15. Novel Approach to Tar Removal from Biomass Producer Gas by Means of a Nickel-Based Catalyst

    Science.gov (United States)

    Vosecký, M.; Kameníková, P.; Pohořelý, M.; Skoblja, S.; Punčochář, M.

    The nickel-based catalyst was exposed to the raw gas from gasification of woody biomass with air in a fluidized-bed. After dust removal on a barrier filter and sulphur compounds capture, namely H2S, on an active sorbent made of CuO and ZnO, higher hydrocarbons as tar components were decomposed/reformed on aNi-catalyst. Steam reforming reactions led to decomposition of tar and all hydrocarbons higher than CH4 into mainly H2 and CO which further underwent reaction with steam via the water gas shift reaction to CO2. The reforming reactions caused approximately 10-20 % decrease in the lower heating values of the producer gas from the inlet values 5.0-6.5 MJ m-3. The gas yield increased fromvalues 2.4-2.6 m3 kg-1 to values 2.8-3.0 m3 kg-1 on dry biomass basis. The chosen tar removal concept based on combination of dolomite in the fluidized-bed with the secondary catalytic reactor was proved by 20 hours long experiment in which the finaltar content below 30 mg m-3 was attained corresponding to more than 97 % tar conversion. H2S content in producer gas was expected to be below 100 vol. ppm, bulk of which was captured on the sorbent. Only limited deactivation of thecatalyst by sulphur compounds was found in the front of the catalyst bed where sulphur content was determined as high as 173 wt. ppm compared to 22 wt. ppm in the fresh sample.

  16. HDS, HDN and HDA activities of nickel-molybdenum catalysts supported on alumina

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez-Crespo, M.A. [Instituto Mexicano del Petroleo, Programa de Tratamiento de Crudo Maya. Avenida Eje Central Lazaro Cardenas No.152, Col. San Bartolo Atepehuacan, 07730, Mexico D. F. (Mexico); Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada (CICATA-Altamira, IPN) Km 14.5 Carretera Tampico-puerto Industrial 89600, Altamira, Tamaulipas (Mexico); Torres-Huerta, A.M.; Ramirez-Meneses, E. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada (CICATA-Altamira, IPN) Km 14.5 Carretera Tampico-puerto Industrial 89600, Altamira, Tamaulipas (Mexico); Diaz-Garcia, L. [Instituto Mexicano del Petroleo, Programa de Tratamiento de Crudo Maya. Avenida Eje Central Lazaro Cardenas No.152, Col. San Bartolo Atepehuacan, 07730, Mexico D. F. (Mexico); Arce-Estrada, E.M. [Instituto Politecnico Nacional, Departamento de Metalurgia y Materiales. A.P. 75-876, 07300 Mexico, D. F. (Mexico)

    2008-08-15

    In this work, NiMo-Al{sub 2}O{sub 3} catalysts were prepared by using different alumina precursors. The supports were impregnated by means of the spray at incipient wetness technique in both basic and acid media. Both the supports and fresh catalysts were characterized by the adsorption-desorption isotherms, Temperature-Programmed Reduction (TPR), Thermal Pyridine Adsorption-Desorption (TPD) and X-Ray Diffraction analyses (XRD). After sulfidation, the NiMoS metallic particles were characterized by Transmission Electron Microscopy (TEM). The initial analyses were performed in a trickle-bed reactor by using a real feedstock (Mexican heavy gas oil) and performing hydrotreating reactions (HDS, HDN and HDA) at three different temperatures: 613, 633 and 653 K; and 54 kg cm{sup -} {sup 2}. The catalytic activities are discussed in relation to the physicochemical properties of the NiMo catalysts, alumina phase and pH of the impregnating solution. The catalytic results show an increase in the conversion profiles with temperature. The sulfur conversion was increased from 89 to 99.25%, 91-99%, 90.8-97%, 83-95% and 78-96% when the crystal size of the support varied from 3 to 20 nm, respectively. The nitrogen and aromatic conversions were also increased in the range of 23-45 wt.%. It was found that the {gamma} phase reached a higher catalytic performance than the {eta} phase. The NiMo catalysts synthesized in a basic medium showed a better catalytic performance than that obtained with those prepared in acid solutions. The significance of the kinetic data to compare the catalysts is discussed. The maximum value of the catalytic activity was reached with the catalysts with the smallest particle sizes. (author)

  17. The preparation and properties of lanthanum-promoted nickel-alumina catalysts: Structure of the precipitates

    NARCIS (Netherlands)

    Lippens, Bernhard C.; Fransen, Peter; van Ommen, J.G.; Wijngaarden, Ruud; Bosch, H.; Ross, Julian R.H.

    1985-01-01

    Precursors of La-promoted Ni-alumina catalysts have been prepared by precipitation from their nitrate solutions at pH 7 using solutions of NH4HCO3, Na2CO3 or K2CO3. The preparation was carried out either by coprecipitation from a mixed salt solution or by sequential precipitation of Al3+, La3+ and

  18. Determination of the stability constants for cobalt, nickel and palladium homogeneous catalyst complexes containing triphenylphosphine ligands

    NARCIS (Netherlands)

    Djekic, T.; Zivkovic, Z.; van der Ham, A.G.J.; de Haan, A.B.

    2006-01-01

    Homogeneous catalysts are complex compounds that are always in equilibrium with their free metal, free ligand and other forms of complexes. The ratios between different species are defined by the stability constants, which are influenced by different parameters such as the type of metal, ligand,

  19. Emprego de catalisadores à base de níquel para homo- e copolimerização de estireno The use of nickel-based catalysts for homo-and copolymerization of styrene

    Directory of Open Access Journals (Sweden)

    Luis Carlos Ferreira Jr.

    2004-12-01

    Full Text Available This review deals with the homo- and copolymerization of styrene with nickel catalysts. The catalytic activity, polymer stereoregularity, polymer molecular weight and polydispersity are dependent upon nickel ligands and reaction parameters. Catalysts supported on silica, treated with methylaluminoxane (MAO, have shown higher stereospecificity and activity compared to homogeneous ones. The influence of these parameters is discussed focusing on the elucidation of some aspects of the polymerization mechanism.

  20. Factors affecting the long-term stability of mesoporous nickel-based catalysts in combined steam and dry reforming of methane

    OpenAIRE

    Jabbour, K.; El Hassan, N.; Davidson, A.; Casale, S.; Massiani, Pascale

    2016-01-01

    International audience; An ordered mesoporous " one-pot " nickel-alumina catalyst (5 wt% Ni) was synthesized using the evaporation-induced self-assembly method. Compared to an impregnated and to a non-porous catalysts, the ordered "one-pot" Ni-alumina sample displayed, after in-situ reduction, the highest and the most stable catalytic performances along 40h of run at 800°C in combined steam and dry reforming of methane, with conversion and selectivity values close to the thermodynamic expecte...

  1. Nickel-based xerogel catalysts: Synthesis via fast sol-gel method and application in catalytic hydrogenation of p-nitrophenol to p-aminophenol

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jin; Wang, Qiang; Fan, Dongliang; Ma, Lirong; Jiang, Deli; Xie, Jimin, E-mail: xiejm391@sohu.com; Zhu, Jianjun, E-mail: zhjj029@sina.com

    2016-09-30

    Graphical abstract: In order to investigate the roles of three-dimensional network structure and calcium on Ni catalysts, the Ni, Ni-Al{sub 2}O{sub 3}, Ni-Ca-Al{sub 2}O{sub 3} xerogel catalysts were successfully synthesized via the fast sol-gel process and chemical reduction method. - Highlights: • Epoxide-driven sol-gel and chemical reduction method subsequently were used to prepare Ni, Ni-Al{sub 2}O{sub 3} and Ni-Ca-Al{sub 2}O{sub 3} catalysts. • Three-dimensional network structure of the gel was employed to adjust the size and distribution of Ni nanoparticles. • Calcium was employed to shorten the gelation time, improve the nickel dispersion, decrease thenickel particle size and strengthen the Ni-Al{sub 2}O{sub 3} interaction. • The rate constants of Ni-Ca-Al2O3 catalysts (2.85 × 10{sup −3} s{sup −1}) is 2.8 times higher than the Ni catalysts (1.02 × 10{sup −3} s{sup −1}) and 2 times higher than the Ni-Al{sub 2}O{sub 3} catalysts(1.42 × 10{sup −3} s{sup −1}). • After 5 cycles, the conversion of PNP to PAP catalyzed by Ni, Ni-Al{sub 2}O{sub 3}, Ni-Ca-Al{sub 2}O{sub 3} remained 85%, 82%, 80%, respectively. - Abstract: In order to investigate the roles of three-dimensional network structure and calcium on Ni catalysts, the Ni, Ni-Al{sub 2}O{sub 3}, Ni-Ca-Al{sub 2}O{sub 3} xerogel catalysts were successfully synthesized via the fast sol-gel process and chemical reduction method. The crystal structure of three different catalysts was observed with X-ray powder diffraction (XRD). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and nitrogen adsorption-desorption were employed to investigate the role of network structure of xerogel catalysts and the size distribution of Ni nanoparticles. The catalyst composition was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) measurement and energy-dispersive X-ray spectroscopy (EDS). Temperature-programmed reduction (TPR) experiments were carried

  2. Synthesis of mesoporous zeolite catalysts by in situ formation of carbon template over nickel nanoparticles

    DEFF Research Database (Denmark)

    Abildstrøm, Jacob Oskar; Kegnæs, Marina; Hytoft, Glen

    2016-01-01

    A novel synthesis procedure for the preparation of the hierarchical zeolite materials with MFI structure based on the carbon templating method with in situ generated carbon template is presented in this study. Through chemical vapour deposition of coke on nickel nanoparticles supported on silica...... impregnation procedures and rather expensive chemicals are used. Removal of the carbon template by combustion results in zeolite single crystals with intracrystalline pore volumes between 0.28 and 0.48 cm3/g. The prepared zeolites are characterized by XRD, SEM, TEM and physisorption analysis. The isomerization...

  3. How nitric oxide affects the decomposition of supported nickel nitrate to arrive at highly dispersed catalysts

    NARCIS (Netherlands)

    Sietsma, J.R.A.; Friedrich, H.|info:eu-repo/dai/nl/304837350; Broersma, A.|info:eu-repo/dai/nl/311437532; Versluijs-Helder, M.|info:eu-repo/dai/nl/311472699; van Dillen, A.J.|info:eu-repo/dai/nl/111157625; de Jongh, P.E.|info:eu-repo/dai/nl/186125372; de Jong, K.P.|info:eu-repo/dai/nl/06885580X

    2008-01-01

    An explanation is put forward for the beneficial effect of thermal decomposition of supported Ni3(NO3)2(OH)4 in NO/He flow (0.1–1 vol%) that enables preparation of well-dispersed (3–5 nm particles) 24 wt% Ni-catalysts via impregnation and drying using aqueous [Ni(OH2)6](NO3)2 precursor solution.

  4. Electron microscopy study of the deactivation of nickel based catalysts for bio oil hydrodeoxygenation

    DEFF Research Database (Denmark)

    Gardini, Diego; Mortensen, Peter Mølgaard; Carvalho, Hudson W. P.

    2014-01-01

    Hydrodeoxygenation (HDO) is proposed as an efficient way to remove oxygen in bio-oil, improving its quality as a more sustainable alternative to conventional fuels in terms of CO2 neutrality and relative short production cycle [1]. Ni and Ni-MoS2 nanoparticles supported on ZrO2 show potential as ...... in order to investigate the oxidation of Ni-MoS2/ZrO2 catalyst active phase as a function of different HDO reaction conditions and using methanol as a model molecule for bio-oil.......Hydrodeoxygenation (HDO) is proposed as an efficient way to remove oxygen in bio-oil, improving its quality as a more sustainable alternative to conventional fuels in terms of CO2 neutrality and relative short production cycle [1]. Ni and Ni-MoS2 nanoparticles supported on ZrO2 show potential...... as high-pressure (100 bar) catalysts for purification of bio-oil by HDO. However, the catalysts deactivate in presence of sulfur, chlorine and potassium species, which are all naturally occurring in real bio-oil. The deactivation mechanisms of the Ni/ZrO2 have been investigated through scanning...

  5. Photodegradation of Methyl Green by Nickel-Dimethylglyoxime/ZSM-5 Zeolite as a Heterogeneous Catalyst

    Directory of Open Access Journals (Sweden)

    Alireza Nezamzadeh-Ejhieh

    2013-01-01

    Full Text Available Ni-DMG/ZSM-5 zeolite was prepared by ion exchange and complexation procedures. FT-IR, XRD, SEM, TG, and DTG methods were used for characterization of the raw and modified samples. The prepared composite was used as a catalyst in the photodegradation process of an aqueous solution methyl green (MG dye under UV irradiation. The effect of key operating parameters such as catalyst dosage, temperature, the initial concentration of the dye, and pH of the samples was studied on the degradation extent of the dye. UV-Vis spectrophotometric measurements were performed for determination of the decolorization and mineralization extents. The optimal operation parameters were found as follows: , temperature of 60°C, 0.6 g L−1 of the catalyst, and 40 ppm of the dye concentration. The Ni-DMG particles out of zeolite framework did not show significant degradation efficiency. The degradation process obeys the first-order kinetic.

  6. Novel Anion Exchange Resin-based Catalyst for Liquid-phase Methanol Synthesis at 373–393 K

    National Research Council Canada - National Science Library

    Aika, Ken-ichi; Kobayashi, Hidenobu; Harada, Kenji; Inazu, Koji

    2004-01-01

    A thermo-stable anion exchange resin–Raney Cu system was found as the most effective solid catalyst for low-temperature liquid-phase methanol synthesis at 373 to 393 K under 5.0 MPa of syngas (2H2/CO). With the catalyst...

  7. Determination of the kinetic parameters of the Sabatier reaction over nickel catalyst from the critical ignition conditions

    Energy Technology Data Exchange (ETDEWEB)

    Naumov, V.A.; Gavrilov, L.I.

    1979-11-01

    In a continuing study of the kinetics of the Sabatier reaction, Soviet researchers applied a thermokinetic method to determine the activation energy and the order of the reaction rate with respect to CO/sub 2/ and H/sub 2/ in the hydrogenation of CO/sub 2/ to CH/sub 4/ and H/sub 2/O over a nickel catalyst. The results agree with earlier conclusions that with large H/sub 2//CO/sub 2/ ratios and temperatures less than 520/sup 0/F (270/sup 0/C), the kinetics of the reaction follow an equation of the first order with respect to CO/sub 2/. The values of the activation energy obtained by three kinetic methods agree reasonably well: thermokinetic, 100.9 Btu (106.4 kj)/mol; flow-through/circulating, 107.2 Btu (113.1 kj)/mol; flow-though differential, 102.1 Btu (107.7 kj)/mol.

  8. Molecularly Tailored Nickel Precursor and Support Yield a Stable Methane Dry Reforming Catalyst with Superior Metal Utilization.

    Science.gov (United States)

    Margossian, Tigran; Larmier, Kim; Kim, Sung Min; Krumeich, Frank; Fedorov, Alexey; Chen, Peter; Müller, Christoph R; Copéret, Christophe

    2017-05-24

    Syngas production via the dry reforming of methane (DRM) is a highly endothermic process conducted under harsh conditions; hence, the main difficulty resides in generating stable catalysts. This can, in principle, be achieved by reducing coke formation, sintering, and loss of metal through diffusion in the support. [{Ni(μ(2)-OCHO)(OCHO)(tmeda)}2(μ(2)-OH2)] (tmeda = tetramethylethylenediamine), readily synthesized and soluble in a broad range of solvents, was developed as a molecular precursor to form 2 nm Ni(0) nanoparticles on alumina, the commonly used support in DRM. While such small nanoparticles prevent coke deposition and increase the initial activity, operando X-ray Absorption Near-Edge Structure (XANES) spectroscopy confirms that deactivation largely occurs through the migration of Ni into the support. However, we show that Ni loss into the support can be mitigated through the Mg-doping of alumina, thereby increasing significantly the stability for DRM. The superior performance of our catalytic system is a direct consequence of the molecular design of the metal precursor and the support, resulting in a maximization of the amount of accessible metallic nickel in the form of small nanoparticles while preventing coke deposition.

  9. Carbon-Nanotube-Supported Bio-Inspired Nickel Catalyst and Its Integration in Hybrid Hydrogen/Air Fuel Cells.

    Science.gov (United States)

    Gentil, Solène; Lalaoui, Noémie; Dutta, Arnab; Nedellec, Yannig; Cosnier, Serge; Shaw, Wendy J; Artero, Vincent; Le Goff, Alan

    2017-02-06

    A biomimetic nickel bis-diphosphine complex incorporating the amino acid arginine in the outer coordination sphere was immobilized on modified carbon nanotubes (CNTs) through electrostatic interactions. The functionalized redox nanomaterial exhibits reversible electrocatalytic activity for the H2 /2 H(+) interconversion from pH 0 to 9, with catalytic preference for H2 oxidation at all pH values. The high activity of the complex over a wide pH range allows us to integrate this bio-inspired nanomaterial either in an enzymatic fuel cell together with a multicopper oxidase at the cathode, or in a proton exchange membrane fuel cell (PEMFC) using Pt/C at the cathode. The Ni-based PEMFC reaches 14 mW cm(-2) , only six-times-less as compared to full-Pt conventional PEMFC. The Pt-free enzyme-based fuel cell delivers ≈2 mW cm(-2) , a new efficiency record for a hydrogen biofuel cell with base metal catalysts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Hydrogen production by dry reforming of methane with carbon dioxide in one-dimensional nickel-based catalysts; Produccion de hidrogeno mediante el reformado seco de metano con dioxido de carbono en catalizadores unidimensionales a base de niquel

    Energy Technology Data Exchange (ETDEWEB)

    Lopez U, A. C.

    2016-07-01

    The main objective of this thesis is development of nickel catalysts supported over 1D matrix of cerium oxide, to be used in dry reforming methane reaction with carbon dioxide for hydrogen production. The catalysts were characterized by: Temperature Programmed Reduction (TPR), Scanning Electronic Microscopy (Sem), Surface Area (Bet method) an X Ray Diffraction (XRD). The TPR technique allowed to define reduction temperature of the active phase in the catalyst, Sem technique showed that the CeO{sub 2} matrix had a nano rod morphology. XRD allowed to identify the crystalline phases of the catalysts. Finally, the catalysts were tested in the dry reforming methane reaction, high catalytic activity and hydrogen production were performed at 700 degrees Celsius and the catalyst with 30 wt.% of nickel. (Author)

  11. Nanostructured Co3O4grown on nickel foam: An efficient and readily recyclable 3D catalyst for heterogeneous peroxymonosulfate activation.

    Science.gov (United States)

    Yuan, Ruixia; Hu, Lin; Yu, Peng; Wang, Huaiyuan; Wang, Zhaohui; Fang, Jingyun

    2018-05-01

    Cobalt-based heterogeneous catalyst has been recognized as one of most efficient activators for peroxymonosulfate (PMS) decomposition, but usually suffers from the poor stability and difficulty to recover and reuse. Here easily recyclable cobalt oxide (Co 3 O 4 ) nanowires and nanoflowers grown on nickel foam (NF) are fabricated by a hydrothermal and calcination method. The prepared 3D Co 3 O 4 /NF catalyst is characterized and applied as a heterogeneous catalyst for PMS activation to generate sulfate radicals for decomposition of Acid Orange 7 (AO7). The results show that the AO7 degradation rate increases with cobalt loading and PMS dosage, but decreases with the increase of solution pH. The Co 3 O 4 /NF catalyst using 2 mM Co(NO 3 ) 2 ·6H 2 O as cobalt source exhibits highest activity, and almost complete decolorization could be achieved within 30 min. The diverse effects of coexisting anions (SO 4 2- , HCO 3 - , NO 3 - and Cl - ) on AO7 degradation are observed and explained. After 10 consecutive runs, excellent catalytic reactivity of the catalyst remains while the level of leached cobalt during the catalyst usage is much lower than the maximum allowable concentration in drinking and natural water. More importantly, the macroscopic Co 3 O 4 /NF catalyst shows advantage of easy recycling after application compared to traditional catalysts. It is believed that the as-prepared Co 3 O 4 /NF is promising to be an effective and green heterogeneous catalyst for PMS activation to degrade organic pollutants for environmental application. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. H{sub 2} production from CH{sub 4} decomposition: Regeneration capability and performance of nickel and rhodium oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, M.E.; Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie n 2, Cantoblanco, 28049 Madrid (Spain); Hori, C.E. [Faculdade de Engenharia Quimica, Universidade Federal de Uberlandia, Av. Joao Naves de Avila 2121, Campus Santa Monica, Bloco 1K, 38400-902 Uberlandia, MG (Brazil); Goldwasser, M.R. [Centro de Catalisis Petroleo y Petroquimica, Escuela de Quimica, Facultad de Ciencias, Universidad Central de Venezuela, Apartado 47102, Los Chaguaramos, Caracas (Venezuela); Griboval-Constant, A. [Unite de Catalyse et Chimie du Solide, UMR CNRS 8181, U.S.T.L., Batiment C3, 59655, Villeneuve D' Ascq, Cedex (France)

    2008-09-15

    Nickel-lanthanum (LaNiO{sub 3}) and nickel-rhodium-lanthanum (LaNi{sub 0.95}Rh{sub 0.05}O{sub 3}) perovskite-type oxide precursors were synthesized by different methodologies (co-precipitation, sol-gel and impregnation). They were reduced in an H{sub 2} atmosphere to produce nickel and rhodium nanoparticles on the La{sub 2}O{sub 3} substrate. All samples were tested in the catalytic decomposition of CH{sub 4}. Methane decomposed into carbon and H{sub 2} at reaction temperatures as low as 450 C - no other reaction products were observed. Conversions were in the range of 14-28%, and LaNi{sub 0.95}Rh{sub 0.05}O{sub 3} synthesized by co-precipitation was the most active catalyst. All catalysts maintained sustained activity even after massive carbon deposition indicating that these deposits are of the nanotube-type, as confirmed by transmission electron microscopy (TEM). The reaction seems to occur in a way that a nickel or rhodium crystal face is always clean enough to expose sufficient active sites to make the catalytic process continue. The samples were subjected to a reduction-oxidation-reduction cycle and in situ analyses confirmed the stability of the perovskite structure. All diffraction patterns showed a phase change around 400 C, due to reduction of LaNiO{sub 3} to an intermediate La{sub 2}Ni{sub 2}O{sub 5} structure. When the reduction temperatures reach 600 C, this structure collapses through the formation of Ni{sup 0} crystallites deposited on the La{sub 2}O{sub 3}. Under oxidative conditions, the perovskite system is recomposed with nickel re-entering the LaNiO{sub 3} framework structure accounting for the regenerative capability of these solids. (author)

  13. Examining the Utility of the New Raney Vocabulary Measure Alongside the WAIS-III.

    Science.gov (United States)

    Ferguson, Ryan J; Roy-Charland, Annie; Dickinson, Joël

    2018-01-29

    Psychometric tests related to vocabulary assessments are, for the most part, restricted in their use by trained professionals and/or are costly. These restrictions limit their use, especially for research purposes. To circumvent these limitations, the Raney Vocabulary Measure was created for assessing vocabulary proficiency, specifically for research purposes. The measure consists of 30 questions where participants were instructed to choose the best definition of each word. The purpose of the study was to examine the utility of the new measure using the highly standardized but protected Wechsler Adult Intelligence Scale. Results from the linear combination of the subscales revealed the significant prediction of the Raney Vocabulary Measure, with the Vocabulary subtest contributing most to the unique variance. These results support that the test examines vocabulary ability. The current results are promising as the test would allow for greater accessibility for researchers who do not have access to restricted psychometric tests.

  14. Nickel-based electrodeposits as potential cathode catalysts for hydrogen production by microbial electrolysis

    Science.gov (United States)

    Mitov, M.; Chorbadzhiyska, E.; Nalbandian, L.; Hubenova, Y.

    2017-07-01

    The development of cost-effective cathodes, operating at neutral pH and ambient temperatures, is a crucial challenge for the practical application of microbial electrolysis cell (MEC) technology. In this study, NiW and NiMo co-deposits produced by electroplating on Ni-foam are explored as cathodes in MEC. The fabricated electrodes exhibit higher corrosion stability and enhanced electrocatalytic activity towards hydrogen evolution reaction in neutral electrolyte compared to the bare Ni-foam. NiW/Ni-foam electrodes possess six times higher intrinsic catalytic activity, estimated from data obtained by linear voltammetry and chronoamperometry. The newly developed electrodes are applied as cathodes in single-chamber membrane-free MEC reactors, inoculated with wastewater and activated sludge from a municipal wastewater treatment plant. Cathodic hydrogen recovery of 79% and 89% by using NiW and NiMo cathodes, respectively, is achieved at applied voltage of 0.6 V. The obtained results reveal potential for practical application of used catalysts in MEC.

  15. High hydrogen desorption properties of Mg-based nanocomposite at moderate temperatures: The effects of multiple catalysts in situ formed by adding nickel sulfides/graphene

    Science.gov (United States)

    Xie, Xiubo; Chen, Ming; Liu, Peng; Shang, Jiaxiang; Liu, Tong

    2017-12-01

    Nickel sulfides decorated reduced graphene oxide (rGO) has been produced by co-reducing Ni2+ and graphene oxide (GO), and is subsequently ball milled with Mg nanoparticles (NPs) produced by hydrogen plasma metal reaction (HPMR). The nickel sulfides of about 800 nm completely in situ change to MgS, Mg2Ni and Ni multiple catalysts after first hydrogenation/dehydrogenation process at 673 K. The Mg-5wt%NiS/rGO nanocomposite shows the highest hydrogen desorption kinetics and capacity properties, and the catalytic effect order of the additives is NiS/rGO, NiS and rGO. At 573 K, the Mg-NiS/rGO nanocomposite can quickly desorb 3.7 wt% H2 in 10 min and 4.5 wt% H2 in 60 min. The apparent hydrogen absorption and desorption activation energies of the Mg-5wt%NiS/rGO nanocomposite are decreased to 44.47 and 63.02 kJ mol-1, smaller than those of the Mg-5wt%rGO and Mg-5wt%NiS samples. The best hydrogen desorption properties of the Mg-5wt%NiS/rGO nanocomposite can be explained by the synergistic catalytic effects of the highly dispersed MgS, Mg2Ni and Ni catalysts on the rGO sheets, and the more nucleation sites between the catalysts, rGO sheets and Mg matrix.

  16. Catalysts prepared from copper-nickel ferrites for the steam reforming of methanol

    Science.gov (United States)

    Huang, Yung-Han; Wang, Sea-Fue; Tsai, An-Pang; Kameoka, Satoshi

    2015-05-01

    In this study, Fe3O4-supported Cu and Ni catalysts are prepared through reduction of Cu-Ni (Ni1-xCuxFe2O4) ferrites. The Cu-Ni ferrites, synthesized using a solid-state reaction method, are reduced at temperatures from 240 °C to 500 °C in a H2 atmosphere. All ferrites are characterized with granular morphology and a smooth particle surface before reduction. For the CuFe2O4, Ni0.5Cu0.5Fe2O4 and NiFe2O4 ferrites reduced at 240, 300, and 400 °C, respectively, nanosized Cu and/or Ni particles (5-32 nm) and mesopores (5-30 nm) are distributed and adhered on the surfaces of Fe3O4 supports. After increasing the reduction temperature of NiFe2O4 ferrite to 500 °C, the Ni particles and mesopores disappear from the Fe3O4 surfaces, which is due to the formation of a Fe-Ni alloy covering on the Fe3O4 surfaces. The CuFe2O4 ferrite after H2 reduction at 240 °C exhibits the highest H2 production rate of 149 ml STP/min g-cat at 360 °C. The existence of Ni content in the Cu-Ni ferrites enhances the reverse water gas shift reaction, and raises the CO selectivity while reducing the CO2 selectivity. Formation of a Fe-Ni alloy exaggerates the trend and poisons the H2 production rate.

  17. Liquid phase in situ hydrodeoxygenation of biomass-derived phenolic compounds to hydrocarbons over bifunctional catalysts

    Science.gov (United States)

    Junfeng Feng; Chung-yun Hse; Zhongzhi Yang; Kui Wang; Jianchun Jiang; Junming Xu

    2017-01-01

    The objective of this study was to find an effective method for converting renewable biomass-derived phenolic compounds into hydrocarbons bio-fuel via in situ catalytic hydrodeoxygenation. The in situ hydrodeoxygenation of biomass-derived phenolic compounds was carried out in methanol-water solvent over bifunctional catalysts of Raney Ni and HZSM-5 or H-Beta. In the in...

  18. Cross-coupling of nonactivated alkyl halides with alkynyl Grignard reagents: a nickel pincer complex as the catalyst.

    OpenAIRE

    Vechorkin Oleg; Godinat Aurélien; Scopelliti Rosario; Hu Xile

    2011-01-01

    The nickel pincer complex 1 catalyzes the cross coupling of the title compounds with remarkable substrate scope and functional group tolerance. A nickel/alkynyl species was isolated and shown to be catalytically competent. THF=tetrahydrofuran O TMEDA=bis[2 (NN dimethylaminoethyl)] ether.

  19. Synthesis of liquid menthol by hydrogenation of dementholized peppermint oil over Ni catalysts

    Directory of Open Access Journals (Sweden)

    Debora L. Manuale

    2010-01-01

    Full Text Available Hydrogenation of (--menthone and (+-isomenthone was studied at 2.7 MPa and 100 ºC. The objective was to produce a liquid menthol mixture rich in (--menthol from dementholized peppermint oil. Ni-based catalysts were tested and compared for this reaction: a 6 and 12% Ni dispersed into a nonstoichiometric magnesium aluminate (Ni-Mg-Al with spinel structure; b Ni-Raney catalyst. Both types of catalysts were active for (--menthone and (+-isomenthone hydrogenation. Lower conversion but higher selectivity to (--menthol was obtained with Ni-Mg-Al catalysts. However, they rapidly lost their activity. Instead Ni-Raney catalysts kept its original activity even after several hydrogenation runs.

  20. Raney copper catalysts for the water-gas shift reaction: I. Preparation, activity and stability

    CSIR Research Space (South Africa)

    Mellor, JR

    1997-12-23

    Full Text Available disper- sion is expressed in terms of the ratio of the total number of surface atoms to the total number of metal atoms present. Copper particle volume-area mean diameter (dvA) was calculated according to the pro- cedure outlined by Anderson et al...

  1. A potentially implantable glucose fuel cell with Raney-platinum film electrodes for improved hydrolytic and oxidative stability

    Energy Technology Data Exchange (ETDEWEB)

    Kerzenmacher, S.; Kraeling, U.; Metz, T.; von Stetten, F. [Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 103, D-79110 Freiburg (Germany); Zengerle, R. [Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 103, D-79110 Freiburg (Germany); Centre for Biological Signalling Studies (bioss), Albert-Ludwigs-Universitaet Freiburg (Germany)

    2011-02-01

    We present an improved abiotically catalyzed glucose fuel cell, intended as energy harvesting tissue implantable power supply for medical implants. The fuel cell is constructed from a Raney-platinum film cathode deposited on a silicon substrate with micro-machined feedholes for glucose permeability, arranged in front of a Raney-platinum film anode. A novelty is the application of platinum for both electrodes and the complete abdication of hydrogel binders. This overcomes the limited stability against hydrolytic and oxidative attack encountered with previous glucose fuel cells fabricated from activated carbon particles dispersed in a hydrogel matrix. During performance characterization in phosphate buffered saline under physiological concentrations of glucose and oxygen the diffusion resistance to be expected from tissue capsule formation was taken into account. Despite the resulting limited oxygen supply, the Raney-platinum fuel cells exhibit a power density of up to (4.4 {+-} 0.2) {mu}W cm{sup -2} at 7.0% oxygen saturation. This exceeds the performance of our previous carbon-based prototypes, and can be attributed to the higher catalytic activity of platinum cathodes and in particular the increased oxygen tolerance of the Raney-platinum film anodes. (author)

  2. Functionalized SBA-15 supported nickel (II)-oxime-imine catalysts for liquid phase oxidation of olefins under solvent-free conditions

    Science.gov (United States)

    Paul, Luna; Banerjee, Biplab; Bhaumik, Asim; Ali, Mahammad

    2016-05-01

    A new oxime-imine functionalized highly ordered mesoporous SBA-15 (SBA-15-NH2-DAMO) has been synthesized via post-synthesis functionalization of SBA-15 with 3-aminopropyl-triethoxysilane followed by the Schiff base condensation with diacetylmonooxime, which was further reacted with Ni(ClO4)2 to yield the functionalized nickel catalyst SBA-15-NH2-DAMO-Ni. All the synthesized materials were thoroughly characterized using different characterization techniques. It was found that SBA-15-NH2-DAMO-Ni catalyzes the one-pot oxidation of olefins like styrene, cyclohexene, cyclooctene, 1-hexene and 1-octene to the corresponding benzaldehyde, cyclohexene-1-ol and cyclooctene-oxide, respectively under solvent-free conditions by using tert-butylhydroperoxide as oxidant.

  3. Preparation of nickel ferrite/carbon nanotubes composite by microwave irradiation technique for use as catalyst in photo-fenton reaction

    Energy Technology Data Exchange (ETDEWEB)

    Foletto, E.L.; Rigo, C.; Severo, E.C.; Mazutti, M.A.; Dotto, G.L.; Jahn, S.L.; Sales, J.C. [Universidade Federal de Santa Maria (UFSM), RS (Brazil); Chiavone-Filho, O. [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil); Gundel, A.; Lucchese, M. [Universidade Federal do Pampa (UNIPAMPA), Bage, RS (Brazil)

    2016-07-01

    Full text: Nickel ferrite/multi-walled carbon nanotubes (NiFe2O4/MWCNTs) composite has been rapidly synthesized via microwave irradiation technique. The structural properties of the formed product was investigated by X-ray diffraction (XRD), N2 adsorption/desorption isotherms, thermogravimetric analysis (TGA), Raman spectroscopy and, scanning electron microscopy (SEM). The catalytic behavior of composite material was evaluated by the degradation of Amaranth dye in the photo-Fenton reaction under visible light irradiation. The overall results showed that the prepared composite was successfully synthesized, demonstrating good performance in the dye degradation, with higher degradation rate compared to the NiFe2O4. The high efficiency in dye degradation can be attributed to synergism between NiFe2O4 and MWCNTs. Therefore, NiFe2O4/MWCNTs composite can be used as promising photo-Fenton catalyst to degrade Amaranth dye from aqueous solutions. (author)

  4. Controlled surface segregation leads to efficient coke-resistant nickel/platinum bimetallic catalysts for the dry reforming of methane

    KAUST Repository

    Li, Lidong

    2015-02-03

    Surface composition and structure are of vital importance for heterogeneous catalysts, especially for bimetallic catalysts, which often vary as a function of reaction conditions (known as surface segregation). The preparation of bimetallic catalysts with controlled metal surface composition and structure is very challenging. In this study, we synthesize a series of Ni/Pt bimetallic catalysts with controlled metal surface composition and structure using a method derived from surface organometallic chemistry. The evolution of the surface composition and structure of the obtained bimetallic catalysts under simulated reaction conditions is investigated by various techniques, which include CO-probe IR spectroscopy, high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, extended X-ray absorption fine structure analysis, X-ray absorption near-edge structure analysis, XRD, and X-ray photoelectron spectroscopy. It is demonstrated that the structure of the bimetallic catalyst is evolved from Pt monolayer island-modified Ni nanoparticles to core-shell bimetallic nanoparticles composed of a Ni-rich core and a Ni/Pt alloy shell upon thermal treatment. These catalysts are active for the dry reforming of methane, and their catalytic activities, stabilities, and carbon formation vary with their surface composition and structure. The reform of reforming: A series of alumina-supported Ni/Pt bimetallic nanoparticles (NPs) with controlled surface composition and structure are prepared. Remarkable surface segregation for these bimetallic NPs is observed upon thermal treatment. These bimetallic NPs are active catalysts for CO2 reforming of CH4, and their catalytic activities, stabilities, and carbon formation vary with their surface composition and structure.

  5. Toward stable nickel catalysts for aqueous phase reforming of biomass-derived feedstock under reducing and alkaline conditions

    NARCIS (Netherlands)

    Van Haasterecht, T.; Ludding, C. C I; De Jong, K. P.; Bitter, J. H.

    2014-01-01

    Nickel nanoparticles supported on carbon nanofibers (CNF) can be stabilized in aqueous phase processes at elevated temperatures and pressures by tuning the reaction conditions to control Ni oxidation and leaching. As a showcase, Ni/CNF was used for the production of hydrogen via aqueous phase

  6. Promoting effects of thoria on the nickel-manganese mixed oxide catalysts for the aerobic oxidation of benzyl alcohol

    Directory of Open Access Journals (Sweden)

    S.S.P. Sultana

    2017-05-01

    Full Text Available Due to the recent advancement in the development of various characterization techniques, mixed metal oxide (MMO based catalysts have gained tremendous attention in the field of catalysis. In this study, we demonstrated the synthesis of a series of novel MMO based catalysts by a facile co-precipitation method. The detailed structure and composition of thoria promoted NiMnO catalysts was investigated using various microscopic and spectroscopic techniques such as, SEM, EDAX, XRD, TGA, BET and TPR. In order to study the effect of the content of thorium oxide on the catalytic activity of the as-prepared material various samples were prepared by the addition of low quantities of thorium oxide with 1%, 3% and 5% on NiMnO. The catalytic performances of the as-prepared catalysts were evaluated towards the aerobic oxidation of benzyl alcohol using molecular oxygen as oxidant. Furthermore, in order to investigate the effect of the calcination temperatures on the catalytic activities of the as-prepared materials, the samples were calcined at three different temperatures at 300 °C, 400 °C and 500 °C. The catalysts displayed significant enhancement in catalytic activity towards the catalytic conversion of benzyl alcohol (C6H5CH2OH to benzaldehyde (C6H5CHO. Detailed kinetic studies of the reactions using gas chromatography have revealed that the variation of calcination temperature and the percentage of thoria had significant effect on the catalytic performances of the materials. Among all synthesized catalysts ThO2-(5%-NiMnO catalyst calcined at 400 °C exhibited the highest catalytic performance and stability for the selective oxidation of alcohols.

  7. Influence of supports on catalytic behavior of nickel catalysts in carbon dioxide reforming of toluene as a model compound of tar from biomass gasification.

    Science.gov (United States)

    Kong, Meng; Fei, Jinhua; Wang, Shuai; Lu, Wen; Zheng, Xiaoming

    2011-01-01

    A series of supported Ni catalysts including Ni/MgO, Ni/γ-Al2O3, Ni/α-Al2O3, Ni/SiO2 and Ni/ZrO2 was tested in CO2 reforming of toluene as a model compound of tar from biomass gasification in a fluidized bed reactor, and characterized by the means of temperature programmed reduction with hydrogen (H2-TPR), XRD, TEM and temperature programmed oxidation (TPO). Combining the characterization results with the performance tests, the activity of catalyst greatly depended on Ni particles size, and the stability was affected by the coke composition. Both of them (Ni particle size and coke composition) were closely related to the interaction between nickel and support which would determine the chemical environment where Ni inhabited. The best catalytic performance was observed on Ni/MgO due to the strong interaction between NiO and MgO via the formation of Ni-Mg-O solid solution, and the highest dispersion of Ni particle in the basic environment. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Improved catalysts for hydrogen evolution reaction in alkaline solutions through the electrochemical formation of nickel-reduced graphene oxide interface.

    Science.gov (United States)

    Gutić, Sanjin J; Dobrota, Ana S; Leetmaa, Mikael; Skorodumova, Natalia V; Mentus, Slavko V; Pašti, Igor A

    2017-05-24

    H2 production via water electrolysis plays an important role in hydrogen economy. Hence, novel cheap electrocatalysts for the hydrogen evolution reaction (HER) are constantly needed. Here, we describe a simple method for the preparation of composite catalysts for H2 evolution, consisting in simultaneous reduction of the graphene oxide film, and electrochemical deposition of Ni on its surface. The obtained composites (Ni@rGO), compared to pure electrodeposited Ni, show an improved electrocatalytic activity towards HER in alkaline media. We found that the activity of the Ni@rGO catalysts depends on the surface composition (Ni vs. C mole ratio) and on the level of structural disorder of the rGO support. We suggest that HER activity is improved via Hads spillover from the Ni particles to the rGO support, where quick recombination to molecular hydrogen is favored. A deeper insight into such a mechanism of H2 production was achieved by kinetic Monte-Carlo simulations. These simulations enabled the reproduction of experimentally observed trends under the assumption that the support can act as a Hads acceptor. We expect that the proposed procedure for the production of novel HER catalysts could be generalized and lead to the development of a new generation of HER catalysts by tailoring the catalyst/support interface.

  9. Preparation of Raney-Ni gas diffusion electrode by filtration method for alkaline fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sleem-Ur-Rahman; Al-Saleh, M.A.; Al-Zakri, A.S.; Gultekin, S. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Chemical Emgineering

    1997-02-01

    A novel filtration method for preparation of gas diffusion electrodes for fuel cells is proposed. This method, which is a modification of the conventional dry method, has the merits of both wet and dry techniques. The electrode performance is improved due to better structure, controlled hydrophobicity and less compaction. To compare the effectiveness of the method, Raney-Ni/PTFE anodes for use in a KOH fuel cell were made. Their electrochemical performance was compared with similar electrodes produced by the dry method by other research groups, under the same conditions. The filtration method electrodes performed better between temperatures of 25{sup o}C and 75{sup o}C. The electrode exhibited no significant degradation of activity in the first 180 h at 100 mAcm{sup -2} anodic load. (author)

  10. Surface areas of turbostratic graphitic carbons prepared from a resin using nickel particles, 20 nm, as graphitization catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Oya, A.; Inoue, E.; Otani, S.; Marsh, H.

    1981-11-01

    Nickel particles were used to graphitize catalytically a non-graphitizing carbon to create a turbostratic graphitic material called the T/SUB/s-component. This method was examined by X-ray diffraction. Coals on heat treatment to temperatures >1270 K form T/SUB/s-component carbons. Therefore, considerations of the properties of the T/SUB/s-component carbon may have relevance to considerations of the operational performances of blast furnace coke. (22 refs.)

  11. Session 4: Hydrogen production from biomass gasification in a fluidized bed. Nickel catalyst for tar removal. European contract no. ENK5 - CT2000 - 00314

    Energy Technology Data Exchange (ETDEWEB)

    Swierczynski, D.; Courson, C.; Kiennemann, A. [Laboratoire des Materiaux, Surfaces et Procedes pour la Catalyse (LMSPC), UMR CNRS-ULP 7515, Ecole Europeenne Chimie Polymeres et Materiaux (ECPM), 67 - Strasbourg (France); Hofbauer, H.; Rauch, R.; Pfeifer, C. [Institute of Chemical Engineering, Vienna (Austria)

    2004-07-01

    olivine source. Ni/olivine catalyst was synthesised using the olivine A. The preparation method was scaled up for large amount (100 kg) of catalyst required in biomass gasifier. Biomass steam gasification tests were performed in the 100 kW{sub th} dual fluidized bed pilot with various Ni/olivine catalyst content (from 0 to 43%) in olivine as circulating fluidized bed. The catalyst showed high activity in steam reforming of methane as expected by the results from the laboratory scale experiments. On the other hand the tar content of the product gas could be reduced up to 75 % compared to the usage of natural olivine alone. The hydrogen volume fraction could be increased therefore up to 8 percentage points. An increase of the amount of catalyst in the bed material resulted in an increase of the water conversion as well as the tar reforming. The gas yield followed the same tendency. No significant difference of attrition could be showed between tests with various catalyst contents (from 0 to 43% in olivine). So attrition was not due to nickel loss. In fact, during experimental times up to 45 hours no deactivation of the catalyst could be observed. Previous results have pointed out that tar elimination by steam reforming led to an increase of hydrogen content in the product gas. To understand the decrease of tar content in biomass gasification with Ni/olivine catalyst model studies of tar removal were performed at laboratory scale in a fixed bed reactor. Toluene was chosen as tar model compound and Ni/olivine catalyst was tested in steam reforming of toluene in temperature range from 550 C to 850 C for steam to toluene ratio of 16. The efficiency of the Ni/olivine catalyst was shown clearly by the difference between Ni/olivine and olivine alone in toluene conversion versus reaction temperature. Hydrogen yield and products selectivities obtained at 850 C (gasification temperature) confirmed nickel influence in the orientation of biomass gasification reaction. In fact, with

  12. Nickel Dermatitis - Nickel Excretion

    DEFF Research Database (Denmark)

    Menné, T.; Thorboe, A.

    1976-01-01

    Nickel excretion in urine in four females -sensitive to nickel with an intermittent dyshidrotic eruption was measured with flameless atomic absorption. Excretion of nickel was found to be increased in association with outbreaks of vesicles. The results support the idea that the chronic condition...... was maintained by ingestion of nickel in food....

  13. Atomic Layer Deposition of Ultrathin Nickel Sulfide Films and Preliminary Assessment of Their Performance as Hydrogen Evolution Catalysts.

    Science.gov (United States)

    Çimen, Yasemin; Peters, Aaron W; Avila, Jason R; Hoffeditz, William L; Goswami, Subhadip; Farha, Omar K; Hupp, Joseph T

    2016-11-22

    Transition metal sulfides show great promise for applications ranging from catalysis to electrocatalysis to photovoltaics due to their high stability and conductivity. Nickel sulfide, particularly known for its ability to electrochemically reduce protons to hydrogen gas nearly as efficiently as expensive noble metals, can be challenging to produce with certain surface site compositions or morphologies, e.g., conformal thin films. To this end, we employed atomic layer deposition (ALD), a preeminent method to fabricate uniform and conformal films, to construct thin films of nickel sulfide (NiSx) using bis(N,N'-di-tert-butylacetamidinato)nickel(II) (Ni(amd)2) vapor and hydrogen sulfide gas. Effects of experimental conditions such as pulse and purge times and temperature on the growth of NiSx were investigated. These revealed a wide temperature range, 125-225 °C, over which self-limiting NiSx growth can be observed. In situ quartz crystal microbalance (QCM) studies revealed conventional linear growth behavior for NiSx films, with a growth rate of 9.3 ng/cm2 per cycle being obtained. The ALD-synthesized films were characterized using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) methods. To assess the electrocatalyitic activity of NiSx for evolution of molecular hydrogen, films were grown on conductive-glass supports. Overpotentials at a current density of 10 mA/cm2 were recorded in both acidic and pH 7 phosphate buffer aqueous reaction media and found to be 440 and 576 mV, respectively, with very low NiSx loading. These results hint at the promise of ALD-grown NiSx materials as water-compatible electrocatalysts.

  14. Preparation of mono- or zerovalent nickel by single or successive one-electron-transfer steps in the photoreduction of silica-supported nickel catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Bonneviot, L.; Cai, F.X.; Che, M.; Kermarec, M.; Legendre, O.; Lepetit, C.; Olivier, D.

    1987-11-05

    Ni/SiO/sub 2/ supported catalysts prepared by competitive cation exchange can be reduced by UV irradiation in hydrogen at 77 K to lead by a one-electron process to Ni/sup +/ species. These Ni/sup +/ ions which exhibit an EPR signal at g/sub 1/ = 2.68, g/sub 2/ = 2.32, and g/sub 3/ = 2.007 and a band at 838 nm in the UV-vis and near-IR reflectance spectra bind molecular hydrogen to form (similarly ordered Ni(H/sub 2/))/sup +/ pseudotetrahedral surface complexes. The photoreduction process in carbon monoxide occurs appreciably only at 25/sup 0/C and depends on the CO pressure. It is a one-electron-reduction process, and (Ni(CO)/sub n/)/sup +/ species (n = 2-4) are observed by EPR and IR for pressures above 10 Torr. For lower pressures, the formation of metal is observed by IR and ferromagnetic resonance via the reduction by two consecutive one-electron-transfer steps. The first step proceeds from the photoproduction of (Ni/sup +/-O/sup -/)* excited states. The second step is due to the release of electrons from a reservoir which has been tentatively identified to pseudo-carbonates characterized by IR bands at 1750-1850 cm/sup -1/ and by TPD peaks of CO at 803 K and of CO/sub 2/ at 513 and 803 K. The formation of the latter species is the result of the quenching of the excited state by CO molecules which react with the O/sup -/ activated surface oxygens to lead to CO/sub 2//sup -/ which with O/sup 2 -/ ions generates CO/sub 3//sup 3 -/ radical ions.

  15. Nickel phosphide nanoparticles decorated nitrogen and phosphorus co-doped porous carbon as efficient hybrid catalyst for hydrogen evolution

    Science.gov (United States)

    Lin, Yan; Zhang, Jun; Pan, Yuan; Liu, Yunqi

    2017-11-01

    The design of efficient and robust Ni2P-based hybrid catalysts for hydrogen evolution reaction (HER) is still in challenge. In this work, a hybrid catalyst composed of monodispersed Ni2P nanoparticles (NPs) and N, P co-doped porous carbon (NPPC) was synthesized through a facile thermal decomposition and used as an efficient electrocatalyst for the HER in 0.5 M H2SO4 solution. Series technologies including X-ray diffraction, Raman, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and N2 sorption are used to characterize the as-synthesized catalysts. The electrochemisty experiments suggested that the as-synthesized Ni2P/NPPC displayed efficient electrocatalytic performance with a low onset overpotential (51 mV), small Tafel slope (74 mV dec-1), high exchange current density (0.12 mA cm-2), large electrochemical double-layer capacitance (21.97 mF cm-2) and high conductivity for the HER. The needed overpotentials are 159 and 184 mV to reach to the current density of 10 and 20 mA cm-2, respectively. Simultaneously, Ni2P/NPPC also displayed good stability in acid solution. The more defects and active sites on the porous carbon which are offered by the co-doped N and P atoms as well as the synergistic effect between NPPC and Ni2P NPs are contributed to the excellent catalytic performance for HER. The current study suggests that introducing the N, P heteroatoms co-doped carbon materials to the Ni2P-based catalysts could enhance HER electrocatalytic performance efficiently.

  16. Computational Investigation of the Thermochemistry and Kinetics of Steam Methane Reforming Over a Multi-Faceted Nickel Catalyst

    KAUST Repository

    Blaylock, D. Wayne

    2011-08-20

    A microkinetic model of steam methane reforming over a multi-faceted nickel surface using planewave, periodic boundary condition density functional theory is presented. The multi-faceted model consists of a Ni(111) surface, a Ni(100) surface, and nickel step edge sites that are modeled as a Ni(211) surface. Flux and sensitivity analysis are combined to gain an increased understanding of the important reactions, intermediates, and surface facets in SMR. Statistical thermodynamics are applied to allow for the investigation of SMR under industrially-relevant conditions (e.g., temperatures in excess of 500 °C and pressures in excess of 1 bar). The most important surface reactions are found to occur at the under-coordinated step edge sites modeled using the Ni(211) surface as well as on the Ni(100) surface. The primary reforming pathway is predicted to be through C*+ O*→ CO*at high temperatures; however, hydrogen-mediated reactions such as C*+ OH*→ COH*and C.H.*+ O*→ CHO*are predicted to become more important at low temperatures. The rate-limiting reactions are predicted to be dissociative chemisorption of methane in addition to the aforementioned C-O addition reactions. © 2011 Springer Science+Business Media, LLC.

  17. Functionalized SBA-15 supported nickel (II)–oxime–imine catalysts for liquid phase oxidation of olefins under solvent-free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Luna [Department of Chemistry, Jadavpur University, Kolkata 700 032 (India); Banerjee, Biplab [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Bhaumik, Asim, E-mail: msab@iacs.res.in [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Ali, Mahammad, E-mail: m_ali2062@yahoo.com [Department of Chemistry, Jadavpur University, Kolkata 700 032 (India)

    2016-05-15

    A new oxime–imine functionalized highly ordered mesoporous SBA-15 (SBA-15-NH{sub 2}-DAMO) has been synthesized via post-synthesis functionalization of SBA-15 with 3-aminopropyl-triethoxysilane followed by the Schiff base condensation with diacetylmonooxime, which was further reacted with Ni(ClO{sub 4}){sub 2} to yield the functionalized nickel catalyst SBA-15-NH{sub 2}-DAMO-Ni. All the synthesized materials were thoroughly characterized using different characterization techniques. It was found that SBA-15-NH{sub 2}-DAMO-Ni catalyzes the one-pot oxidation of olefins like styrene, cyclohexene, cyclooctene, 1-hexene and 1-octene to the corresponding benzaldehyde, cyclohexene-1-ol and cyclooctene-oxide, respectively under solvent-free conditions by using tert-butylhydroperoxide as oxidant. - Graphical abstract: A new well characterized oxime–imine functionalized highly ordered mesoporous SBA-15-NH{sub 2}-DAMO-Ni complex catalyzes the one-pot oxidation of olefins under solvent free mild conditions.

  18. Nickel silicotungstate-decorated Pt photocathode as an efficient catalyst for triiodide reduction in dye-sensitized solar cells.

    Science.gov (United States)

    Jiang, Yanxia; Yang, Yulin; Zhu, Junjiang; Qiang, Liangsheng; Ye, Tengling; Li, Liang; Su, Ting; Fan, Ruiqing

    2016-11-14

    A new type of polyoxometalate material, K6SiW11O39Ni(H2O)·xH2O (denoted as SiW11Ni), was successfully synthesized and introduced to a dye-sensitized solar cell (DSSC) with modified traditional Pt as a novel composite counter electrode. The new counter electrode showed superior electrochemical catalytic activity for the reduction of I3(-) to I(-) in analysis utilizing a Tafel-polarization curve, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The DSSC assembled with the SiW11Ni/Pt photocathode exhibited an enhanced performance (7.03%) under the standard AM 1.5G illumination compared to the DSSC with a pristine Pt photocathode (6.65%). Furthermore, the DSSC based on the SiW11Ni/Pt photocathode had an increased light-harvesting efficiency and was very stable. The results demonstrate that SiW11Ni/Pt is an alternative and highly efficient counter electrode for dye-sensitized solar cells. Moreover, the facile design strategy is promising for fabricating efficient and inexpensive composite counter electrode catalysts for DSSCs.

  19. Study of Supported Nickel Catalysts Prepared by Aqueous Hydrazine Method. Hydrogenating Properties and Hydrogen Storage: Support Effect. Silver Additive Effect; Catalyseurs de nickel supportes prepares par la methode de l'hydrazine aqueuse. Proprietes hydrogenantes et stockage d'hydrogene. Effet du support. Effet de l'ajout d'argent

    Energy Technology Data Exchange (ETDEWEB)

    Wojcieszak, R

    2006-06-15

    We have studied Ni or NiAg nano-particles obtained by the reduction of nickel salts (acetate or nitrate) by hydrazine and deposited by simple or EDTA-double impregnation on various supports ({gamma}-Al{sub 2}O{sub 3}, amorphous or crystallized SiO{sub 2}, Nb{sub 2}O{sub 5}, CeO{sub 2} and carbon). Prepared catalysts were characterized by different methods (XRD, XPS, low temperature adsorption and desorption of N{sub 2}, FTIR and FTIR-Pyridine, TEM, STEM, EDS, H{sub 2}-TPR, H{sub 2}-adsorption, H{sub 2}-TPD, isopropanol decomposition) and tested in the gas phase hydrogenation of benzene or as carbon materials in the hydrogen storage at room temperature and high pressure. The catalysts prepared exhibited better dispersion and activity than classical catalysts. TOF's of NiAg/SiO{sub 2} or Ni/carbon catalysts were similar to Pt catalysts in benzene hydrogenation. Differences in support acidity or preparation method and presence of Ag as metal additive play a crucial role in the chemical reduction of Ni by hydrazine and in the final properties of the materials. Ni/carbon catalysts could store significant amounts of hydrogen at room temperature and high pressure (0.53%/30 bars), probably through the hydrogen spillover effect. (author)

  20. Catalytic Converter Developed By Washcoat Of γ-Alumina On Nickel Oxide (Nio Catalyst In FeCrAl Substrate For Exhaust Emission Control : A Review

    Directory of Open Access Journals (Sweden)

    Leman A.M.

    2016-01-01

    Full Text Available Automobile exhaust emission control is one of the trending issues in automobile research field. The existing catalytic converter using the noble metals of platinum (Pt, palladium (Pd and rhodium (Rd recently were in limited supply and higher in cost. There is a need for the automotive industry to produce ultra-low emitting vehicles at a reasonable cost. The objective of this study is to investigate the effectiveness of methods of fabrication of modified catalytic converter by approaching FeCrAl as a substrate which treated using ultrasonic bath technique to improve the exhaust emission control. The modified catalytic converter preparation will involve the ultrasonic bath process of FeCrAl foil which has fabricated as metallic monolith coated by γ-Al2O3 powder. Nickel as catalyst material will be prepared using electroplating process. The oxidation test will be conducted using a tube and automatic furnace in temperature of 1100°C for 100 hours. Mitsubishi 4G93 1800cc Petrol E.F.I with a multi -gas analyzer equipped with a hydraulic dynamometer will be used for emission measurements of HC, CO, and NOx in varying speed and load for both conditions with and without catalytic converter. The result will expect the γ-Al2O3 as the washcoat material that fully embedded to FeCrAl substrate with the combination of ultrasonic and electroplating technique will effectively convert the CO, NOx and HC to CO2, NO2 and H2O which means that catalytic converter is effective to improve exhaust emission control of diesel engine. The FeCrAl substrate as a metallic catalytic converter which coated by γ-Al2O3 using ultrasonic and nickelelectroplating technique may improve the exhaust emission control.

  1. Nickel catalyst supported on magnesium and zinc aluminates (MgAl{sub 2}O{sub 4} and ZnAl{sub 2}O{sub 4}) spinels for dry reforming of methane

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, L.C.B. de; Melo, D.M. de A.; Melo, M.A. de F.; Barros, J.M. de F.; Braga, R.M.; Costa, C. de C.; Rodrigues, G., E-mail: ieda.garcia@pq.cnpq.br [Universidade Federal da Paraiba (LACOM/UFPB), Joao Pessoa, PB (Brazil). Dept. de Quimica

    2017-01-15

    Materials such as MgAl{sub 2}O{sub 4} and ZnAl{sub 2}O{sub 4} assessed in the reaction of dry reforming of methane to produce syngas were synthesized by microwave-assisted combustion method using urea as fuel. Samples of synthesized oxides were calcined at 800 °C for 2 h and impregnated with 5% nickel. The impregnated samples were calcined at 850 °C for 4 h to obtain the desired phases. The results of the catalytic tests showed that the catalysts are active for the reaction of dry reforming of methane, and the catalyst that showed the best performance for methane conversion was 5% Ni/MgAl{sub 2}O{sub 4} calcined at 850 °C/4 h. (author)

  2. Colloidal nickel/gallium nanoalloys obtained from organometallic precursors in conventional organic solvents and in ionic liquids: noble-metal-free alkyne semihydrogenation catalysts.

    Science.gov (United States)

    Schütte, Kai; Doddi, Adinarayana; Kroll, Clarissa; Meyer, Hajo; Wiktor, Christian; Gemel, Christian; van Tendeloo, Gustaaf; Fischer, Roland A; Janiak, Christoph

    2014-05-21

    Efforts to replace noble-metal catalysts by low-cost alternatives are of constant interest. The organometallic, non-aqueous wet-chemical synthesis of various hitherto unknown nanocrystalline Ni/Ga intermetallic materials and the use of NiGa for the selective semihydrogenation of alkynes to alkenes are reported. Thermal co-hydrogenolysis of the all-hydrocarbon precursors [Ni(COD)2] (COD = 1,5-cyclooctadiene) and GaCp* (Cp* = pentamethylcyclopentadienyl) in high-boiling organic solvents mesitylene and n-decane in molar ratios of 1 : 1, 2 : 3 and 3 : 1 yields the nano-crystalline powder materials of the over-all compositions NiGa, Ni2Ga3 and Ni3Ga, respectively. Microwave induced co-pyrolysis of the same precursors without additional hydrogen in the ionic liquid [BMIm][BF4] (BMIm = 1-butyl-3-methyl-imidazolium) selectively yields the intermetallic phases NiGa and Ni3Ga from the respective 1 : 1 and 3 : 1 molar ratios of the precursors. The obtained materials are characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), IR, powder X-ray diffraction (PXRD) and atomic absorption spectroscopy (AAS). The single-source precursor [Ni(GaCp*)(PMe3)3] with a fixed Ni : Ga stoichiometry of 1 : 1 was employed as well. In comparison with the co-hydrogenolytic dual precursor source approach it turned out to be less practical due to inefficient nickel incorporation caused by the parasitic formation of stable [Ni(PMe3)4]. The use of ionic liquid [BMIm][BF4] as a non-conventional solvent to control the reaction and stabilize the nanoparticles proved to be particularly advantageous and stable colloids of the nanoalloys NiGa and Ni3Ga were obtained. A phase-selective Ni/Ga colloid synthesis in conventional solvents and in the presence of surfactants such as hexadecylamine (HDA) was not feasible due to the undesired reactivity of HDA with GaCp* leading to inefficient gallium incorporation. Recyclable Ni

  3. Discovery of technical methanation catalysts based on computational screening

    DEFF Research Database (Denmark)

    Sehested, Jens; Larsen, Kasper Emil; Kustov, Arkadii

    2007-01-01

    Methanation is a classical reaction in heterogeneous catalysis and significant effort has been put into improving the industrially preferred nickel-based catalysts. Recently, a computational screening study showed that nickel-iron alloys should be more active than the pure nickel catalyst and at ...

  4. Design of heterogeneous catalysts

    DEFF Research Database (Denmark)

    Frey, Anne Mette

    was inspired by a computational screening, suggesting that alloys such as Ni-Fe, Co-Ni, and Co-Fe should show superior activity to the industrially used nickel catalyst. Especially the Ni-Fe system was considered to be interesting, since such alloy catalysts should be both more active and cheaper than the Ni....... Previously it has been shown that calcination of cobalt catalyst in a NO/He mixture resulted in improved catalytic activity compared to standard air calcined samples, since more homogenous cobalt particles with a narrow particle size distribution were formed. Unfortunately the C5+ selectivity decreased...... well, and the best catalyst prepared had a C5+ yield almost a factor of two higher than a standard air calcined Co catalyst. In the NH3-SCR reaction it is desirable to develop an active and stable catalyst for NOx removal in automotive applications, since the traditionally used vanadium-based catalyst...

  5. Nickel-catalyzed carbocyanation of alkynes

    OpenAIRE

    Nakao, Yoshiaki; Hiyama, Tamejiro

    2008-01-01

    Nickel-catalyzed carbocyanation reaction of alkynes is described. Alkynes undergo aryl- and allylcyanation reaction in the presence of nickel-phosphine catalysts to give a wide range of substituted acrylonitriles in highly stereo-, regio-, and chemoselective manners. Lewis acid cocatalysts, such as AlMe3, AlMe2Cl, and BPh3, are found to promote the arylcyanation significantly. The cooperative catalysis of nickel and Lewis acid also allows the carbocyanation reaction using alkenyl and alkyl cy...

  6. Effect study of the support in nickel and cobalt catalysts for obtaining hydrogen from ethanol steam reforming; Estudo do efeito do suporte em catalisadores de cobalto e niquel para obtencao de hidrogenio a partir da reforma a vapor do etanol

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sirlane Gomes da

    2013-09-01

    A range of oxide-supported metal catalysts have been investigated for the steam reforming of ethanol for the production of hydrogen and subsequent application in fuel cells. The catalysts were synthesized by the co-precipitation and internal gelification methods using cobalt and nickel as active metals supported on aluminum, zirconium, lanthanum and cerium oxides. After prepared and calcined at 550 C Masculine-Ordinal-Indicator the solids were fully characterized by different techniques such as X-rays diffraction(DRX), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy, nitrogen adsorption (B.E.T), temperature-programmed reduction in H2 (TPR-H2) and thermogravimetric analysis. The catalytic tests were performed in a monolithic quartz reactor and submitted to different thermodynamic conditions of steam reforming of ethanol at temperatures varying from 500 Masculine-Ordinal-Indicator C to 800 Masculine-Ordinal-Indicator C. The product gas streams from the reactor were analyzed by an on-line gas chromatograph. The cobalt/nickel catalyst supported on a ceria-lanthania mixture (Co{sub 10%} / Ni{sub 5%} - CeO{sub 2}La{sub 2}O{sub 3}) showed good catalytic performance in hydrogen selectivity reaching a concentration greater than 65%, when compared to other catalytic systems such as: Co{sub 10%} / Ni5% - CeO{sub 2}; Co{sub 10%} / Ni{sub 5%} - CeO{sub 2}ZrO{sub 2}; Co{sub 10%} / Ni{sub 5%} - ZrO{sub 2}; Co{sub 10%} / Ni{sub 5%} - La{sub 2}O{sub 3}; Co{sub 10%} / Ni{sub 5%} - CeO{sub 2}La{sub 2}O{sub 3}/K{sub 2%}; Co{sub 10}% / Ni{sub 5%} - CeO{sub 2}La{sub 2}O{sub 3} / Na{sub 2%}; Ni{sub 10%} / Co{sub 5%} - CeO{sub 2}La{sub 2}O{sub 3}; Co-Al{sub 2}O{sub 3} e Co-Al{sub 2}O{sub 3}CeO{sub 2}. (author)

  7. Fabrication of Crumpled Ball-Like Nickel Doped Palladium-Iron Oxide Hybrid Nanoparticles with Controlled Morphology as Effective Catalyst for Suzuki–Miyaura Coupling Reaction

    OpenAIRE

    Seongwan Jang; Taewoo Kim; Kang Hyun Park

    2017-01-01

    We report a facile synthetic strategy for nickel-doped palladium-iron oxide hybrid nanoparticles with controllable morphology. In this synthetic method, the morphology of the nanoparticles was regulated by the amount of triphenylphosphine used. When 1 mmol of triphenylphosphine was used as a capping agent, the main morphology of the nanoparticles was crumpled balls composed of nanosheets with an average particle size of 215 nm. The nanoparticles showed higher catalytic activity in the Suzuki–...

  8. Highly efficient bimetal synergetic catalysis by a multi-wall carbon nanotube supported palladium and nickel catalyst for the hydrogen storage of magnesium hydride.

    Science.gov (United States)

    Yuan, Jianguang; Zhu, Yunfeng; Li, Liquan

    2014-06-25

    A multi-wall carbon nanotube supported Pd and Ni catalyst efficiently catalyzes the hydrogen storage of magnesium hydride prepared by HCS + MM. Excellent hydrogen storage properties were obtained: hydrogen absorption - 6.44 wt% within 100 s at 373 K, hydrogen desorption - 6.41 wt% within 1800 s at 523 K and 6.70 wt% within 400 s at 573 K.

  9. Effects of Gold Substrates on the Intrinsic and Extrinsic Activity of High-Loading Nickel-Based Oxyhydroxide Oxygen Evolution Catalysts

    DEFF Research Database (Denmark)

    Chakthranont, Pongkarn; Kibsgaard, Jakob; Gallo, Alessandro

    2017-01-01

    We systematically investigate the effects of Au substrates on the oxygen evolution activities of cathodically electrodeposited nickel oxyhydroxide (NiOOH), nickel–iron oxyhydroxide (NiFeOOH), and nickel–cerium oxyhydroxide (NiCeOOH) at varying loadings from 0 to 2000 nmol of metal/cm2. We determi...... high geometric current densities on flat substrates. By investigating the mass and site specific activities as a function of loading, we bridge the practical geometric activity to the fundamental intrinsic activity....

  10. Highly selective biaryl cross-coupling reactions between aryl halides and aryl Grignard reagents: a new catalyst combination of N-heterocyclic carbenes and iron, cobalt, and nickel fluorides.

    Science.gov (United States)

    Hatakeyama, Takuji; Hashimoto, Sigma; Ishizuka, Kentaro; Nakamura, Masaharu

    2009-08-26

    Combinations of N-heterocyclic carbenes (NHCs) and fluoride salts of the iron-group metals (Fe, Co, and Ni) have been shown to be excellent catalysts for the cross-coupling reactions of aryl Grignard reagents (Ar(1)MgBr) with aryl and heteroaryl halides (Ar(2)X) to give unsymmetrical biaryls (Ar(1)-Ar(2)). Iron fluorides in combination with SIPr, a saturated NHC ligand, catalyze the biaryl cross-coupling between various aryl chlorides and aryl Grignard reagents in high yield and high selectivity. On the other hand, cobalt and nickel fluorides in combination with IPr, an unsaturated NHC ligand, exhibit interesting complementary reactivity in the coupling of aryl bromides or iodides; in contrast, with these substrates the iron catalysts show a lower selectivity. The formation of homocoupling byproducts is suppressed markedly to less than 5% in most cases by choosing the appropriate metal fluoride/NHC combination. The present catalyst combinations offer several synthetic advantages over existing methods: practical synthesis of a broad range of unsymmetrical biaryls without the use of palladium catalysts and phosphine ligands. On the basis of stoichiometric control experiments and theoretical studies, the origin of the unique catalytic effect of the fluoride counterion can be ascribed to the formation of a higher-valent heteroleptic metalate [Ar(1)MF(2)]MgBr as the key intermediate in our proposed catalytic cycle. First, stoichiometric control experiments revealed the stark differences in chemical reactivity between the metal fluorides and metal chlorides. Second, DFT calculations indicate that the initial reduction of di- or trivalent metal fluoride in the wake of transmetalation with PhMgCl is energetically unfavorable and that formation of a divalent heteroleptic metalate complex, [PhMF(2)]MgCl (M = Fe, Co, Ni), is dominant in the metal fluoride system. The heteroleptic ate-complex serves as a key reactive intermediate, which undergoes oxidative addition with Ph

  11. Marché des catalyseurs d'hydrogénation des corps gras Market of Hydrogenation Catalysts for Fats and Derivatives

    Directory of Open Access Journals (Sweden)

    Barraque M.

    2006-11-01

    (production d'alcools gras. Les chiffres d'affaires pour ces 3 catalyseurs sont respectivement égaux à 50,1, 0,5 et 11 millions de dollars/an. Since Institut Français du Pétrole (IFP has a great deal of experience in the field of catalysts, particularly for hydrogenation, the Evaluation Department has made studies at various times to evaluate the potential markets. The analysis making up this article was made to determine the possible outlets for catalysts used for the hydrogenation of fats and oils. It covers the food industry, the hydrogenation of fatty acids of animal or vegetable origin, and the production of fatty alcohols and fatty amines. This market is over $60 million per year and corresponds to nearly 11,000 t/year of catalysts used. These figures include captive consumptions of catalysts produced by companies using them. This business turnover is about the same as the one for hydrogenation catalysts used for the synthesis of the major building-block petrochemicals. More than 64% of the applications have to do with the food industry, i. e. production of margarine and shortening, hydrogenation of salad oils and deep-frying oils in the United States. Whereas the consumption of catalysts used in lipochemistry is highly concentrated in the main industrialized regions (United States, Western Europe, Japan, that of the food industry is much more scattered. The three regions mentioned above account for less than 64% of world consumption. Estimated outlets represent annual business turnovers of $41 million for the food industry, $8. 3 million for the production of fatty acids, $11 million for the production of fatty alcohols, and $1. 3 million for the production of fatty amines. These hydrogenations are performed in the presence of supported nickel (food industry, production of fatty acids and secondary and tertiary amines or in the presence of Raney nickel (production of primary amines or, copper chromite (production of, fatty alcohols. The business turnovers for these

  12. Study of preparation method and oxidization/reduction effect on the performance of nickel-cerium oxide catalysts for aqueous-phase reforming of ethanol

    Science.gov (United States)

    Roy, B.; Leclerc, C. A.

    2015-12-01

    The effect of preparation method and oxidation state of the active metal on the catalytic activity of Ni-Ce-O catalysts was studied for aqueous phase reforming of ethanol. A sol-gel (SG) route and a solution combustion synthesis (SCS) method were used for the preparation of 10 wt% Ni loaded catalysts. The catalytic activity of three groups of catalysts; reduced at 425 °C (HR, metallic Ni), reduced at 1000 °C (FR, metallic Ni), and not reduced (NR, as NiO) were tested at different operating conditions. The difference in the metal particle sizes, governed by the preparation method, affects the catalytic efficiency most, not the reduced or oxidized state of Ni. The SG samples were superior for ethanol conversion and selectivity for H2 and CO2 compared to the SCS samples. The X-ray photoelectron spectroscopy (XPS) analysis of the samples demonstrated that the relative ratio of Ce2O3 to CeO2 increased inside the reactor. While Ni doping increases oxygen mobility in the Ce-O lattice, Ce3+ converts Ni2+ to metallic Ni inside the reactor. This can explain why the reduction stage for Ni-Ce-O system in APR is irrelevant. Higher oxygen mobility through the support helps oxidation of CO to CO2 leading to improved catalytic performance.

  13. Regeneration of Hydrotreating and FCC Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    CM Wai; JG Frye; JL Fulton; LE Bowman; LJ Silva; MA Gerber

    1999-09-30

    Hydrotreating, hydrocracking, and fluid catalytic cracking (FCC) catalysts are important components of petroleum refining processes. Hydrotreating and hydrocracking catalysts are used to improve the yield of high-quality light oil fractions from heavier crude oil and petroleum feedstocks containing high levels of impurities. FCC catalysts improve the yield of higher octane gasoline from crude oil. Residuum hydrotreating and cracking catalysts are susceptible to irreversible deactivation caused by adsorption of sulfur and by metals impurities, such as vanadium and nickel. The gradual buildup of these impurities in a hydrotreating catalyst eventually plugs the pores and deactivates it. Nickel and vanadium adversely affect the behavior of cracking catalysts, reducing product yield and quality. Replacing deactivated catalysts represents a significant cost in petroleum refining. Equally important are the costs and potential liabilities associated with treating and disposing spent catalysts. For example, recent US Environmental Protection Agency rulings have listed spent hydrotreating and hydrorefining catalysts as hazardous wastes. FCC catalysts, though more easily disposed of as road-base or as filler in asphalt and cement, are still an economic concern mainly because of the large volumes of spent catalysts generated. New processes are being considered to increase the useful life of catalysts or for meeting more stringent disposal requirements for spent catalysts containing metals. This report discusses a collaborative effort between Pacific Northwest National Laboratory (PNNL) and Phillips Petroleum, Inc., to identify promising chemical processes for removing metals adhered to spent hydrodesulfurization (HDS, a type of hydrotreating catalyst) and FCC catalysts. This study, conducted by PNNL, was funded by the US Department of Energy's Bartlesville Project Office. Fresh and spent catalysts were provided by Phillips Petroleum. The FCC catalyst was a rare

  14. Nickel oxide/carbon nanotube/polyaniline nanocomposite as bifunctional anode catalyst for high-performance Shewanella-based dual-chamber microbial fuel cell.

    Science.gov (United States)

    Nourbakhsh, Fatemeh; Mohsennia, Mohsen; Pazouki, Mohammad

    2017-11-01

    A novel nickel oxide/carbon nanotube/polyaniline (NCP) nanocomposite has been prepared and used to modify the electrocatalytic properties of carbon cloth anode in fabricating dual-chamber MFC. The prepared nanocomposite was characterized by scanning electron microscopy, X-ray diffraction, and fourier transform infrared spectroscopy. The carbon cloth coated with the NCP nanocomposite showed the enhanced electrochemical performance as compared to bare carbon cloth anode. The electrochemical properties of the fabricated MFC with the modified anode have been investigated by linear sweep voltammetry and electrochemical impedance spectroscopy. The maximum power density of the MFC using the novel NCP nanocomposite-carbon cloth anode increased by 61.88% compared to that of the bare carbon cloth anode. In comparison to the bare carbon cloth anode, the new composite anode showed 26.8% enhancement of current density output which it can be due to the enhancement of the charge transfer capability.

  15. Catalyst in Basic Oleochemicals

    Directory of Open Access Journals (Sweden)

    Eva Suyenty

    2007-10-01

    Full Text Available Currently Indonesia is the world largest palm oil producer with production volume reaching 16 million tones per annum. The high crude oil and ethylene prices in the last 3 – 4 years contribute to the healthy demand growth for basic oleochemicals: fatty acids and fatty alcohols. Oleochemicals are starting to replace crude oil derived products in various applications. As widely practiced in petrochemical industry, catalyst plays a very important role in the production of basic oleochemicals. Catalytic reactions are abound in the production of oleochemicals: Nickel based catalysts are used in the hydrogenation of unsaturated fatty acids; sodium methylate catalyst in the transesterification of triglycerides; sulfonic based polystyrene resin catalyst in esterification of fatty acids; and copper chromite/copper zinc catalyst in the high pressure hydrogenation of methyl esters or fatty acids to produce fatty alcohols. To maintain long catalyst life, it is crucial to ensure the absence of catalyst poisons and inhibitors in the feed. The preparation methods of nickel and copper chromite catalysts are as follows: precipitation, filtration, drying, and calcinations. Sodium methylate is derived from direct reaction of sodium metal and methanol under inert gas. The sulfonic based polystyrene resin is derived from sulfonation of polystyrene crosslinked with di-vinyl-benzene. © 2007 BCREC UNDIP. All rights reserved.[Presented at Symposium and Congress of MKICS 2007, 18-19 April 2007, Semarang, Indonesia][How to Cite: E. Suyenty, H. Sentosa, M. Agustine, S. Anwar, A. Lie, E. Sutanto. (2007. Catalyst in Basic Oleochemicals. Bulletin of Chemical Reaction Engineering and Catalysis, 2 (2-3: 22-31.  doi:10.9767/bcrec.2.2-3.6.22-31][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.2.2-3.6.22-31 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/6

  16. Formation of hydrocarbon compounds during the hydrocracking of non-edible vegetable oils with cobalt-nickel supported on hierarchical HZSM-5 catalyst

    Science.gov (United States)

    Marlinda, L.; Al-Muttaqii, M.; Roesyadi, A.; Prajitno, D. H.

    2017-05-01

    The hierarchical Co-Ni/HZSM-5 catalyst with hierarchical pore structure was prepared by desilication and incipient wetness impregnation. Hydrocracking of non-edible vegetable oils at temperature of 400 °C, 20±5 bar for 2 h was performed in the presence of this type of catalyst under hydrogen initial pressure in pressured batch reactor. Non-edible vegetable oils, such as Reutealis trisperma (Blanco) airy shaw (sunan candlenut) and Hevea brasiliensis (rubber seed) were chosen to study the effect of the degree of saturation and lateral chain length on hydrocarbon compounds obtained through hydrocracking. Cerbera manghas oil was also tested for comparison because the composition of fatty acid was different with the other oils The hydrocracking test indicated that liquid product produced has a similar hydrocarbon compounds with petroleum diesel. The most abundant hydrocarbon is pentadecane (n-C15) and heptadecane (n-C17). The high aromatic compounds were found in liquid product produced in hydrocracking of Sunan candlenut oil.

  17. Novel Anode Catalyst for Direct Methanol Fuel Cells

    OpenAIRE

    Basri, S.; Kamarudin, S. K.; Daud, W. R. W.; Yaakob, Z.; Kadhum, A. A. H.

    2014-01-01

    PtRu catalyst is a promising anodic catalyst for direct methanol fuel cells (DMFCs) but the slow reaction kinetics reduce the performance of DMFCs. Therefore, this study attempts to improve the performance of PtRu catalysts by adding nickel (Ni) and iron (Fe). Multiwalled carbon nanotubes (MWCNTs) are used to increase the active area of the catalyst and to improve the catalyst performance. Electrochemical analysis techniques, such as energy dispersive X-ray spectrometry (EDX), X-ray diffracti...

  18. Production Hydrogen and Nanocarbon Via Methane Decomposition Using Ni-based Catalysts. Effect of Acidity and Catalyst Diameter

    OpenAIRE

    Widodo W. Purwanto; M Nasikin; E Saputra; Song, L.

    2005-01-01

    Objectives of this research are mainly to study impacts of acidity strength (by varying amount of precipitant and loadingAl-Si) and the effect of nickel particle size (by varying calcinations temperature) on decomposition reactionperformances. In this research, high-nickel-loaded catalyst is prepared with two methods. Ni-Cu/Al catalysts wereprepared with co-precipitation method. While the Ni-Cu/Al-Si catalyst were prepared by combined co-precipitation andsol-gel method. The direct cracking of...

  19. TEORES DE DIMETIL SULFETO ESTIMADOS PELO MÉTODO NÍQUEL-RANEY E ACEITABILIDADE DE AMOSTRAS DE CACHAÇA Dimethyl sulfide contents estimated by Ni-Raney method and “cachaça” samples acceptability.

    Directory of Open Access Journals (Sweden)

    J. F. A. TOLEDO

    2008-08-01

    Full Text Available

    O defeito sensorial das aguardentes de cana destiladas na ausência de cobre já foi relacionado com a presença do dimetil sulfeto (DMS, o que revela a importância de identificar os teores deste composto eventualmente presente nesta bebida. Considerando-se, porém, o custo relativamente elevado dos métodos de cromatografia de fase gasosa até agora utilizados na determinação do DMS, foi objetivo deste trabalho avaliar a possível utilização do método de Níquel-Raney como forma de controlar o referido defeito. Nesse sentido foi estudada a relação entre os teores de DMS estimados pelo método proposto, com sua influência sensorial avaliada através de testes de aceitação. Os resultados obtidos permitiram concluir que mesmo em concentrações abaixo de 5mg/L, os testes sensoriais revelam haver alta correlação entre os teores de DMS, determinados pelo método de Níquel-Raney com a diminuição da qualidade sensorial das amostras avaliadas. Os resultados obtidos permitem propor o método de Níquel-Raney como uma opção válida no controle da presença de DMS na cachaça e assim, prevenir efeitos negativos na qualidade sensorial do produto final.

    The sensory defect of “cachaça”, when distilled in absence of copper, had been already related to dimethyl sulphide levels, pointing out the importance to control its contents in this beverage. Considering the relatively higher costs of the gas-chromatography techniques, the aim of this work was to evaluate the possible use of the Níquel-Raney method, to control the dimethyl sulphide contents. In this way, the dimethyl sulphide contents (estimated by Níquel-Raney method and its sensory deffect evaluated by acceptability sensory tests, were compared. The results showed that

  20. REMOVAL OF NICKEL(II) AND PALLADIUM(II) FROM SURFACE ...

    African Journals Online (AJOL)

    Preferred Customer

    welding, in pigments for paint, in ceramics, in surgical and dental prostheses, in magnetic tapes and computer components and in nickel catalysts. Nickel enters waters from dissolution of rocks and soils, from biological cycles, from atmospheric fallout, especially from industrial processes and waste disposal [1]. Nickel was ...

  1. Energetic Mapping of Ni Catalysts by Detailed Kinetic Modeling

    DEFF Research Database (Denmark)

    Bjørgum, Erlend; Chen, De; Bakken, Mari G.

    2005-01-01

    Temperature-programmed desorption (TPD) of CO has been performed on supported and unsupported nickel catalysts. The unsupported Ni catalyst consists of a Ni(14 13 13) single crystal which has been studied under ultrahigh vacuum conditions. The desorption energy for CO at low CO surface coverage w...... nicely with literature values, providing useful information for identifying active sites on supported Ni catalysts....

  2. Nickel allergy

    DEFF Research Database (Denmark)

    Fischer, L A; Johansen, J D; Menné, T

    2007-01-01

    BACKGROUND: The frequency of nickel allergy varies between different population groups. Exposure regulation has proven effective in decreasing the frequency. Experimental studies with other allergens have shown a significant relation between patch test reactivity and repeated open application test...... in a patch test and a dilution series of three concentrations in a ROAT, with duration of up to 21 days. Eighteen persons with no nickel allergy were included as control group for the ROAT. RESULTS: The predicted dose which will elicit a reaction in 10% of allergic individuals was calculated to be 0......-response; indeed, there was no statistically significant difference. CONCLUSIONS: For elicitation of nickel allergy the elicitation threshold for the patch test is higher than the elicitation threshold (per application) for the ROAT, but is approximately the same as the accumulated elicitation threshold...

  3. Characterization of Thioether-Linked Protein Adducts of DNA Using a Raney-Ni Mediated Desulfurization Method and Liquid Chromatography-Electrospray-Tandem Mass Spectrometry

    Science.gov (United States)

    Chowdhury, Goutam; Guengerich, F. Peter

    2015-01-01

    This unit contains a complete procedure for the detection and structural characterization of DNA protein crosslinks (DPCs). The procedure also describes an approach for the quantitation of the various structurally distinct DPCs. Although various methods have been described in the literature for labile DPCs, characterization of non-labile adducts remain a challenge. Here we present a novel approach for characterization of both labile and non-labile adducts by the use of a combination of chemical, enzymatic, and mass spectrometric approaches. A Raney Ni-catalyzed reductive desulfurization method was used for removal of the bulky peptide adducts, enzymatic digestion was used to digest the protein to smaller peptides and DNA to nucleosides, and finally LC-ESI-tandem mass spectrometry (MS) was utilized for detection and characterization of nucleoside adducts. PMID:25754888

  4. Oxidation catalyst

    Science.gov (United States)

    Ceyer, Sylvia T.; Lahr, David L.

    2010-11-09

    The present invention generally relates to catalyst systems and methods for oxidation of carbon monoxide. The invention involves catalyst compositions which may be advantageously altered by, for example, modification of the catalyst surface to enhance catalyst performance. Catalyst systems of the present invention may be capable of performing the oxidation of carbon monoxide at relatively lower temperatures (e.g., 200 K and below) and at relatively higher reaction rates than known catalysts. Additionally, catalyst systems disclosed herein may be substantially lower in cost than current commercial catalysts. Such catalyst systems may be useful in, for example, catalytic converters, fuel cells, sensors, and the like.

  5. Nickel embedded in N-doped porous carbon for the hydrogenation of nitrobenzene to p-aminophenol in sulphuric acid.

    Science.gov (United States)

    Wang, Tao; Dong, Zhen; Fu, Teng; Zhao, Yanchao; Wang, Tian; Wang, Yongzheng; Chen, Yi; Han, Baohang; Ding, Weiping

    2015-12-28

    An acid-resistant catalyst composed of nickel embedded in N-doped porous carbon is developed for the catalytic hydrogenation of nitrobenzene (NB) to p-aminophenol (PAP). The catalyst, due to a special electron donation from nickel to the N-doped porous carbon, shows an excellent catalytic performance and stability in sulphuric acid solution.

  6. Rota hidrometalúrgica de recuperação de molibdênio, cobalto, níquel e alumínio de catalisadores gastos de hidrotratamento em meio ácido Hydrometallurgical route to recover molybdenum, nickel, cobalt and aluminum from spent hydrotreating catalysts in acid medium

    Directory of Open Access Journals (Sweden)

    Ivam Macedo Valverde Júnior

    2008-01-01

    Full Text Available This work describes a hydrometallurgical route for processing spent commercial catalysts (CoMo and NiMo/Al2O3. Samples were preoxidized (500 ºC, 5 h in order to eliminate coke and other volatile species present. The calcined solid was dissolved in concentrated H2SO4 and water (1:1 vol/vol at 90 ºC; the insoluble matter was separated from the solution. Molybdenum was recovered by solvent extraction using tertiary amines at pH around 1.8. Cobalt (or nickel was separated by addition of aqueous ammonium oxalate at the above pH. Phosphorus was removed by passing the liquid through a strong anion exchange column. Aluminum was recovered by neutralizing the solution with NaOH. The route presented in this work generates less final aqueous wastes because it is not necessary to use alkaline medium during the metal recovery steps.

  7. Chemical nature of catalysts of oxide nanoparticles in environment ...

    Indian Academy of Sciences (India)

    Carbon nanostructures (CNS) are often grown using oxide nanoparticles as catalyst in chemical vapour deposition and these oxides are not expected to survive as such during growth. In the present study, the catalysts of cobalt- and nickel oxide-based nanoparticles of sizes varying over a range have been reduced at 575 ...

  8. SHS-produced intermetallides as catalysts for hydrocarbons synthesis from CO and H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, O.L.; Kazantsev, R.V.; Davydov, P.E.; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry; Borshch, V.N.; Pugacheva, E.V. [Russian Academy of Sciences, Chernogolovka (Russian Federation). Inst. of Structural Macrokinetics and Materials Science

    2012-07-01

    Raney-type polymetallic alloys were prepared by Self-Propagating High-Temperature Synthesis followed by alkaline treating. Surface morphology and composition of were studied using XRD, BET, SEM and EMPA techniques. The samples were tested in Fischer-Tropsch synthesis demonstrated rather high activity and very high selectivity to heavy paraffins. High selectivity to C{sub 5+} hydrocarbons is attributed to high thermal conductivity of alloys which prevents hot spots formation and therefore suppresses formation of methane and light hydrocarbons. Selectivity can be further improved by adding some d-metals in catalyst composition. Promotion with La seems to be particularly suitable for lowering methane formation while doping with Ni enhances methane yield greatly. (orig.)

  9. Nickel Decorated on Phosphorous-Doped Carbon Nitride as an Efficient Photocatalyst for Reduction of Nitrobenzenes

    National Research Council Canada - National Science Library

    Anurag Kumar; Pawan Kumar; Chetan Joshi; Manvi Manchanda; Rabah Boukherroub; Suman L Jain

    2016-01-01

      Nickel nanoparticle-decorated phosphorous-doped graphitic carbon nitride (Ni@g-PC3N4) was synthesized and used as an efficient photoactive catalyst for the reduction of various nitrobenzenes under visible light irradiation...

  10. Thermocatalytic decomposition of methane/methanol mixture for hydrogen production: Effect of nickel loadings on alumina support

    Science.gov (United States)

    Awad, Ali; Salam, Abdus; Abdullah, Bawadi

    2017-10-01

    Hydrogen produced by thermocatalytic decomposition of methane is termed as clean and alternative fuel however high reaction temperature and fast catalyst deactivation limitize the efficiency of this process. In this study nickel based catalyst supported on alumina with various Ni loadings were prepared by impregnation method and employed for TCD of methane/methanol mixture for hydrogen production. Surface area and pore volume were decreased by increasing the amount of nickel loading on alumina. The results revealed that both reaction temperature and nickel loading affected the reaction rates and catalyst deactivation time. Scanning electron microscope (SEM) and Thermogravematric analysis (TGA) were used for characterization of fresh and spent catalyst. Crystalline carbon was formed on the surface of the catalyst and was proved by TGA analysis. Methane yield increased as the reaction temperature was increased but the catalyst deactivation time was decreased as a lot carbon was encapsulated on the surface of the catalyst.

  11. Wafer scale integration of catalyst dots into nonplanar microsystems

    DEFF Research Database (Denmark)

    Gjerde, Kjetil; Kjelstrup-Hansen, Jakob; Gammelgaard, Lauge

    2007-01-01

    In order to successfully integrate bottom-up fabricated nanostructures such as carbon nanotubes or silicon, germanium, or III-V nanowires into microelectromechanical systems on a wafer scale, reliable ways of integrating catalyst dots are needed. Here, four methods for integrating sub-100-nm...... diameter nickel catalyst dots on a wafer scale are presented and compared. Three of the methods are based on a p-Si layer utilized as an in situ mask, an encapsulating layer, and a sacrificial window mask, respectively. All methods enable precise positioning of nickel catalyst dots at the end...

  12. Elastic and piezoresistive properties of nickel carbides from first principles

    Science.gov (United States)

    Kelling, Jeffrey; Zahn, Peter; Schuster, Jörg; Gemming, Sibylle

    2017-01-01

    The nickel-carbon system has received increased attention over the past years due to the relevance of nickel as a catalyst for carbon nanotube and graphene growth, where nickel carbide intermediates may be involved or carbide interface layers form in the end. Nickel-carbon composite thin films comprising Ni3C are especially interesting in mechanical sensing applications. Due to the metastability of nickel carbides, formation conditions and the coupling between mechanical and electrical properties are not yet well understood. Using first-principles electronic structure methods, we calculated the elastic properties of Ni3C ,Ni2C , and NiC , as well as changes in electronic properties under mechanical strain. We observe that the electronic density of states around the Fermi level does not change under the considered strains of up to 1%, which correspond to stresses up to 3 GPa . Relative changes in conductivity of Ni3C range up to maximum values of about 10%.

  13. RESOURCES-ECONOMY TECHNOLOGY OF CASTINGS PRODUCTION OF NICKEL-CONTAINING CAST-IRONS

    Directory of Open Access Journals (Sweden)

    O. S. Komarov

    2008-01-01

    Full Text Available The technological process of the cast-iron IChH28H2 alloying by means of insertion into burden composition of briquettes of dead nickel-chromic catalysts is developed. This technology allows to carry out recycling of expensive metals such as nickel, and in that way to decrease the cost price of castings. 

  14. Waste catalysts for waste polymer.

    Science.gov (United States)

    Salmiaton, A; Garforth, A

    2007-01-01

    Catalytic cracking of high-density polyethylene (HDPE) over fluid catalytic cracking (FCC) catalysts (1:6 ratio) was carried out using a laboratory fluidized bed reactor operating at 450 degrees C. Two fresh and two steam deactivated commercial FCC catalysts with different levels of rare earth oxide (REO) were compared as well as two used FCC catalysts (E-Cats) with different levels of metal poisoning. Also, inert microspheres (MS3) were used as a fluidizing agent to compare with thermal cracking process at BP pilot plant at Grangemouth, Scotland, which used sand as its fluidizing agent. The results of HDPE degradation in terms of yield of volatile hydrocarbon product are fresh FCC catalysts>steamed FCC catalysts approximately used FCC catalysts. The thermal cracking process using MS3 showed that at 450 degrees C, the product distribution gave 46 wt% wax, 14% hydrocarbon gases, 8% gasoline, 0.1% coke and 32% nonvolatile product. In general, the product yields from HDPE cracking showed that the level of metal contamination (nickel and vanadium) did not affect the product stream generated from polymer cracking. This study gives promising results as an alternative technique for the cracking and recycling of polymer waste.

  15. A novel, effective and low cost catalyst for methanol oxidation based on nickel ions dispersed onto poly(o-toluidine)/Triton X-100 film at the surface of multi-walled carbon nanotube paste electrode

    Energy Technology Data Exchange (ETDEWEB)

    Raoof, Jahan-Bakhsh; Ojani, Reza; Hosseini, Sayed Reza [Electroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, Mazandaran University, Postal Code 47416-95447, Babolsar (Iran, Islamic Republic of)

    2011-02-15

    In this work, for the first time an aqueous solution of Triton X-100 (TX-100) [t-octyl phenoxy polyethoxy ethanol] non-ionic surfactant is used as an additive for electropolymerization of o-toluidine (OT) onto multi-walled carbon nanotube paste electrode (CNTPE), which is investigated as a novel matrix for dispersion of nickel ions. The growth of polymeric film in the absence of TX-100 is poor, while it considerably increases in the presence of the surfactant and its growth is continued up to 60th cycle. The as-prepared substrate is used as porous matrix for dispersion of transition metal ions of Ni(II) to POT/TX-100 film by immersing the modified electrode in a 0.1 M nickel sulfate solution. The electrochemical characterization of this modified electrode exhibits redox behavior of Ni(III)/Ni(II) couple. It has been shown that POT/TX-100 at the surface of CNTPE improves catalytic efficiency of the dispersed nickel ions toward methanol oxidation. Then, using a chronoamperometric method, the catalytic rate constant, k, for methanol oxidation is found to be 7.40 x 10{sup 4} cm{sup 3} mol{sup -1} s{sup -1}. At the end of this work, long-term stability of this modified electrode has been investigated. (author)

  16. Effect of the nickel precursor on the impregnation and drying of γ-Al2O3 catalyst bodies: a UV-vis and IR micro-spectroscopic study

    NARCIS (Netherlands)

    Espinosa Alonso, L.; de Jong, K.P.; Weckhuysen, B.M.

    2008-01-01

    The elemental preparation steps of impregnation and drying of Ni/g-Al2O3 catalyst bodies have been studied by combining UV-vis and IR microspectroscopy. The influence of the number of chelating ligands in [Ni(en)x(H2O)6-2x]2+ precursor complexes (with en ) ethylenediamine and x ) 0-3) has been

  17. Support acidity influence in NiMoS (Nickel and Molybdenum) catalyst for Marlim diesel; Influencia da acidez do suport de catalisadores NiMoS (Niquel e Molibidenio) no hidrotratamento de diesel Marlim

    Energy Technology Data Exchange (ETDEWEB)

    Ferraz, Sheila Guimaraes de Almeida; Zotin, Jose Luiz; Jesus, Anderson Gomes de; Santos, Bruno Martins; Medeiros, Marcus Vinicius Costa [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    The specification of diesel points to the reduction of the sulfur content, of the final boiling point, of the density range and increase of the cetane number. These two last properties are directly related with the ability of the hydrotreating catalytic system in promoting the hydrogenation of aromatic structures and ring opening of the naphthenic compounds, which are both associated to low cetane number. In such way, more acidic catalysts, able to promote the cracking of naphthenic structures, should be evaluated for the diesel HDT. Three bifunctional NiMo catalysts with the same metal content, different acidity and similar active phase dispersion were prepared using alumina, silica-alumina and alumina-Y zeolite as supports. These catalysts were evaluated in a micro-reactor unit for diesel HDT aiming to correlate their activity with the support acidity. The alumina and alumina-zeolite supported catalysts presented better performance than the one supported on silica-alumina. NiMo/alumina-zeolite showed higher cetane and density improvement, associated with a slight decrease in the initial boiling point. (author)

  18. Nickel N-heterocyclic carbene complexes in homogeneous catalysis

    NARCIS (Netherlands)

    Berding, Joris

    2009-01-01

    Described in this thesis are the investigations into the chemistry of N-heterocyclic carbene (NHC) ligands and transition-metal complexes thereof. Specifically, a variety of N-heterocyclic carbene complexes of nickel were prepared, characterized and used as catalysts in three types of homogeneous

  19. Synthesis, characterization and crystal structure of new nickel ...

    Indian Academy of Sciences (India)

    tion of hydrocarbons and as precursors in the synthesis of hydrodesulfurization catalyst,10 sensors,11 scintilla- tor materials,12 and for their electrochemical,13 and photoluminescence14 properties. The molybdate material, NiMoO4 was applied for alkane dehydrogenation.15 Three different phases of nickel molybdate can ...

  20. Ni Catalysts Supported on Modified Alumina for Diesel Steam Reforming

    Directory of Open Access Journals (Sweden)

    Antonios Tribalis

    2016-01-01

    Full Text Available Nickel catalysts are the most popular for steam reforming, however, they have a number of drawbacks, such as high propensity toward coke formation and intolerance to sulfur. In an effort to improve their behavior, a series of Ni-catalysts supported on pure and La-, Ba-, (La+Ba- and Ce-doped γ-alumina has been prepared. The doped supports and the catalysts have been extensively characterized. The catalysts performance was evaluated for steam reforming of n-hexadecane pure or doped with dibenzothiophene as surrogate for sulphur-free or commercial diesel, respectively. The undoped catalyst lost its activity after 1.5 h on stream. Doping of the support with La improved the initial catalyst activity. However, this catalyst was completely deactivated after 2 h on stream. Doping with Ba or La+Ba improved the stability of the catalysts. This improvement is attributed to the increase of the dispersion of the nickel phase, the decrease of the support acidity and the increase of Ni-phase reducibility. The best catalyst of the series doped with La+Ba proved to be sulphur tolerant and stable for more than 160 h on stream. Doping of the support with Ce also improved the catalytic performance of the corresponding catalyst, but more work is needed to explain this behavior.

  1. Carbon coated nickel nanoparticles produced in high-frequency arc plasma at ambient pressure

    Science.gov (United States)

    Vnukova, Natalia; Dudnik, Alexander; Komogortsev, Sergey; Velikanov, Dmitry; Nemtsev, Ivan; Volochaev, Michael; Osipova, Irina; Churilov, Grigory

    2017-10-01

    The nickel particles with the mean size about 10-20 nm coated with carbon were extracted by the treatment of the carbon condensate with nitric and hydrochloric acids. The initial carbon condensate containing nickel nanoparticles with a graphite conversion was synthesized in the high-frequency carbon-helium arc plasma at ambient pressure with the nickel nanoparticles as a catalyst. The nickel content in the nanoparticles was 84.6 wt%. Magnetic properties of the nanoparticles are characterized by the high hysteresis and thermal stability. The sample of compacted nanoparticles is characterized by electrical resistance much higher than it in of compacted initial condensate.

  2. Dates in the development of catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Simon

    1943-05-20

    A chronological listing is presented of the dates on which various I. G. Farbenindustrie catalysts were first used. In most cases the entries gave compositions and some hints at the methods of preparation of the catalysts as well as the code numbers for the catalysts. The listing started in December, 1924, and extended throught August, 1941. Some of the more important catalysts were the following: 5058, tungsten disulfide (WS/sub 2/), produced from the thio salt by dry decomposition (1930); 6434, a diluted mixture of hydrogen fluoride-treated ''Terrana'' and 10% WS/sub 2/ (1935); 6719, a prehydrogenation catalyst of 75 parts ferrous sulfide (FeS), 22 parts WS/sub 2/, and 3 parts nickel monosulfide (NiS) (1937); 7019, an aromatization catalyst of 100 parts primry coal, 15 parts chromic oxide (Cr/sub 2/O/sub 3/), and 5 parts vanadium sesquioxide (V/sub 2/O/sub 3/) (1938); 7360, a DHD catalyst of activated alumina (Al/sub 2/O/sub 3/) and 55 g/l molybdenum trioxide (MoO/sub 3/) (1939); 7846, a prehydrogenated catalyst, a sulfonated mixture of activated alumina, 100 g/l MoO/sub 3/, and 30 g/l nickel sesquioxide (Ni/sub 2/O/sub 3/) (1940); and 8376 W, a prehydrogenation catalyst, a sulfonated mixture of activated alumina, 250 g/l tungsten trioxide (WO/sub 3/), and 50 g/l Ni/sub 2/O/sub 3/ (1941). Other caalysts given included numbers 1724, 2365, 2473, 2500, 3510, 3884, 5053, 5676, 6525, and 6561. Compounds used other than those mentioned above included molybdenum disulfide (MoS/sub 2/), zinc sulfide (ZnS), zinc oxide (ZnO), and magnesium oxide (MgO).

  3. Mononuclear Nickel(II Complexes with Schiff Base Ligands: Synthesis, Characterization, and Catalytic Activity in Norbornene Polymerization

    Directory of Open Access Journals (Sweden)

    Yi-Mei Xu

    2017-03-01

    Full Text Available The nickel(II catalyst has manifested higher catalytic activity compared to that of other late transition metal catalysts for norbornene polymerization. Therefore, several structurally similar trans-nickel(II compounds of N,O-chelate bidentate ligands were synthesized and characterized. Both the electronic effect and the steric hindrance influence polymerization. The molecular structures of 2, 4 and 5 were further confirmed by single-crystal X-ray diffraction.

  4. Hydrogenation of citral into its derivatives using heterogeneous catalyst

    Science.gov (United States)

    Sudiyarmanto, Hidayati, Luthfiana Nurul; Kristiani, Anis; Aulia, Fauzan

    2017-11-01

    Citral as known as a monoterpene can be found in plants and citrus fruits. The hydrogenation of citral into its derivatives become interesting area for scientist. This compound and its derivatives can be used for many application in pharmaceuticals and food areas. The development of heterogeneous catalysts become an important aspect in catalytic hydrogenation citral process. Nickel supported catalysts are well known as hydrogenation catalyst. These heterogeneous catalysts were tested their catalytic activity in hydrogenation of citral. The effect of various operation conditions, in term of feed concentration, catalyst loading, temperature, and reaction time were also studied. The liquid products produced were analyzed by using Gas Chromatography-Mass Spectroscopy (GC-MS). The result of catalytic activity tests showed nickel skeletal catalyst exhibits best catalytic activity in hydrogenation of citral. The optimum of operation condition was achieved in citral concentration 0.1 M with nickel skeletal catalyst loading of 10% (w/w) at 80 °C and 20 bar for 2 hours produced the highest conversion as of 64.20% and the dominant product resulted was citronellal as of 56.48%.

  5. Gasification of Nickel-Preloaded Oil Palm Biomass with Air

    Directory of Open Access Journals (Sweden)

    Syed Shatir A. Syed-Hassan

    2016-10-01

    Full Text Available This study experimentally investigates the gasification of nickel-preloaded oil palm biomass as an alternative catalytic approach to produce clean syngas. To eliminate the use of catalyst support, nickel was added directly to the oil palm mesocarp fiber via ion-exchange using an aqueous solution of nickel nitrate. Nickel species was found to disperse very well on the biomass at a nano-scale dispersion. The presence of the finely dispersed nickels on biomass enhanced syngas production and reduced tar content in the producer gas during the air gasification of biomass. It is believed that nickel particles attached on the biomass and its char promote the catalytic cracking of tar on their surface and supply free radicals to the gas phase to enhance the radical-driven gas-phase reactions for the reforming of high molecular weight hydrocarbons. The unconsumed nickel-containing char shows great potential to be re-utilised as a catalyst to further enhance the destruction of tar components in the secondary tar reduction process. Copyright © 2016 BCREC GROUP. All rights reserved Received: 12nd September 2015; Revised: 10th January 2016; Accepted:16th January 2016 How to Cite: Syed-Hassan, S.S.A., Nor-Azemi, S. (2016. Gasification of Nickel-Preloaded Oil Palm Biomass with Air. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (3: 262-272 (doi:10.9767/bcrec.11.3.566.262-272 Permalink/DOI: http://doi.org/10.9767/bcrec.11.3.566.262-272

  6. Catalyst mixtures

    Science.gov (United States)

    Masel, Richard I.; Rosen, Brian A.

    2017-02-14

    Catalysts that include at least one catalytically active element and one helper catalyst can be used to increase the rate or lower the overpotential of chemical reactions. The helper catalyst can simultaneously act as a director molecule, suppressing undesired reactions and thus increasing selectivity toward the desired reaction. These catalysts can be useful for a variety of chemical reactions including, in particular, the electrochemical conversion of CO.sub.2 or formic acid. The catalysts can also suppress H.sub.2 evolution, permitting electrochemical cell operation at potentials below RHE. Chemical processes and devices using the catalysts are also disclosed, including processes to produce CO, OH.sup.-, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, O.sub.2, H.sub.2, (COOH).sub.2, or (COO.sup.-).sub.2, and a specific device, namely, a CO.sub.2 sensor.

  7. Contaminated nickel scrap processing

    Energy Technology Data Exchange (ETDEWEB)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include {sup 234}Th, {sup 234}Pa, {sup 137}Cs, {sup 239}Pu (trace), {sup 60}Co, U, {sup 99}Tc, and {sup 237}Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs.

  8. Effect of nickel introduced by electroplating on pyrocarbon deposition of carbon-fiber preforms

    Directory of Open Access Journals (Sweden)

    Ren Yancai

    2014-08-01

    Full Text Available In order to improve the deposition rate and microstructure of pyrocarbon, nickel was introduced by electroplating on carbon fibers and used as a catalyst during the deposition of pyrocarbon at 1000 °C using methane as a precursor gas. The distribution of nickel catalyst and the microstructure of pyrocarbon were characterized by scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS, X-ray diffraction (XRD, and Raman micro-spectrometry. Results show that nano-sized nickel particles could be well distributed on carbon fibers and the pyrocarbon deposited catalytically had a smaller d002 value and a higher graphitization degree compared with that without catalyst. In addition, the deposition rate of pyrocarbon in each hour was measured. The deposition rate of pyrocarbon in the first hour was more than 10 times when carbon cloth substrates were doped with nickel catalysts as compared to the pure carbon cloths. The pyrocarbon gained by rapid deposition may include two parts, which are generation directly on the nickel catalyst and formation with the carbon nanofibers as crystal nucleus.

  9. Nickel Curie Point Engine

    Science.gov (United States)

    Chiaverina, Chris; Lisensky, George

    2014-01-01

    Ferromagnetic materials such as nickel, iron, or cobalt lose the electron alignment that makes them attracted to a magnet when sufficient thermal energy is added. The temperature at which this change occurs is called the "Curie temperature," or "Curie point." Nickel has a Curie point of 627 K, so a candle flame is a sufficient…

  10. Production Hydrogen And Nanocarbon Via Methane Decomposition Using Ni-Based Catalysts. Effect Of Acidity And Catalyst Diameter

    Directory of Open Access Journals (Sweden)

    Widodo Purwanto

    2010-10-01

    Full Text Available Objectives of this research are mainly to study impacts of acidity strength (by varying amount of precipitant and loading Al-Si and the effect of nickel particle size (by varying calcinations temperature on decomposition reaction performances. In this research, high-nickel-loaded catalyst is prepared with two methods. Ni-Cu/Al catalysts were prepared with co-precipitation method. While the Ni-Cu/Al-Si catalyst were prepared by combined co-precipitation and sol-gel method. The direct cracking of methane was performed in 8mm quartz fixed bed reactor at atmospheric pressure and 500-700°C. The main  results showed that the Al content of catalyst increases with the increasing amount of precipitant. The activity of catalyst increases with the increasing of catalyst's acidity to the best possible point, and then increasing of acidity will reduce the activity of catalyst. Ni-Cu/4Al and Ni-Cu/11Al deactivated in a  very short time hence produced fewer amount of nanocarbon, while Ni-Cu/15Al was active in a very  long period. The most effective catalyst is Ni-Cu/22Al, which produced the biggest amount of nanocarbon (4.15 g C/g catalyst. Ni catalyst diameter has significant effect on reaction performances mainly  methane conversion and product yield. A small Ni crystal size gave a high methane conversion, a fast deactivation and a low carbon yield. Large Ni particle  diameter yielded a slow decomposition and low methane conversion. The highest methane  conversion was produced by catalyst diameter of 4 nm and maximum yield of carbon of 4.08 g C/ g catalyst was achieved by 15.5 nm diameter of Ni catalyst.

  11. Synthesis, characterization and catalytic application of Ni catalysts ...

    Indian Academy of Sciences (India)

    TEM micrographs of nickel catalysts revealed particles in the size range of 10–30 nm. The Ni/Al 2 O 3 –ZrO 2 catalysts were tested in the steam reforming reaction of ethanol (SRE) at 500 ∘ C, and the obtained results suggest that the differences in catalytic activities depended on the content of ZrO 2 . The selectivity towards ...

  12. Design of a surface alloy catalyst for steam reforming

    DEFF Research Database (Denmark)

    Besenbacher, F.; Chorkendorff, Ib; Clausen, B.S.

    1998-01-01

    Detailed studies of elementary chemical processes on well-characterized single crystal surfaces have contributed substantially to the understanding of heterogeneous catalysis. insight into the structure of surface alloys combined with an understanding of the relation between the surface compositi...... and reactivity is shown to lead directly to new ideas for catalyst design, The feasibility of such an approach is illustrated by the synthesis, characterization, and tests of a high-surface area gold-nickel catalyst for steam reforming....

  13. Highly dispersed metal catalyst

    Science.gov (United States)

    Xiao, Xin; West, William L.; Rhodes, William D.

    2016-11-08

    A supported catalyst having an atomic level single atom structure is provided such that substantially all the catalyst is available for catalytic function. A process of forming a single atom catalyst unto a porous catalyst support is also provided.

  14. Recycling of polymer waste with fluid catalytic cracking catalysts.

    Science.gov (United States)

    Ali, Salmiaton; Garforth, Arthur; Fakhru'l-Razi, A

    2006-01-01

    Feedstock recycling of high-density polyethylene (HDPE) over fluid catalytic cracking (FCC) catalysts (1:6 ratio) was carried out using a laboratory fluidized bed reactor operating at 450 degrees C. Fresh and steam deactivated commercial FCC catalysts with different levels of rare earth oxide (REO) were compared as well as used FCC catalysts (E-Cats) with different levels of metal poisoning. Fresh FCC catalysts gave the highest results of HDPE degradation in terms of yield of volatile hydrocarbon product. Meanwhile, steamed FCC catalysts and used FCC catalysts showed similar but lower yields. Overall, the product yields from HDPE cracking showed that the level of metal contamination (nickel and vanadium) did not affect the product stream generated from polymer cracking. This study gives promising results as an alternative technique for the cracking and recycling of polymer waste.

  15. Bimetal catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K. Y. Simon; Salley, Steve O.; Wang, Huali

    2017-10-03

    A catalyst comprises a carbide or nitride of a metal and a promoter element. The metal is selected from the group consisting of Mo, W, Co, Fe, Rh or Mn, and the promoter element is selected from the group consisting of Ni, Co, Al, Si, S or P, provided that the metal and the promoter element are different. The catalyst also comprises a mesoporous support having a surface area of at least about 170 m.sup.2 g.sup.-1, wherein the carbide or nitride of the metal and the promoter element is supported by the mesoporous support, and is in a non-sulfided form and in an amorphous form.

  16. Catalyst Architecture

    DEFF Research Database (Denmark)

    Kiib, Hans; Marling, Gitte; Hansen, Peter Mandal

    2014-01-01

    How can architecture promote the enriching experiences of the tolerant, the democratic, and the learning city - a city worth living in, worth supporting and worth investing in? Catalyst Architecture comprises architectural projects, which, by virtue of their location, context and their combination...... of programs, have a role in mediating positive social and/or cultural development. In this sense, we talk about architecture as a catalyst for: sustainable adaptation of the city’s infrastructure appropriate renovation of dilapidated urban districts strengthening of social cohesiveness in the city development...

  17. Non-Precious Bimetallic Catalysts for Selective Dehydrogenation of an Organic Chemical Hydride System

    KAUST Repository

    Shaikh Ali, Anaam

    2015-07-06

    Methylcyclohexane (MCH)-Toluene (TOL) chemical hydride cycles as a hydrogen carrier system is successful with the selective dehydrogenation reaction of MCH to TOL, which has been achieved only using precious Pt-based catalysts. Herein, we report improved selectivity using non-precious metal nickel-based bimetallic catalysts, where the second metal occupies the unselective step sites.

  18. Catalysts and conditions for the highly efficient, selective and stable heterogeneous oligomerisation of ethylene

    CSIR Research Space (South Africa)

    Heveling, J

    1998-10-11

    Full Text Available The oligomerisation of ethylene into products in the C-4-C-20 range over heterogeneous nickel catalysts in a fixed-bed reactor at low temperature and high pressure (LT-HP) is reported. The catalysts were obtained by Ni (II) exchange or impregnation...

  19. Ni(0-CMC-Na Nickel Colloids in Sodium Carboxymethyl-Cellulose: Catalytic Evaluation in Hydrogenation Reactions

    Directory of Open Access Journals (Sweden)

    Abdallah Karim

    2011-01-01

    Full Text Available A recyclable catalyst, Ni(0-CMC-Na, composed of nickel colloids dispersed in a water soluble bioorganic polymer, sodium carboxymethylcellulose (CMC-Na, was synthesized by a simple procedure from readily available reagents. The catalyst thus obtained is stable and highly active in alkene hydrogenations.

  20. Hydrogenation of the Exocyclic Olefinic Bond at C-16/C-17 Position of ent-Kaurane Diterpene Glycosides of Stevia rebaudiana Using Various Catalysts

    Science.gov (United States)

    Chaturvedula, Venkata Sai Prakash; Prakash, Indra

    2013-01-01

    Catalytic hydrogenation of the exocyclic double bond present between C16 and C17 carbons of the four ent-kaurane diterpene glycosides namely rebaudioside A, rebaudioside B, rebaudioside C, and rebaudioside D isolated from Stevia rebaudiana has been carried out using Pt/C, Pd(OH)2, Rh/C, Raney Ni, PtO2, and 5% Pd/BaCO3 to their corresponding dihydro derivatives with 17α and 17β methyl group isomers. Reactions were performed using the above-mentioned catalysts with the solvents methanol, water, and ethanol/water (8:2) under various conditions. Synthesis of reduced steviol glycosides was performed using straightforward chemistry and their structures were characterized on the basis of 1D and 2D NMR spectral data, including a comparison with reported spectral data. PMID:23896597

  1. Hydrogenation of the Exocyclic Olefinic Bond at C-16/C-17 Position of ent-Kaurane Diterpene Glycosides of Stevia rebaudiana Using Various Catalysts

    Directory of Open Access Journals (Sweden)

    Indra Prakash

    2013-07-01

    Full Text Available Catalytic hydrogenation of the exocyclic double bond present between C16 and C17 carbons of the four ent-kaurane diterpene glycosides namely rebaudioside A, rebaudioside B, rebaudioside C, and rebaudioside D isolated from Stevia rebaudiana has been carried out using Pt/C, Pd(OH2, Rh/C, Raney Ni, PtO2, and 5% Pd/BaCO3 to their corresponding dihydro derivatives with 17α and 17β methyl group isomers. Reactions were performed using the above-mentioned catalysts with the solvents methanol, water, and ethanol/water (8:2 under various conditions. Synthesis of reduced steviol glycosides was performed using straightforward chemistry and their structures were characterized on the basis of 1D and 2D NMR spectral data, including a comparison with reported spectral data.

  2. Oligomerization of ethylene catalysed by nickel complexes associated with nitrogen ligands in ionic liquids; Oligomerisation de l'ethylene catalysee par des complexes du nickel associes a des ligands azotes dans les liquides ioniques

    Energy Technology Data Exchange (ETDEWEB)

    Lecocq, V.

    2003-09-01

    We report here the use of a new class of catalytic systems based on a nickel active center associated with nitrogen ligands, such as di-imines, or imino-pyridines, for the oligomerization of ethylene in a biphasic medium using ionic liquids as the catalyst solvent. The nickel catalyst is immobilized in the ionic liquid phase in which the olefinic reaction products are poorly miscible. This biphasic system makes possible an easy separation and recycle of the catalyst. Numerous di-imine and imino-pyridine ligands with different steric and electronic properties have been synthesized and their corresponding nickel complexes isolated and characterized. Different ionic liquids, based on chloro-aluminates or non-chloro-aluminates anions, have also been prepared and characterized. The effect of the nature of the ligand, the ionic liquid, the nickel precursor and its mode of activation have been studied and correlated with the selectivity and activity of the transformation of ethylene. (author)

  3. Coal catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kroenig, W.

    1944-02-11

    Some considerations in the selection of a catalyst for the liquid phase of coal hydrogenation are discussed. Some of the previous history of such selections is mentioned. At one stage of the development, the principal catalyst had been iron sulfate (FeSO/sub 4/.7H/sub 2/O). Later, for reasons of cost and availability of large supplies, selections had turned to mixtures of iron sulfate and one or another of some iron oxide- and aluminum oxide-containing byproducts of aluminum manufacture, namely Bayermasse, Luxamsse, or Lautamasse. Much of the discussion centered on optimal proportions for such mixtures, particularly as related to pH values of resulting coal pastes. Upper Silesian coal was more alkaline than Ruhr coal, and Bayermasse, etc., were quite alkaline. Thus, since the iron sulfate served as a partial neutralizer for the coal as well as a catalyst, it seemed necessary to increase the proportions of iron sulfate in the catalyst mixture when processing coal of greater alkalinity. A further reason for a greater proportion of iron sulfate seemed to be that most of the catalytic activity of the iron came from the ferrous iron of iron sulfate rather than from the ferric iron of the other materials. Ferrous-ferric ratios also seemed to indicate that Luxmasse or Lautamasse might be better catalyst components than Bayermasse but their water content sometimes caused handling problems, so Bayermasse had been more widely used. Formation of deposits in the preheater was more likely due to the Bayermasse than to the iron sulfate; sodium sulfide could help to prevent them.

  4. Nickel and Epigenetic Gene Silencing

    OpenAIRE

    Hong Sun; Magdy Shamy; Max Costa

    2013-01-01

    Insoluble nickel compounds are well-established human carcinogens. Occupational exposure to these compounds leads to increased incidence of lung and nasal cancer in nickel refinery workers. Apart from its weak mutagenic activity and hypoxia mimicking effect there is mounting experimental evidence indicating that epigenetic alteration plays an important role in nickel-induced carcinogenesis. Multiple epigenetic mechanisms have been identified to mediate nickel-induced gene silencing. Nickel io...

  5. NICKEL – ENVIRONMENTAL ALLERGEN

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-06-01

    Full Text Available Nickel (Ni is ubiquitus in our biosphere because of its emission from natural and anthropogenic sources. Its toxic and carcinogenic properties are well recognised only in workers exposed to high Ni concentrations. Nickel allergy is the most common form of cutaneus hypersensitivity in general population and also in occupationally exposed groups. As sensitizing agent Ni has a high prevalence of allergic contact dermatitis. The most important known risk factor associated with nickel allergy is ear piercing and use of other jewelry in females. In general population 17 % adults and 8 % children have Ni allergy symptoms. Permanently growing Ni allergy is regarded as serious risk for public health.

  6. Identification of non-precious metal alloy catalysts for selective hydrogenation of acetylene

    DEFF Research Database (Denmark)

    Studt, Felix; Abild-Pedersen, Frank; Bligaard, Thomas

    2008-01-01

    The removal of trace acetylene from ethylene is performed industrially by palladium hydrogenation catalysts ( often modified with silver) that avoid the hydrogenation of ethylene to ethane. In an effort to identify catalysts based on less expensive and more available metals, density functional...... calculations were performed that identified relations in heats of adsorption of hydrocarbon molecules and fragments on metal surfaces. This analysis not only verified the facility of known catalysts but identified nickel- zinc alloys as alternatives. Experimental studies demonstrated that these alloys...

  7. Electroplated tin-nickel coatings as a replacement for nickel to eliminate nickel dermatitis

    DEFF Research Database (Denmark)

    Møller, Per; Boyce, Jan M.; Nielsen, Lars Pleth

    2013-01-01

    Nickel dermatitis (skin allergy) is a growing problem in numerous countries. The alarming frequency of sensitization to nickel especially in the US caused nickel to be selected as the "Allergen of the Year" in 2008 by the American Contact Dermatitis Society. Nickel as coating in contact with skin...... and immersion test of tin/nickel coatings in artificial sweat. Copyright © (2013) by the National Association for Surface Finishing....

  8. Reduction of a Ni/Spinel Catalyst for Methane Reforming

    DEFF Research Database (Denmark)

    Kehres, Jan; Andreasen, Jens Wenzel; Fløystad, Jostein Bø

    2015-01-01

    A nickel/spinel (Ni/MgAl2O4) catalyst, w(Ni) = 22 wt%, was investigated in situ during reduction with wide angle X-ray scattering (WAXS) in a laboratory setup and with anomalous small angle X-ray scattering (ASAXS) at a synchrotron source. Complementary high resolution transmission electron...... microscopy (HRTEM) was performed on the fresh catalyst sample. The Ni particles in the fresh catalyst sample were observed to exhibit a Ni/NiO core/shell structure. A decrease of the Ni lattice parameter is observed during the reduction in a temperature interval from 413 – 453 K, which can be related...

  9. Properties of the FCC Catalyst Additive Prepared from Guizhou Kaoline

    Directory of Open Access Journals (Sweden)

    Xianlun Xu

    2006-09-01

    Full Text Available The properties of a FCC catalyst additive prepared from Guizhou kaoline were extensively investigated. The samples were characterized by N2 adsorption, X-ray diffraction, IR spectrometry, and scanning electron microscope (SEM. The results showed that the crystallinity of NaY zeolite synthesized from this kaoline was 25% and the silica alumina ratio was rk/s ˇ m = 5.05. The catalyst additive prepared from above crystallization product exhibited excellent performance of nickel and vanadium passivation, offered 21% lower coke versus base catalyst, while maintaining high bottoms upgrading selectivity.

  10. Homogeneous catalyst formulations for methanol production

    Science.gov (United States)

    Mahajan, Devinder; Sapienza, Richard S.; Slegeir, William A.; O'Hare, Thomas E.

    1990-01-01

    There is disclosed synthesis of CH.sub.3 OH from carbon monoxide and hydrogen using an extremely active homogeneous catalyst for methanol synthesis directly from synthesis gas. The catalyst operates preferably between 100.degree.-150.degree. C. and preferably at 100-150 psia synthesis gas to produce methanol. Use can be made of syngas mixtures which contain considerable quantities of other gases, such as nitrogen, methane or excess hydrogen. The catalyst is composed of two components: (a) a transition metal carbonyl complex and (b) an alkoxide component. In the simplest formulation, component (a) is a complex of nickel tetracarbonyl and component (b) is methoxide (CH.sub.3 O.sup.13 ), both being dissolved in a methanol solvent system. The presence of a co-solvent such as p-dioxane, THF, polyalcohols, ethers, hydrocarbons, and crown ethers accelerates the methanol synthesis reaction.

  11. Protein Scaffolding for Small Molecule Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Baker, David [Univ. of Washington, Seattle, WA (United States)

    2014-09-14

    We aim to design hybrid catalysts for energy production and storage that combine the high specificity, affinity, and tunability of proteins with the potent chemical reactivities of small organometallic molecules. The widely used Rosetta and RosettaDesign methodologies will be extended to model novel protein / small molecule catalysts in which one or many small molecule active centers are supported and coordinated by protein scaffolding. The promise of such hybrid molecular systems will be demonstrated with the nickel-phosphine hydrogenase of DuBois et. al.We will enhance the hydrogenase activity of the catalyst by designing protein scaffolds that incorporate proton relays and systematically modulate the local environment of the catalyticcenter. In collaboration with DuBois and Shaw, the designs will be experimentally synthesized and characterized.

  12. Dry Reforming of Methane Using a Nickel Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Jonas M. Leimert

    2017-12-01

    Full Text Available Dry reforming is a very interesting process for synthesis gas generation from CH 4 and CO 2 but suffers from low hydrogen yields due to the reverse water–gas shift reaction (WGS. For this reason, membranes are often used for hydrogen separation, which in turn leads to coke formation at the process temperatures suitable for the membranes. To avoid these problems, this work shows the possibility of using nickel self-supported membranes for hydrogen separation at a temperature of 800 ∘ C. The higher temperature effectively suppresses coke formation. The paper features the analysis of the dry reforming reaction in a nickel membrane reactor without additional catalyst. The measurement campaign targeted coke formation and conversion of the methane feedstock. The nickel approximately 50% without hydrogen separation. The hydrogen removal led to an increase in methane conversion to 60–90%.

  13. Activation and regeneration of a NiMo/Al[sub 2]O[sub 3] hydrotreatment catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira da Silva, V.L.S.; Schmal, M. (Univ. Federal, Rio de Janeiro (Brazil)); Frety, R. (CNRS, Villeurbanne (France). Inst. de Reserches sur la Catalyse)

    1994-07-01

    Activation and regeneration procedures applied to a nickel-molybdenum on alumina catalyst, both fresh and spent, were tested by the hydrodesulfurization of thiophene. Characterization techniques used included temperature programmed reduction and oxidation (TPR,TPO), diffuse reflectance spectroscopy (DRS), and X-ray diffraction (XRD). The fresh catalyst was treated by sulfiding, reoxidation, and resulfiding. This sequence was found to be more effective than one sulfiding step, possibly because of the formation of a nickel molybdate phase during reoxidation. The spent catalyst could not be regenerated completely although its original surface properties were attained. The loss of activity of the spent catalysts was alluded by TPO to result from nickel-molybdenum segregation which probably happened because of the excessive heat from burning the coke present on the catalyst.

  14. Novel anode catalyst for direct methanol fuel cells.

    Science.gov (United States)

    Basri, S; Kamarudin, S K; Daud, W R W; Yaakob, Z; Kadhum, A A H

    2014-01-01

    PtRu catalyst is a promising anodic catalyst for direct methanol fuel cells (DMFCs) but the slow reaction kinetics reduce the performance of DMFCs. Therefore, this study attempts to improve the performance of PtRu catalysts by adding nickel (Ni) and iron (Fe). Multiwalled carbon nanotubes (MWCNTs) are used to increase the active area of the catalyst and to improve the catalyst performance. Electrochemical analysis techniques, such as energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS), are used to characterize the kinetic parameters of the hybrid catalyst. Cyclic voltammetry (CV) is used to investigate the effects of adding Fe and Ni to the catalyst on the reaction kinetics. Additionally, chronoamperometry (CA) tests were conducted to study the long-term performance of the catalyst for catalyzing the methanol oxidation reaction (MOR). The binding energies of the reactants and products are compared to determine the kinetics and potential surface energy for methanol oxidation. The FESEM analysis results indicate that well-dispersed nanoscale (2-5 nm) PtRu particles are formed on the MWCNTs. Finally, PtRuFeNi/MWCNT improves the reaction kinetics of anode catalysts for DMFCs and obtains a mass current of 31 A g(-1) catalyst.

  15. Novel Anode Catalyst for Direct Methanol Fuel Cells

    Directory of Open Access Journals (Sweden)

    S. Basri

    2014-01-01

    Full Text Available PtRu catalyst is a promising anodic catalyst for direct methanol fuel cells (DMFCs but the slow reaction kinetics reduce the performance of DMFCs. Therefore, this study attempts to improve the performance of PtRu catalysts by adding nickel (Ni and iron (Fe. Multiwalled carbon nanotubes (MWCNTs are used to increase the active area of the catalyst and to improve the catalyst performance. Electrochemical analysis techniques, such as energy dispersive X-ray spectrometry (EDX, X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, and X-ray photoelectron spectroscopy (XPS, are used to characterize the kinetic parameters of the hybrid catalyst. Cyclic voltammetry (CV is used to investigate the effects of adding Fe and Ni to the catalyst on the reaction kinetics. Additionally, chronoamperometry (CA tests were conducted to study the long-term performance of the catalyst for catalyzing the methanol oxidation reaction (MOR. The binding energies of the reactants and products are compared to determine the kinetics and potential surface energy for methanol oxidation. The FESEM analysis results indicate that well-dispersed nanoscale (2–5 nm PtRu particles are formed on the MWCNTs. Finally, PtRuFeNi/MWCNT improves the reaction kinetics of anode catalysts for DMFCs and obtains a mass current of 31 A g−1 catalyst.

  16. Germanium nanowires grown using different catalyst metals

    Energy Technology Data Exchange (ETDEWEB)

    Gouveia, R.C., E-mail: riama@ifsp.edu.br [Departamento de Física – NanO Lab, Universidade Federal de São Carlos, Rod. Washington Luís, Km 235 – SP 310, São Carlos, CEP 13565-905 (Brazil); Área de Ciências, Instituto Federal de Educação Ciência e Tecnologia de São Paulo, Rua Américo Ambrósio, 269, Jd. Canaã, Sertãozinho, CEP 14169-263 (Brazil); Kamimura, H.; Munhoz, R.; Rodrigues, A.D. [Departamento de Física – NanO Lab, Universidade Federal de São Carlos, Rod. Washington Luís, Km 235 – SP 310, São Carlos, CEP 13565-905 (Brazil); Leite, E.R. [Departamento de Química – LIEC, Universidade Federal de São Carlos, São Carlos, CEP 13565-905 (Brazil); Chiquito, A.J. [Departamento de Física – NanO Lab, Universidade Federal de São Carlos, Rod. Washington Luís, Km 235 – SP 310, São Carlos, CEP 13565-905 (Brazil)

    2016-11-01

    Germanium nanowires have been synthesized by the well known vapor-liquid-solid growth mechanism using gold, silver, cooper, indium and nickel as catalyst metals. The influence of metal seeds on nanowires structural and electronic transport properties was also investigated. Electron microscopy images demonstrated that, despite differences in diameters, all nanowires obtained presented single crystalline structures. X-ray patterns showed that all nanowires were composed by germanium with a small amount of germanium oxide, and the catalyst metal was restricted at the nanowires' tips. Raman spectroscopy evidenced the long range order in the crystalline structure of each sample. Electrical measurements indicated that variable range hopping was the dominant mechanism in carrier transport for all devices, with similar hopping distance, regardless the material used as catalyst. Then, in spite of the differences in synthesis temperatures and nanowires diameters, the catalyst metals have not affected the composition and crystalline quality of the germanium nanowires nor the carrier transport in the germanium nanowire network devices. - Highlights: • Ge nanowires were grown by VLS method using Au, Ag, Cu, In and Ni as catalysts. • All nanowires presented high single crystalline quality and long range order. • Devices showed semiconducting behavior having VRH as dominant transport mechanism. • The metal catalyst did not influence structural properties or the transport mechanism.

  17. Influence of temperature on the results of prehydrogenation (saturation) with concentrated and diluted catalysts. The preparation of such catalysts

    Energy Technology Data Exchange (ETDEWEB)

    1943-05-24

    In July 1941 systematic tests had been made with the alumina--molybdenum--nickel catalyst 7846. The results of those tests were summarized in this report. A test with catalyst 5058 was underway at this time and a test with alumina--tungsten--nickel catalyst 7846 W250-8376 was planned. In prehydrogenation of bituminous coal middle oils with catalyst 7846, usually done at 434/sup 0/C, the temperature was varied and it was observed that: at 300/sup 0/C, the catalyst began to show hydrogenation effects and to reduce phenols and nitrogen compounds; at 442/sup 0/C maximum hydrogenation effect was obtained; practically no splitting of C-C bonds took place below 434/sup 0/C; and below 434/sup 0/C the catalyst worked fully reversibly with respect to temperature change. The preparation of catalyst 6434 was discussed. Adsorption of hydrogen by tungsten sulfide was also a topic of this report, and it included the preparation of WS/sub 2/. Studies of the adsorption at about 25/sup 0/C showed adsorption increased appreciably up to 48 hours. The final value was fairly constant down to pressures under 100 mm and equaled about 1 ccH/sub 2//gWS/sub 2/. At pressures below 100 mm the quantity adsorbed dropped rapidly and equalled only .45 ccH/sub 2//gWS/sub 2/ at 13 mm Hg.

  18. Hydrogenation of Tetralin over Supported Ni and Ir Catalysts

    Directory of Open Access Journals (Sweden)

    Dipali P. Upare

    2013-01-01

    Full Text Available Selective hydrogenation and ring opening (SRO of tetrahydronaphthalene (tetralin was studied over nickel and iridium supported catalysts in the context of the removal of polynuclear aromatics from diesel fuel. The tetralin hydrogenation was carried out in a fixed-bed reactor at 270°C, using H2 pressure of 30 bars, WHSV of 2.3 h−1, and H2/feed molar ratio of 40; the resultant products were analyzed by GC and GC-MS. The Ir/SiO2 catalyst gave 85% of tetralin conversion and 75.1% of decalin products selectivity whereas Ni/SiO2 catalyst showed an unprecedented high catalytic performance with 88.3% of tetralin conversion and 93% of decalin products selectivity. The catalysts were characterized by using different characterization techniques such as XRD, TPR, and HR-TEM to know the physicochemical properties as well as active sites in the catalysts.

  19. Highly Dispersed Nickel-Containing Mesoporous Silica with Superior Stability in Carbon Dioxide Reforming of Methane: The Effect of Anchoring.

    Science.gov (United States)

    Cai, Wenjia; Ye, Lin; Zhang, Li; Ren, Yuanhang; Yue, Bin; Chen, Xueying; He, Heyong

    2014-03-19

    A series of nickel-containing mesoporous silica samples (Ni-SiO₂) with different nickel content (3.1%-13.2%) were synthesized by the evaporation-induced self-assembly method. Their catalytic activity was tested in carbon dioxide reforming of methane. The characterization results revealed that the catalysts, e.g., 6.7%Ni-SiO₂, with highly dispersed small nickel particles, exhibited excellent catalytic activity and long-term stability. The metallic nickel particle size was significantly affected by the metal anchoring effect between metallic nickel particles and unreduced nickel ions in the silica matrix. A strong anchoring effect was suggested to account for the remaining of small Ni particle size and the improved catalytic performance.

  20. Highly Dispersed Nickel-Containing Mesoporous Silica with Superior Stability in Carbon Dioxide Reforming of Methane: The Effect of Anchoring

    Directory of Open Access Journals (Sweden)

    Wenjia Cai

    2014-03-01

    Full Text Available A series of nickel-containing mesoporous silica samples (Ni-SiO2 with different nickel content (3.1%–13.2% were synthesized by the evaporation-induced self-assembly method. Their catalytic activity was tested in carbon dioxide reforming of methane. The characterization results revealed that the catalysts, e.g., 6.7%Ni-SiO2, with highly dispersed small nickel particles, exhibited excellent catalytic activity and long-term stability. The metallic nickel particle size was significantly affected by the metal anchoring effect between metallic nickel particles and unreduced nickel ions in the silica matrix. A strong anchoring effect was suggested to account for the remaining of small Ni particle size and the improved catalytic performance.

  1. The cost of nickel allergy

    DEFF Research Database (Denmark)

    Hamann, Carsten R; Hamann, Dathan; Hamann, Curtis

    2013-01-01

    Background. Nickel is widely used in coins; nickel may cause contact allergy and allergic contact dermatitis in those who handle them. Objectives. To investigate alloy use, coin composition and nickel and cobalt release for a worldwide selection of currently circulating coins. Materials and methods...

  2. Pulse Reversal Plating of Nickel and Nickel Alloys for MEMS

    DEFF Research Database (Denmark)

    Tang, Peter Torben

    2001-01-01

    Pulse plating has previously been reported to improve the properties of nickel and nickel alloy deposits. Typically, focus has been on properties such as grain size, hardness and smoothness. When pulse plating is to be utilized for micro electromechanical systems (MEMS), internal stress...... and material distribution is even more important. Using a bath consisting mostly of nickel chloride, pulse reversal plating of both pure nickel and nickel-cobalt alloys has been used to fabricate tools for micro-injection molding. Pulse reversal plating of ternary soft-magnetic alloys, comprising 45-65 percent...

  3. Development of methane reformer from calcium aluminosilicate coated with nickel

    Energy Technology Data Exchange (ETDEWEB)

    Silvano, W.F.; Silva, L. da; Bernardin, A.M. [Universidade Estadual de Santa Catarina (UNESC), Criciuma, SC (Brazil); Huertas, C.S. [Instituto de Infectologia Emilio Ribas (IIER), Sao Paulo, SP (Brazil)

    2009-07-01

    Full text: This work deals with the development of a reformer from alkali metal aluminosilicate coated with nickel for the generation of hydrogen from biogas (methane). The catalysts were prepared by sintering the aluminosilicate (Al2O3.SiO2) with CaO (5%, 10% and 20%wt) and subsequent coating them with Ni (nitrate). The CaO was incorporated as carbonate, with PSD control. The reformers were characterized (XRF, XRD, PSD, DTA, SEM and diametral compression resistance). The reformer impregnation with the metal catalyst (Ni) occurred by immersing the ceramics into nitrate, with subsequent drying and analysis of catalytic activity at atmospheric pressure using methane gas as reagent (chromatography). The preliminary results show that the catalysts have good catalytic activity, and the route used has shown to be economically and technically feasible. (author)

  4. Full Scale Alternative Catalyst Testing for Bosch Reactor Optimization

    Science.gov (United States)

    Barton, Katherine; Abney, Morgan B.

    2011-01-01

    Current air revitalization technology onboard the International Space Station (ISS) cannot provide complete closure of the oxygen and hydrogen loops. This makes re-supply necessary, which is possible for missions in low Earth orbit (LEO) like the ISS, but unviable for long term space missions outside LEO. In comparison, Bosch technology reduces carbon dioxide with hydrogen, traditionally over a steel wool catalyst, to create water and solid carbon. The Bosch product water can then be fed to the oxygen generation assembly to produce oxygen for crew members and hydrogen necessary to reduce more carbon dioxide. Bosch technology can achieve complete oxygen loop closure, but has many undesirable factors that result in a high energy, mass, and volume system. Finding a different catalyst with an equal reaction rate at lower temperatures with less catalyst mass and longer lifespan would make a Bosch flight system more feasible. Developmental testing of alternative catalysts for the Bosch has been performed using the Horizontal Bosch Test Stand. Nickel foam, nickel shavings, and cobalt shavings were tested at 500 C and compared to the original catalyst, steel wool. This paper presents data and analysis on the performance of each catalyst tested at comparable temperatures and recycle flow rates.

  5. Low-Temperature Synthesis of Hierarchical Amorphous Basic Nickel Carbonate Particles for Water Oxidation Catalysis.

    Science.gov (United States)

    Yang, Yisu; Liang, Fengli; Li, Mengran; Rufford, Thomas E; Zhou, Wei; Zhu, Zhonghua

    2015-07-08

    Amorphous nickel carbonate particles are catalysts for the oxygen evolution reaction (OER), which plays a critical role in the electrochemical splitting of water. The amorphous nickel carbonate particles can be prepared at a temperature as low as 60 °C by an evaporation-induced precipitation (EIP) method. The products feature hierarchical pore structures. The mass-normalized activity of the catalysts, measured at an overpotential of 0.35 V, was 55.1 A g(-1) , with a Tafel slope of only 60 mV dec(-1) . This catalytic activity is superior to the performance of crystalline NiOx particles and β-Ni(OH)2 particles, and compares favorably to state-of-the-art RuO2 catalysts. The activity of the amorphous nickel carbonate is remarkably stable during a 10 000 s chronoamperometry test. Further optimization of synthesis parameters reveals that the amorphous structure can be tuned by adjusting the H2 O/Ni ratio in the precursor mixture. These results suggest the potential application of easily prepared hierarchical basic nickel carbonate particles as cheap and robust OER catalysts with high activity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Cobalt and Nickel Complexes Bearing 2-(2-pyridyl-Benzimidazole: Synthesis and Ethylene Oligomerization

    Directory of Open Access Journals (Sweden)

    Jian-Long Du

    2005-01-01

    Full Text Available A series of cobalt and nickel complexes MLX2 (M=Co or Ni, X=Cl bearing 2-(2-pyridylbenzimidazole ligands were synthesized. Treatment of the complexes with methylaluminoxane (MAO leads to active catalysts for ethylene oligomerization. The oligomers were olefins from C2 to C6.

  7. Epigenetic mechanisms of nickel carcinogenesis.

    Science.gov (United States)

    Salnikow, K; Costa, M

    2000-01-01

    This article considers the mechanism of nickel carcinogenesis, focusing primarily on the epigenetic changes associated with exposure of cells to carcinogenic nickel compounds. We discuss the delivery of nickel in the cell and contrast the genetic and epigenetic changes that have occurred. Within the epigenetic effects, alteration in the levels of transcription factors, such as ATF-1, p53, HIF-1, HIF-1alpha, and NFkappaB, are considered. The relationship between nickel and calcium metabolism and the role it plays in nickel carcinogenesis is also considered, as are reactive oxygen species and the interactions of nickel with proteins. We discuss these epigenetic discussions in light of the effects that nickel has on inducing DNA methylation in cells. It is of interest that nickel induces both a variety of signaling pathways as well as genes that seem to be important for the survival of cancer cells. It is also interesting that the same genes induced or repressed by nickel are similarly overexpressed or not expressed in nickel-transformed cells. It is suggested that this may represent a selection process crucial to the nickel carcinogenesis process.

  8. Nickel in tap water

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Nielsen, G D; Flyvholm, Morten

    1983-01-01

    Nickel analyses of tap water from several sources in Copenhagen gave up to 490 X 10(-6) g X 1(-1) in the first 250 ml portions. Hot water gave higher values than cold water. After flushing for 5 min, low values were found. Considerable variation from time to time and from tap to tap was found...

  9. Nickel and Epigenetic Gene Silencing

    Directory of Open Access Journals (Sweden)

    Hong Sun

    2013-10-01

    Full Text Available Insoluble nickel compounds are well-established human carcinogens. Occupational exposure to these compounds leads to increased incidence of lung and nasal cancer in nickel refinery workers. Apart from its weak mutagenic activity and hypoxia mimicking effect there is mounting experimental evidence indicating that epigenetic alteration plays an important role in nickel-induced carcinogenesis. Multiple epigenetic mechanisms have been identified to mediate nickel-induced gene silencing. Nickel ion is able to induce heterochromatinization by binding to DNA-histone complexes and initiating chromatin condensation. The enzymes required for establishing or removing epigenetic marks can be targeted by nickel, leading to altered DNA methylation and histone modification landscapes. The current review will focus on the epigenetic changes that contribute to nickel-induced gene silencing.

  10. Nickel and epigenetic gene silencing.

    Science.gov (United States)

    Sun, Hong; Shamy, Magdy; Costa, Max

    2013-10-25

    Insoluble nickel compounds are well-established human carcinogens. Occupational exposure to these compounds leads to increased incidence of lung and nasal cancer in nickel refinery workers. Apart from its weak mutagenic activity and hypoxia mimicking effect there is mounting experimental evidence indicating that epigenetic alteration plays an important role in nickel-induced carcinogenesis. Multiple epigenetic mechanisms have been identified to mediate nickel-induced gene silencing. Nickel ion is able to induce heterochromatinization by binding to DNA-histone complexes and initiating chromatin condensation. The enzymes required for establishing or removing epigenetic marks can be targeted by nickel, leading to altered DNA methylation and histone modification landscapes. The current review will focus on the epigenetic changes that contribute to nickel-induced gene silencing.

  11. Molecular biology of nickel carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Costa, M. [Nelson Institute of Environmental Medicine and the Kaplan Comprehensive Cancer Center, New York University Medical Center, NY (United States)

    1998-06-01

    The molecular mechanisms of nickel carcinogenesis are discussed and reviewed with emphasis on work done in my laboratory. The most important determinant of nickel carcinogenesis is the ability of the nickel ion to reach relevant targets for carcinogenesis, which involves chromatin and depends on the ability of the nickel compound to enter cells. The mechanisms that regulate the phagocytosis and intracellular dissolution of the highly carcinogenic particulate nickel compounds are discussed, as is the ability of these nickel compounds to enhance the DNA methylation pattern and turn off the expression of critical tumor suppressor genes. These findings show these nickel compounds to be a somewhat unique class of carcinogens. (orig.) (orig.) With 3 figs., 4 tabs., 31 refs.

  12. Nickel-silver alloy electrocatalysts for hydrogen evolution and oxidation in an alkaline electrolyte.

    Science.gov (United States)

    Tang, Maureen H; Hahn, Christopher; Klobuchar, Aidan J; Ng, Jia Wei Desmond; Wellendorff, Jess; Bligaard, Thomas; Jaramillo, Thomas F

    2014-09-28

    The development of improved catalysts for the hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) in basic electrolytes remains a major technical obstacle to improved fuel cells, water electrolyzers, and other devices for electrochemical energy storage and conversion. Based on the free energy of adsorbed hydrogen intermediates, theory predicts that alloys of nickel and silver are active for these reactions. In this work, we synthesize binary nickel-silver bulk alloys across a range of compositions and show that nickel-silver alloys are indeed more active than pure nickel for hydrogen evolution and, possibly, hydrogen oxidation. To overcome the mutual insolubility of silver and nickel, we employ electron-beam physical vapor codeposition, a low-temperature synthetic route to metastable alloys. This method also produces flat and uniform films that facilitate the measurement of intrinsic catalytic activity with minimal variations in the surface area, ohmic contact, and pore transport. Rotating-disk-electrode measurements demonstrate that the hydrogen evolution activity per geometric area of the most active catalyst in this study, Ni0.75Ag0.25, is approximately twice that of pure nickel and has comparable stability and hydrogen oxidation activity. Our experimental results are supported by density functional theory calculations, which show that bulk alloying of Ni and Ag creates a variety of adsorption sites, some of which have near-optimal hydrogen binding energy.

  13. Regenerability of hydrotalcite-derived nickel-iron alloy nanoparticles for syngas production from biomass tar.

    Science.gov (United States)

    Li, Dalin; Koike, Mitsuru; Wang, Lei; Nakagawa, Yoshinao; Xu, Ya; Tomishige, Keiichi

    2014-02-01

    Nickel-iron/magnesium/aluminum bimetallic catalysts were prepared by the calcination and reduction of nickel-magnesium-iron-aluminum hydrotalcite-like compounds. Characterization suggests that, at iron/nickel≤0.5, both nickel and iron species are homogeneously distributed in the hydrotalcite precursor and incorporated into the Mg(Ni, Fe, Al)O periclase after calcination, giving rise to uniform nickel-iron alloy nanoparticles after reduction. Ni-Fe/Mg/Al (Fe/Ni=0.25) exhibits the best catalytic performance for the steam reforming of tar derived from the pyrolysis of biomass. It is suggested that the uniform nickel-iron alloy nanoparticles and the synergy between nickel and iron are responsible for the high catalytic performance. Moreover, the Ni-Fe/Mg/Al catalyst exhibits much better regenerability toward oxidation-reduction treatment for the removal of deposited coke than that of conventional Ni-Fe/α-Al2 O3 . This property can be attributed to the better regeneration of Ni-Fe alloy nanoparticles through the formation and reduction of Mg(Ni, Fe, Al)O. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Distribution of nickel between copper-nickel and alumina saturated iron silicate slags

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, R.G.; Acholonu, C.C.

    1984-03-01

    The solubility of nickel in slag is determined in this article by equilibrating copper-nickel alloys with alumina-saturated iron silicate slags in an alumina crucible at 1573 K. The results showed that nickel dissolves in slag both as nickel oxide and as nickel metal. The presence of alumina is shown to increase the solubility of nickel in slags.

  15. Ammonia Generation via a Graphene-Coated Nickel Catalyst

    Directory of Open Access Journals (Sweden)

    Fei Lu

    2017-05-01

    Full Text Available A novel graphene-coated Ni electrode was developed in this investigation to improve corrosion resistance while unexpectedly enhancing the ammonia generation rate in the electrochemically induced urea to ammonia (eU2A process, which is an electrochemical onsite ammonia generation method. The development of the electrode is crucial for the eU2A reactions since in the ammonia generation process, the concentration of ammonia is inevitably high on the surface of the electrode, leading to severe corrosion of the electrode and the loss of generated ammonia as well. In this paper, the graphene was derived from raw coal by using the chemical vapor deposition method and self-lifted onto a Ni electrode to form a protective layer for corrosion prevention. Transmission electron microscopy showed the synthesized graphene had few-layers and Raman spectroscopy indicated that the coating of graphene was stable during the eU2A reaction. As a result, the ammonia corrosion of the Ni electrode was dramatically reduced by ~20 times with the graphene coating method. More importantly, a higher ammonia generation rate (~2 times was achieved using the graphene-coated Ni working electrode compared to a bare Ni electrode in the eU2A process.

  16. Half-sandwich nickel(II complexes bearing 1,3-di(cycloalkylimidazol-2-ylidene ligands

    Directory of Open Access Journals (Sweden)

    Johnathon Yau

    2015-11-01

    Full Text Available Two new nickel catalysts have been prepared using a convenient procedure where nickelocene, the NHC·HBF4 salts, and [Et4N]Cl were heated in THF using microwave irradiation. The resulting [NiCl(Cp(NHC] complexes are air- and moisture stable in the solid state, and represent two new members of this valuable and practical class of nickel catalysts. The new species were fully characterised using methods including NMR spectroscopy and X-ray crystallography. When tested in model Suzuki–Miyaura cross-coupling reactions, these complexes were found to be active for the cross-coupling of aryl bromides and aryl chlorides.

  17. PREPARATION AND CHARACTERIZATION THE NON-SULFIDED METAL CATALYST: Ni/USY and NiMo/USY

    Directory of Open Access Journals (Sweden)

    Khoirina Dwi Nugrahaningtyas

    2010-06-01

    Full Text Available The two-new catalysts had been prepared by using the impregnation method according to Nugrahaningtyas [6] and Li [4]. One catalyst is of Nickel (Ni, supported on Ultra Stable Zeolite Y (USY, whereas the other one is NiMo supported on same supporting agent. These new catalysts are expected to be more effective when applied on the hydrotreatment reaction in standpoint of its capabilities on removing the unwanted-heteroatom. Characterization those two types of catalysts then carried out by using the criteria of acidity, porosity and, metal content. The result shows that these non-sulfide catalysts have several good characters that supporting their usefulness in hydrotreatment-catalytic reaction. In addition, catalyst NiMo/USY - 1 performs many ideal criteria as the best functional catalyst.   Keywords: Non-sulfided Catalyst, hydro-treating, preparation, characterization

  18. Nickel(II) Complexes Bearing 4-Arylimino-1,2,3-trihydroacridines: Synthesis, Characterization, and Ethylene Oligomerization

    OpenAIRE

    Wang, Shengdong; Du, Shizhen; Zhang, Wenjuan; Asuha, Sin; Sun, Wen-Hua

    2015-01-01

    Nickel(II) complexes have attracted much attention as a new generation of olefin catalysts since the ?-diiminonickel complex was discovered as a highly efficient procatalyst for ethylene polymerization. A series of novel 4-arylimino-1,2,3-trihydroacridylnickel(II) dihalide complexes was synthesized in a one-pot reaction of 2,3-dihydroacridine-4-one and different anilines with nickel(II) chloride or nickel(II) bromide 1,2-dimethoxyethane complex. The complexes were characterized by infrared sp...

  19. Foundation Flash Catalyst

    CERN Document Server

    Goralski, Greg

    2010-01-01

    This book offers an introduction to Flash Catalyst for designers with intermediate to advanced skills. It discusses where Catalyst sits within the production process and how it communicates with other programs. It covers all of the features of the Flash Catalyst workspace, teaching you how to create designs from scratch, how to build application designs and add functionality, and how to master the Catalyst/Flex workflow. * Introduces Flash Catalyst * Focuses on production process * Covers the interrelation between Flash Catalyst and Photoshop/Illustrator/Flex/Flash What you'll learn Starting f

  20. Nanophase Nickel-Zirconium Alloys for Fuel Cells

    Science.gov (United States)

    Narayanan, Sekharipuram; Whitacre, jay; Valdez, Thomas

    2008-01-01

    Nanophase nickel-zirconium alloys have been investigated for use as electrically conductive coatings and catalyst supports in fuel cells. Heretofore, noble metals have been used because they resist corrosion in the harsh, acidic fuel cell interior environments. However, the high cost of noble metals has prompted a search for less-costly substitutes. Nickel-zirconium alloys belong to a class of base metal alloys formed from transition elements of widely different d-electron configurations. These alloys generally exhibit unique physical, chemical, and metallurgical properties that can include corrosion resistance. Inasmuch as corrosion is accelerated by free-energy differences between bulk material and grain boundaries, it was conjectured that amorphous (glassy) and nanophase forms of these alloys could offer the desired corrosion resistance. For experiments to test the conjecture, thin alloy films containing various proportions of nickel and zirconium were deposited by magnetron and radiofrequency co-sputtering of nickel and zirconium. The results of x-ray diffraction studies of the deposited films suggested that the films had a nanophase and nearly amorphous character.

  1. Nickel: makes stainless steel strong

    Science.gov (United States)

    Boland, Maeve A.

    2012-01-01

    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  2. Characterization of catalysts Rh and Ni/Ce{sub x}Zr{sub 1-x}O{sub 2} for hydrogen production by ethanol steam reforming; Caracterisation de catalyseurs Rhodium et Nickel/ Ce{sub x}Zr{sub 1-x}O{sub 2} pour la production d'hydrogene par vaporeformage de l'ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Birot, A

    2005-07-01

    This work concerned a study on catalytic behaviour of metallic catalysts (Rh or Ni) supported on earth rare oxides Ce{sub x}Zr{sub 1-x}O{sub 2} in ethanol steam reforming in order to produce hydrogen. Catalyst 1%Rh/Ce0,50Zr0,50O{sub 2} showed a good activity with a good hydrogen yield. We turned a study onto understanding inter-conversion reaction between H{sub 2}, CO and CO{sub 2} which lead to CH{sub 4} formation. We also studied intrinsic properties of catalysts. We confirmed basic character of catalysts and a good hydrogenation activity. A good activity in CO hydrogenation allowed to evidence a necessity to use a catalyst which is less active in hydrogenation reaction and with a basic character in order to improve hydrogen yield. (author)

  3. Nickel Excretion in Urine after Oral Administration

    DEFF Research Database (Denmark)

    Menne, T.; Mikkelsen, H. I.; Solgaard, Per Bent

    1978-01-01

    In recent years the importance of internal exposure to nickel in patients with recurrent hand eczema and nickel allergy has become evident. The present study was performed in order to investigate the value of urinary nickel determinations as an index of oral nickel intake. After oral administration...... of 5.6 mg nickel (as the sulfate), increased nickel excretion was found over the following 2-3 days. We conclude that consecutive urinary nickel determinations are able to disclose variations in oral intake of nickel....

  4. BINIVOX catalyst for hydrogen production from ethanol by low ...

    Indian Academy of Sciences (India)

    Nickel doped bismuth vanadate [Bi₄ (V₀. ₉₀Ni₀.₁₀) ₂ O₁₁ ₋ δ;BINIVOX] calcined at 800 ◦C (BINIVOX-800) catalyst is prepared by a solution combustion method. The catalytic activity study is carriedin the temperature range of 250–400 ◦C, and with the molar feed ratios of water: ethanol at 23:1 and 2.5:1. The study ...

  5. Ultrasonic preparation of nano-nickel/activated carbon composite using spent electroless nickel plating bath and application in degradation of 2,6-dichlorophenol.

    Science.gov (United States)

    Su, Jingyu; Jin, Guanping; Li, Changyong; Zhu, Xiaohui; Dou, Yan; Li, Yong; Wang, Xin; Wang, Kunwei; Gu, Qianqian

    2014-11-01

    Ni was effectively recovered from spent electroless nickel (EN) plating baths by forming a nano-nickel coated activated carbon composite. With the aid of ultrasonication, melamine-formaldehyde-tetraoxalyl-ethylenediamine chelating resins were grafted on activated carbon (MFT/AC). PdCl2 sol was adsorbed on MFT/AC, which was then immersed in spent electroless nickel plating bath; then nano-nickel could be reduced by ascorbic acid to form a nano-nickel coating on the activated carbon composite (Ni/AC) in situ. The materials present were carefully examined by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and electrochemistry techniques. The resins were well distributed on the inside and outside surfaces of activated carbon with a size of 120 ± 30 nm in MFT/AC, and a great deal of nano-nickel particles were evenly deposited with a size of 3.8 ± 1.1 nm in Ni/MFT. Moreover, Ni/AC was successfully used as a catalyst for ultrasonic degradation of 2,6-dichlorophenol. Copyright © 2014. Published by Elsevier B.V.

  6. Review of Novel Catalysts for Biomass Tar Cracking and Methane Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Mark A.

    2007-10-10

    A review of the literature was conducted to examine the performance of catalysts other than conventional nickel catalysts, and alkaline earth and olivine based catalysts for treating hot raw product gas from a biomass gasifier to convert methane and tars into synthesis gas. Metal catalysts other than Ni included precious metals Rh, Ru, Ir, Pt, and Pd, as well as Cu, Co, and Fe in limited testing. Nickel catalysts promoted with Rh, Zr, Mn, Mo, Ti, Ag, or Sn were also examined, as were Ni catalysts on Ce2O3, TiO2, ZrO2, SiO2, and La2O3. In general, Rh stood out as a consistently superior metal catalyst for methane reforming, tar cracking, and minimizing carbon buildup on the catalyst. Ru and Ir also showed significant improvement over Ni for methane reforming. Ceria stood out as good support material and particularly good promoter material when added in small quantities to another support material such as alumina, zirconia, or olivine. Other promising supports were lanthana, zirconia, and titania.

  7. Enhanced activity of Pt/CNTs anode catalyst for direct methanol fuel cells using Ni2P as co-catalyst

    Science.gov (United States)

    Li, Xiang; Luo, Lanping; Peng, Feng; Wang, Hongjuan; Yu, Hao

    2018-03-01

    The direct methanol fuel cell is a promising energy conversion device because of the utilization of the state-of-the-art platinum (Pt) anode catalyst. In this work, novel Pt/Ni2P/CNTs catalysts were prepared by the H2 reduction method. It was found that the activity and stability of Pt for methanol oxidation reaction (MOR) could be significantly enhanced while using nickel phosphide (Ni2P) nanoparticles as co-catalyst. X-ray photoelectron spectroscopy revealed that the existence of Ni2P affected the particle size and electronic distribution of Pt obviously. Pt/CNTs catalyst, Pt/Ni2P/CNTs catalysts with different Ni2P amount were synthesized, among which Pt/6%Ni2P/CNTs catalyst exhibited the best MOR activity of 1400 mAmg-1Pt, which was almost 2.5 times of the commercial Pt/C-JM catalyst. Moreover, compared to other Pt-based catalysts, this novel Pt/Ni2P/CNTs catalyst also exhibited higher onset current density and better steady current density. The result of this work may provide positive guidance to the research on high efficiency and stability of Pt-based catalyst for direct methanol fuel cells.

  8. Strategies for improving the performance and stability of Ni-based catalysts for reforming reactions.

    Science.gov (United States)

    Li, Shuirong; Gong, Jinlong

    2014-11-07

    Owing to the considerable publicity that has been given to petroleum related economic, environmental, and political problems, renewed attention has been focused on the development of highly efficient and stable catalytic materials for the production of chemical/fuel from renewable resources. Supported nickel nanoclusters are widely used for catalytic reforming reactions, which are key processes for generating synthetic gas and/or hydrogen. New challenges were brought out by the extension of feedstock from hydrocarbons to oxygenates derivable from biomass, which could minimize the environmental impact of carbonaceous fuels and allow a smooth transition from fossil fuels to a sustainable energy economy. This tutorial review describes the recent efforts made toward the development of nickel-based catalysts for the production of hydrogen from oxygenated hydrocarbons via steam reforming reactions. In general, three challenges facing the design of Ni catalysts should be addressed. Nickel nanoclusters are apt to sinter under catalytic reforming conditions of high temperatures and in the presence of steam. Severe carbon deposition could also be observed on the catalyst if the surface carbon species adsorbed on metal surface are not removed in time. Additionally, the production of hydrogen rich gas with a low concentration of CO is a challenge using nickel catalysts, which are not so active in the water gas shift reaction. Accordingly, three strategies were presented to address these challenges. First, the methodologies for the preparation of highly dispersed nickel catalysts with strong metal-support interaction were discussed. A second approach-the promotion in the mobility of the surface oxygen-is favored for the yield of desired products while promoting the removal of surface carbon deposition. Finally, the process intensification via the in situ absorption of CO2 could produce a hydrogen rich gas with low CO concentration. These approaches could also guide the design

  9. Nickel, cobalt, and their alloys

    CERN Document Server

    2000-01-01

    This book is a comprehensive guide to the compositions, properties, processing, performance, and applications of nickel, cobalt, and their alloys. It includes all of the essential information contained in the ASM Handbook series, as well as new or updated coverage in many areas in the nickel, cobalt, and related industries.

  10. Catalytic oxidation of sulfide ions over nickel hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, A.; Khristov, P. [Institute of Catalysis, Bulgarian Academy of Sciences, Sofia (Bulgaria); Losev, A. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia (Bulgaria)

    1996-01-18

    The catalytic sulfide ion oxidation by oxygen to elemental sulfur over {beta}-Ni(OH){sub 2} and LiNiO{sub 2} has been studied. As a result of experimental investigation performed, a reaction mechanism is suggested which involves heterogeneous and homogeneous processes. Dioxygen activation in the heterogeneous process proceeds via a redox Ni{sup 2+} <-> Ni{sup 3+} transition and participation of OH{sup -} groups. The active HO{sup -}{sub 2} species thus formed carries on the reaction in homogeneous phase. Nickel hydroxides are promising catalysts for practical application

  11. Characterization and assessment of dermal and inhalable nickel exposures in nickel production and primary user industries.

    Science.gov (United States)

    Hughson, G W; Galea, K S; Heim, K E

    2010-01-01

    The aim of this study was to measure the levels of nickel in the skin contaminant layer of workers involved in specific processes and tasks within the primary nickel production and primary nickel user industries. Dermal exposure samples were collected using moist wipes to recover surface contamination from defined areas of skin. These were analysed for soluble and insoluble nickel species. Personal samples of inhalable dust were also collected to determine the corresponding inhalable nickel exposures. The air samples were analysed for total inhalable dust and then for soluble, sulfidic, metallic, and oxidic nickel species. The workplace surveys were carried out in five different workplaces, including three nickel refineries, a stainless steel plant, and a powder metallurgy plant, all of which were located in Europe. Nickel refinery workers involved with electrolytic nickel recovery processes had soluble dermal nickel exposure of 0.34 microg cm(-2) [geometric mean (GM)] to the hands and forearms. The GM of soluble dermal nickel exposure for workers involved in packing nickel salts (nickel chloride hexahydrate, nickel sulphate hexahydrate, and nickel hydroxycarbonate) was 0.61 microg cm(-2). Refinery workers involved in packing nickel metal powders and end-user powder operatives in magnet production had the highest dermal exposure (GM = 2.59 microg cm(-2) soluble nickel). The hands, forearms, face, and neck of these workers all received greater dermal nickel exposure compared with the other jobs included in this study. The soluble nickel dermal exposures for stainless steel production workers were at or slightly above the limit of detection (0.02 microg cm(-2) soluble nickel). The highest inhalable nickel concentrations were observed for the workers involved in nickel powder packing (GM = 0.77 mg m(-3)), although the soluble component comprised only 2% of the total nickel content. The highest airborne soluble nickel exposures were associated with refineries using

  12. Preparation of Nickel/Active Carboncatalyst and its Utilization for Benzene Hydrogenation

    Directory of Open Access Journals (Sweden)

    Enggelena Septiawati

    2010-06-01

    Full Text Available The research on the preparation of nickel catalyst impregnated on active carbon by two methods has been carried out. The impregnation of Ni metal was done using nickel(II chloride as a precursor. The impregnated of Ni metal on samples in A method was made in varying of percentage i.e., 0.5, 1.0 and 2.0% (w/w as the weight proportion of Ni to active carbon and NiCl2.6H20. The concentration of Ni that would be impregnated on samples in B method was made close to Ni content of samples in A method determined by atomic adsorption spectrometry. Preparation of nickel/active carbon catalyst with A method was done with dipping the active carbon in the nickel(II chloride solution followed by filtering and then drying at 110 °C for 4 hours, and then calcination by flowing nitrogen and reduction by hydrogen, each at 400 °C at 4 hours. The treatments made on samples in A method was also done on samples in B method, the only difference was evaporating all of precursor solution after dipping active carbon in that precursor solution was done in B method. The characterization includes: iodium adsorption test, determination of nickel content by means of atomic adsorption spectrometry, and acidity by adsorption of ammonia methods. Test of catalyst activity was done by means of hydrogenation of benzene to cyclohexane at 150, 200 and 250 °C, the pressure of 1 atm and the flow rate of hydrogen 6 mL/minute. The products were analyzed by gas chromatographic method. The results show that A method produced a catalyst with relatively low nickel content. However the acidity and ability to convert benzene to cyclohexane were relatively high and it increased as increasing the content of nickel. The temperature of the reaction was achieved at 250 °C which gave the yield on conversion of 25.3678%. The catalyst obtained by B method in the same condition of hydrogenation gave only smaller results.

  13. Influence of iron doping on tetravalent nickel content in catalytic oxygen evolving films

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nancy; Bediako, D. Kwabena; Hadt, Ryan G.; Hayes, Dugan; Kempa, Thomas J.; von Cube, Felix; Bell, David C.; Chen, Lin X.; Nocera, Daniel G.

    2017-01-30

    Iron doping of nickel oxide films results in enhanced activity for promoting the oxygen evolution reaction (OER). Whereas this enhanced activity has been ascribed to a unique iron site within the nickel oxide matrix, we show here that Fe doping influences the Ni valency. The percent of Fe3+ doping promotes the formation of formal Ni4+, which in turn directly correlates with an enhanced activity of the catalyst in promoting OER. The role of Fe3+ is consistent with its behavior as a superior Lewis acid.

  14. Elaboration of nickel-impregnated over hexagonal mesoporous materials and their catalytic application

    Directory of Open Access Journals (Sweden)

    M. Laribi

    2016-11-01

    Full Text Available Hexagonal mesoporous silicas with different nickel contents have been synthesized and characterized by several techniques such as N2 physical adsorption, elemental analysis, XRD, TEM and temperature programmed reduction (TPR. In fact, the nickel-impregnated over hexagonal mesoporous silicas showed both high activity and high selectivity for Friedel–Crafts alkylations of benzene with benzyl chloride. The kinetics of the reaction over these catalysts have been investigated and the reaction has been extended to other substrates like toluene, p-xylene, anisole, naphthalene and methylnaphthalene.

  15. Phosphonium Salts as Pseudohalides: Regioselective Nickel-Catalyzed Cross-Coupling of Complex Pyridines and Diazines.

    Science.gov (United States)

    Zhang, Xuan; McNally, Andrew

    2017-08-07

    Heterobiaryls are important pharmacophores that are challenging to prepare by traditional cross-coupling methods. An alternative approach is presented where pyridines and diazines are converted into heteroaryl phosphonium salts and coupled with aryl boronic acids. Nickel catalysts are unique for selective heteroaryl transfer, and the reaction has a broad substrate scope that includes complex pharmaceuticals. Phosphonium ions also display orthogonal reactivity in cross-couplings compared to halides, enabling chemoselective palladium- and nickel-catalyzed coupling sequences. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. NiO-PTA supported on ZIF-8 as a highly effective catalyst for hydrocracking of Jatropha oil

    Science.gov (United States)

    Liu, Jing; He, Jing; Wang, Luying; Li, Rong; Chen, Pan; Rao, Xin; Deng, Lihong; Rong, Long; Lei, Jiandu

    2016-01-01

    Nickel oxide (NiO) and phosphotungstic acid (PTA) supported on a ZIF-8 (NiO-PTA/ZIF-8) catalyst was first synthesized and it showed high activity and good selectivity for the hydrocracking of Jatropha oil. The catalyst was characterized by SEM, SEM-EDS, TEM, N2 adsorption, FT-IR, XRD and XPS. Compared with the NiO-PTA/Al2O3 catalyst, the selectivity of C15-C18 hydrocarbon increased over 36%, and catalytic efficiency increased 10 times over the NiO-PTA/ZIF-8 catalyst. The prepared NiO-PTA/ZIF-8 catalyst was stable for a reaction time of 104 h and the kinetic behavior was also analyzed. This catalyst was found to bypass the presulfurization process, showing promise as an alternative to sulfided catalysts for green diesel production. PMID:27020579

  17. Rapid accurate analysis of metal (oxide)-on-silica catalysts by atomic absorption spectrometry

    NARCIS (Netherlands)

    Jütte, B.A.H.G.; Heikamp, A.; Agterdenbos, J.

    1979-01-01

    The catalysts, which contain 10–60% copper, chromium, nickel and silicon, are decomposed in sealed Teflon-lined vessels and analyzed by atomic absorption spectrometry. Matrix matching and bracketing standards are applied. The RSD of a single determination is about 1% for all components.

  18. Studies on the promotion of nickel—alumina coprecipitated catalysts: III. Cerium oxide

    NARCIS (Netherlands)

    Lansink Rotgerink, H.G.J.; Slaa, J.C.; van Ommen, J.G.; Ross, J.R.H.

    1988-01-01

    Three series of cerium-promoted nickel—alumina catalysts with different nickel-to-aluminium ratios each containing different amounts of cerium have been prepared and characterized. The calcination and reduction behaviour were found not to be altered by the presence of cerium. Part of the promoter

  19. Studies on the promotion of nickel—alumina coprecipitated catalysts: II. Lanthanum oxide

    NARCIS (Netherlands)

    Lansink Rotgerink, H.G.J.; Paalman, R.P.A.M.; van Ommen, J.G.; Ross, J.R.H.

    1988-01-01

    Two series of lanthanum promoted nickel—alumina catalysts have been prepared by coprecipitation of the metal nitrates, using potassium carbonate. The molar ratio between nickel and the sum of aluminium and lanthanum was kept constant at 2.5 or 9.0 within each series. The calcination and reduction of

  20. Nickel-Catalyzed Suzuki-Miyaura Cross-Coupling in a Green Alcohol Solvent for an Undergraduate Organic Chemistry Laboratory

    Science.gov (United States)

    Hie, Liana; Chang, Jonah J.; Garg, Neil K.

    2015-01-01

    A modern undergraduate organic chemistry laboratory experiment involving the Suzuki-Miyaura coupling is reported. Although Suzuki-Miyaura couplings typically employ palladium catalysts in environmentally harmful solvents, this experiment features the use of inexpensive nickel catalysis, in addition to a "green" alcohol solvent. The…

  1. Cobalt and Nickel Complexes Bearing 2,6-Bis(iminophenoxy Ligands:Synthesis and Ethylene Oligomerization Study

    Directory of Open Access Journals (Sweden)

    Jian-Long Du

    2006-01-01

    Full Text Available A series of new cobalt and nickel complexes MLX2 (M = Co or Ni, X = Cl bearing 2,6-bis(iminophenoxy ligands have been synthesized. Treatment of the complexes with methylaluminoxane (MAO leads to active catalysts for ethylene oligomerization. The oligomers are olefins from C4 to C6.

  2. Catalysts for Efficient Production of Carbon Nanotubes

    Science.gov (United States)

    Sun, Ted X.; Dong, Yi

    2009-01-01

    Several metal alloys have shown promise as improved catalysts for catalytic thermal decomposition of hydrocarbon gases to produce carbon nanotubes (CNTs). Heretofore almost every experiment on the production of carbon nanotubes by this method has involved the use of iron, nickel, or cobalt as the catalyst. However, the catalytic-conversion efficiencies of these metals have been observed to be limited. The identification of better catalysts is part of a continuing program to develop means of mass production of high-quality carbon nanotubes at costs lower than those achieved thus far (as much as $100/g for purified multi-wall CNTs or $1,000/g for single-wall CNTs in year 2002). The main effort thus far in this program has been the design and implementation of a process tailored specifically for high-throughput screening of alloys for catalyzing the growth of CNTs. The process includes an integral combination of (1) formulation of libraries of catalysts, (2) synthesis of CNTs from decomposition of ethylene on powders of the alloys in a pyrolytic chemical-vapor-decomposition reactor, and (3) scanning- electron-microscope screening of the CNTs thus synthesized to evaluate the catalytic efficiencies of the alloys. Information gained in this process is put into a database and analyzed to identify promising alloy compositions, which are to be subjected to further evaluation in a subsequent round of testing. Some of these alloys have been found to catalyze the formation of carbon nano tubes from ethylene at temperatures as low as 350 to 400 C. In contrast, the temperatures typically required for prior catalysts range from 550 to 750 C.

  3. Gold Nanoparticles as the Catalyst of Single-Walled Carbon Nanotube Synthesis

    Directory of Open Access Journals (Sweden)

    Yoshikazu Homma

    2014-03-01

    Full Text Available Gold nanoparticles have been proven to act as efficient catalysts for chemical reactions, such as oxidation and hydrogen production. In this review we focus on a different aspect of the catalysis of gold nanoparticles; single-walled carbon nanotube (SWCNT synthesis. This is not a traditional meaning of catalytic reaction, but SWCNTs cannot be synthesized without nanoparticles. Previously, gold was considered as unsuitable metal species as the catalyst of SWCNT synthesis. However, gold nanoparticles with diameters smaller than 5 nm were found to effectively produce SWCNTs. We discuss the catalysis of gold and related metals for SWCNT synthesis in comparison with conventional catalysts, such as iron, cobalt, and nickel.

  4. Bioaccumulation of nickel by algae

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.K.; Wood, J.M.

    1984-02-01

    Six strains of algae and one Euglena sp. were tested for their ability to bioaccumulate nickel. Radioactive /sup 63/Ni was used together with a microplate technique to determine the conditions for nickel removal by axenic cultures of cyanobacteria, green algae, and one euglenoid. The cyanobacteria tested were found to be more sensitive to nickel toxicity than the green algae or the Euglena sp. The concentration factor (CF) for nickel was determined under a variety of conditions and found to be in the range from 0 to 3.0 x 10/sup 3/. The effect of environmental variables on nickel uptake was examined, and a striking pH effect for biaccumulation was observed, with most of the algal strains accumulating nickel optimally at approximately pH 8.0. Competition experiments for binding sites between nickel and other cations as well as with other complexing anions, showed that /sup 63/Ni uptake was affected only by cobalt and by humic acids.

  5. Ozone Decomposition on the Surface of Metal Oxide Catalyst

    Directory of Open Access Journals (Sweden)

    Batakliev Todor Todorov

    2014-12-01

    Full Text Available The catalytic decomposition of ozone to molecular oxygen over catalytic mixture containing manganese, copper and nickel oxides was investigated in the present work. The catalytic activity was evaluated on the basis of the decomposition coefficient which is proportional to ozone decomposition rate, and it has been already used in other studies for catalytic activity estimation. The reaction was studied in the presence of thermally modified catalytic samples operating at different temperatures and ozone flow rates. The catalyst changes were followed by kinetic methods, surface measurements, temperature programmed reduction and IR-spectroscopy. The phase composition of the metal oxide catalyst was determined by X-ray diffraction. The catalyst mixture has shown high activity in ozone decomposition at wet and dry O3/O2 gas mixtures. The mechanism of catalytic ozone degradation was suggested.

  6. Catalytic selectivity and H-transfer in the hydroconversion of a petroleum residue using dispersed catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Cebolla, V.L.; Membrado, L.; Vela, J.; Bacaud, R.; Rouleau, L. [Instituto de Carboquimica, Zaragoza (Spain). Dept. de Procesos Quimicos

    1995-09-01

    Hydroconversion of a deasphalted vacuum residue of a crude oil has been performed in the presence of various disposable, dispersed catalysts at low concentration (450 ppm of metal) under identical conditions: a plasma-prepared nickel-carbon catalyst, an oil-soluble molybdenum naphthenate, and a commercial nickel-molybdenum supported on alumina, in order to obtain some insight into their influence upon their mechanisms of hydrogen transfer, and to evaluate their selectivities toward the production of various hydrocarbon groups. For this last purpose, a quantitative, rapid and accurate method for hydrocarbon group type analysis has been used, based on an improved system of thin-layer chromatography with flame ionization detection. The catalysts significantly affect the quantitative distribution of hydrocarbon groups without producing new chemical families. The total hydrogen consumption is only slightly increased in the presence of these kind of catalysts. However, a different distribution of the hydrogen is achieved depending on the catalyst. Molybdenum naphthenate exhibits the higher hydrogen incorporation to its derived distillates, which in turn present significantly higher number-average molecular weight and percentage of saturates than those obtained with the other catalysts. For every catalyst studied, the more the incorporation of hydrogen in distillates, the less the production of coke and gas. Throughout this paper, the agreement between the data obtained from TLC-FID and hydrogen balance is evidenced and explained. 18 refs., 5 figs., 2 tabs.

  7. Enhanced Activity of Supported Ni Catalysts Promoted by Pt for Rapid Reduction of Aromatic Nitro Compounds

    Directory of Open Access Journals (Sweden)

    Huishan Shang

    2016-06-01

    Full Text Available To improve the activities of non-noble metal catalysts is highly desirable and valuable to the reduced use of noble metal resources. In this work, the supported nickel (Ni and nickel-platinum (NiPt nanocatalysts were derived from a layered double hydroxide/carbon composite precursor. The catalysts were characterized and the role of Pt was analysed using X-ray diffraction (XRD, high-resolution transmission electron microscopy (HRTEM, energy dispersive X-ray spectroscopy (EDS mapping, and X-ray photoelectron spectroscopy (XPS techniques. The Ni2+ was reduced to metallic Ni0 via a self-reduction way utilizing the carbon as a reducing agent. The average sizes of the Ni particles in the NiPt catalysts were smaller than that in the supported Ni catalyst. The electronic structure of Ni was affected by the incorporation of Pt. The optimal NiPt catalysts exhibited remarkably improved activity toward the reduction of nitrophenol, which has an apparent rate constant (Ka of 18.82 × 10−3 s−1, 6.2 times larger than that of Ni catalyst and also larger than most of the reported values of noble-metal and bimetallic catalysts. The enhanced activity could be ascribed to the modification to the electronic structure of Ni by Pt and the effect of exposed crystal planes.

  8. Study of the effect of various factors on liberation of Nickel nanoparticles into hydrogels based on copolymers of acrylic acid β-vyniloxyethylamide with acrylic acid

    Directory of Open Access Journals (Sweden)

    A. Galieva

    2012-03-01

    Full Text Available The article considers the influence of pH and temperature on the release of nickel ions from the polymer matrix. It is established that release of metal from the polymer to the environment may be controlled by changing the external conditions. This makes possible to control the content of nickel in the environment where it can be used as a catalyst.

  9. Removing nickel from nickel-coated carbon fibers

    Science.gov (United States)

    Hardianto, A.; Hertleer, C.; De Mey, G.; Van Langenhove, L.

    2017-10-01

    Conductive fibers/yarns are one of the most important materials for smart textiles because of their electrically conductive functionality combined with flexibility and light weight. They can be applied in many fields such as the medical sector, electronics, sensors and even as thermoelectric generators. Temperature sensors, for example, can be made using the thermocouple or thermopile principle which usually uses two different metal wires that can produce a temperature-dependent voltage. However, if metal wires are inserted into a textile structure, they will decrease the flexibility properties of the textile product. Nickel-coated Carbon Fiber (NiCF), a conductive textile yarn, has a potential use as a textile-based thermopile if we can create an alternating region of carbon and nickel along the fiber which in turn it can be used for substituting the metallic thermopile. The idea was to remove nickel from NiCF in order to obtain a yarn that contains alternating zones of carbon and nickel. Due to no literature reporting on how to remove nickel from NiCF, in this paper we investigated some chemicals to remove nickel from NiCF.

  10. Characterization of Pt/HUSY and Pt-Ni/HUSY catalysts by transmission electron microscopy

    Directory of Open Access Journals (Sweden)

    Maura H. Jordão

    1999-07-01

    Full Text Available Bifunctional catalysts formed by metals (nickel, platinum as well as an association of both metals supported in an ultrastabilized Y molecular sieve (USY were prepared. The samples were obtained using a competitive ion exchange method, followed by calcination and reduction of the transition metal under hydrogen atmosphere. The solids were characterized by ICP for their chemical composition, XRD, TEM and the catalytic properties evaluated in the isomerization of the n-hexane. It was observed that the NH4USY zeolite support presented better ion exchange efficiency in comparison to that of the zeolite HUSY, due to the decrease of the pH of the reaction medium in the last case. The TEM images of the catalysts, obtained in both bright and dark field, showed that the metal particles are dispersed almost inside the molecular sieve micro and mesopores. TEM images of the catalysts obtained in bright field showed that the average particle diameter were 64 and 108 Å for platinum and nickel respectively and about 70 Å when both metals are present. In the mentioned reaction, platinum catalysts were more active and stable than the nickel ones and the catalysts formed by both metals (0,2%Pt + 0,8% Ni/HUSY presented the highest activity.

  11. Catalyst Alloys Processing

    Science.gov (United States)

    Tan, Xincai

    2014-10-01

    Catalysts are one of the key materials used for diamond formation at high pressures. Several such catalyst products have been developed and applied in China and around the world. The catalyst alloy most widely used in China is Ni70Mn25Co5 developed at Changsha Research Institute of Mining and Metallurgy. In this article, detailed techniques for manufacturing such a typical catalyst alloy will be reviewed. The characteristics of the alloy will be described. Detailed processing of the alloy will be presented, including remelting and casting, hot rolling, annealing, surface treatment, cold rolling, blanking, finishing, packaging, and waste treatment. An example use of the catalyst alloy will also be given. Industrial experience shows that for the catalyst alloy products, a vacuum induction remelt furnace can be used for remelting, a metal mold can be used for casting, hot and cold rolling can be used for forming, and acid pickling can be used for metal surface cleaning.

  12. Alloy catalyst material

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a novel alloy catalyst material for use in the synthesis of hydrogen peroxide from oxygen and hydrogen, or from oxygen and water. The present invention also relates to a cathode and an electrochemical cell comprising the novel catalyst material, and the process use...... of the novel catalyst material for synthesising hydrogen peroxide from oxygen and hydrogen, or from oxygen and water....

  13. Nanoscale nickel oxide/nickel heterostructures for active hydrogen evolution electrocatalysis

    National Research Council Canada - National Science Library

    Gong, Ming; Zhou, Wu; Tsai, Mon-Che; Zhou, Jigang; Guan, Mingyun; Lin, Meng-Chang; Zhang, Bo; Hu, Yongfeng; Wang, Di-Yan; Yang, Jiang; Pennycook, Stephen J; Hwang, Bing-Joe; Dai, Hongjie

    2014-01-01

    .... Here we report nanoscale nickel oxide/nickel heterostructures formed on carbon nanotube sidewalls as highly effective electrocatalysts for hydrogen evolution reaction with activity similar to platinum...

  14. Effect of preparation parameters on the microporous structure of Ni/SiO{sub 2} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Castillon, F.F.; Bodganchikova, N. [Centro de Investigacion Cientifica y de Educacion Superior, Ensenada (Mexico); Fuentes, S.; Avalos, M. [Univ. Nacional Autonoma de Mexico, Ensenada (Mexico). Inst. de Fisica

    1996-12-31

    In this work the authors report the synthesis of Ni/SiO{sub 2} catalysts promoted by group 2 (IIA) cations (calcium and barium) which are currently used as hydrogenation catalysts. The effect of the preparation parameters-aging, base agent, and type of cation, on the surface area of catalysts--is evaluated. Catalysts were prepared by precipitation of the precursor silicic acid, along with nickel nitrate and calcium and barium carbonates, with NaOH, NH{sub 4}OH and Na{sub 2}CO{sub 3} as precipitating agents. Catalysts were characterized by diffuse reflectance spectra (DRS) and by BET-surface area measurements. Results are discussed in terms of sol-gel chemistry.

  15. Electrodeposition of nanoporous nickel oxide film for electrochemical capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Mao-Sung; Huang, Yu-An; Yang, Chung-Hsien; Jow, Jiin-Jiang [Department of Chemical and Material Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807 (China)

    2007-12-15

    Nanoporous nickel oxide film is electrochemically anodic deposited onto a stainless steel substrate by a plating bath of sodium acetate, nickel sulfate, and sodium sulfate mixture at room temperature without any template or catalyst. The deposited film is highly porous and composed of interconnected nanoflakes of thickness 12-16 nm after 300 {sup circle} C annealing. Specific capacitance of the deposited film depends on the applied potential window significantly in 1 M KOH solution. Specific capacitance is much increased by increasing the upper limit potential due to the contribution of redox reaction of nickel oxide to the measured capacitance. The deposited film shows a superior performance in high-rate charge/discharge capability. Specific capacitance of the deposited electrode is 167.3Fg{sup -1} at 1Ag{sup -1} charge/discharge, and 156.6Fg{sup -1} at 16.5Ag{sup -1}. The film also shows a stable capacitance during cycling. After 5000 test cycles at current density of 4Ag{sup -1}, specific capacitance of the film is 140Fg{sup -1}, approximately 87.5% of its maximum capacitance (160Fg{sup -1}). (author)

  16. Stabilization of heavy metals on spent fluid catalytic cracking catalyst using marine clay.

    Science.gov (United States)

    Sun, D D; Tay, J H; Qian, C E; Lai, D

    2001-01-01

    Spent fluid catalytic cracking catalyst is a hazardous solid waste generated by petroleum refineries containing vanadium and nickel. The marine clay was used as a matrix to stabilize vanadium and nickel and produce bricks which were then fired at various temperatures. TCLP leaching tests indicated that stabilizing brick had low metal leaching, with a maximum of 6.4 mg/l for vanadium and 19.8 microg/l for nickel. Compressive strength of stabilizing brick was found to range between 20 N/mm2 and 47 N/mm2. It is believed that stabilization and encapsulation mechanisms are responsible for the stabilization of vanadium and nickel. Encapsulation is a process whereby the marine clay matrix forms a physical barrier around the heavy metals which are thus prevented from leaching out into the environment. Incorporation involves the formation of bonds between the marine clay matrix and the heavy metals which thus become incorporated in the clay microstructure.

  17. Hydroconversion of resids with dispersed molybdenum catalysts derived from phosphomolybdates

    Energy Technology Data Exchange (ETDEWEB)

    Demirel, B.; Givens, E.N. [University of Kentucky, Lexington, KY (USA). Center for Applied Energy Research

    2000-12-01

    Phosphomolybdic acid (PMA) and cobalt, nickel and potassium phosphomolybdates have been found very active catalyst precursors for the conversion of coal-and petroleum-derived resids when they are impregnated onto coal and Al{sub 2}O{sub 3}. They are mostly stable up to 400-450{degree}C in the presence of He and H{sub 2}, but significant change in stability occurs in the presence of H{sub 2}S transforming these materials into an active form of catalyst. Their solubility in water provides highly dispersed catalysts in the reaction media. PMA and these mibetallic materials were tested at the concentration of 15, 150 and 1500 mg Mo per kg feed for reaction times of 30 and 90 min, and compared to a commercial NiMo/Al{sub 2}O{sub 3} catalysts (AKZO-60). In the 30 min reactions, increasing Mo concentration did not provide a significant improvement in resid conversions compared to the non-catalyzed case. However, in the 90 min reactions, improvements were observed in conversion of coal and Mayan resids to distillate boiling below 525{degree}C. The results indicate that thermal reactions play an important role in the 30 min reactions, and catalytic reactions resulting in increased resid conversions become more important in the 90-min reactions. Higher conversions with nickel phosphomolybdate supported on Al{sub 2}O{sub 3} were observed with Mayan resid compared with coal resid. Nickel phosphomolybdate has been found to have promising catalytic activity for hydroconversion processes. 43 refs., 1 fig., 4 tabs.

  18. Synthesis of Nitrogen-Doped Carbon Nanocoils with Adjustable Morphology using Ni–Fe Layered Double Hydroxides as Catalyst Precursors

    Directory of Open Access Journals (Sweden)

    Tomohiro Iwasaki

    2015-01-01

    Full Text Available Nitrogen-doped carbon nanocoils (CNCs with adjusted morphologies were synthesized in a one-step catalytic chemical vapour deposition (CVD process using acetoni‐ trile as the carbon and nitrogen source. The nickel iron oxide/nickel oxide nanocomposites, which were derived from nickel–iron layered double hydroxide (LDH precur‐ sors, were employed as catalysts for the synthesis of CNCs. In this method, precursor-to-catalyst transformation, catalyst activation, formation of CNCs, and nitrogen doping were all performed in situ in a single process. The morphology (coil diameter, coil pitch, and fibre diameter and nitrogen content of the synthesized CNCs was indi‐ vidually adjusted by modulation of the catalyst composi‐ tion and CVD reaction temperature, respectively. The adjustable ranges of the coil diameter, coil pitch, fibre diameter, and nitrogen content were confirmed to be approximately 500±100 nm, 600±100 nm, 100±20 nm, and 1.1±0.3 atom%, respectively.

  19. Influence of Ligand Backbone Structure and Connectivity on the Properties of Phosphine-Sulfonate Pd(II/Ni(II Catalysts

    Directory of Open Access Journals (Sweden)

    Zixia Wu

    2017-05-01

    Full Text Available Phosphine-sulfonate based palladium and nickel catalysts have been extensively studied in ethylene polymerization and copolymerization reactions. Previously, the majority of the research works focused on the modifications of the substituents on the phosphorous atom. In this contribution, we systematically demonstrated that the change of the ligand backbone from benzene to naphthalene could greatly improve the properties of this class of catalysts. In the palladium system, this change could increase catalyst stability and polyethylene molecular weights. In the nickel system, this change could dramatically increase the polyethylene molecular weights. Most interestingly, the change in the connectivity of phosphine and sulfonate moieties to the naphthalene backbone could also significantly influence the catalyst properties.

  20. Manipulating microstructures and electrical properties of carbon fiber/reduced graphene oxide/nickel composite textiles with electrochemical deposition techniques

    Science.gov (United States)

    Cheng, Wei-Liang; Zhao, Quan-Liang; Shi, Fei

    2017-04-01

    Since graphene and their composites play significant roles in the catalysts, energy storage, electronics and other fields, where electron transport is highly critical, here, we introduce reduced graphene oxide (RGO) interfaces in the carbon fiber (CF) networks for preparing a novel lightweight carbon fiber/reduced graphene oxide/nickel (CF-RGO-Ni) composite textile. Upon the charaterizations on the microscopic morphologies, electrical and magnetic properties, and density, the presence of RGO nanosheets and nickel nanoparticles would substantially influence the related physical properties in the resulting composite textiles. Furthermore, the key parameters, including RGO loading, deposition time, current density and annealing temperature of carbon matrices, have been studied to understand their effects on the electrochemical deposition of nickel nanoparticles. Implication of the results suggests that the RGO interface is a unique medium for essentially promoting the electrochemical deposition kinetics and active sites for growing nickel nanoparticles, which indicates a universal approach for preparing advanced lightweight composites with the presence of graphene naonstructures.

  1. Catalytic role of nickel in the decarbonylative addition of phthalimides to alkynes

    KAUST Repository

    Poater, Albert

    2013-11-11

    Density functional theory calculations have been used to investigate the catalytic role of nickel(0) in the decarbonylative addition of phthalimides to alkynes. According to Kurahashi et al. the plausible reaction mechanism involves a nucleophilic attack of nickel at an imide group, giving a six-membered metallacycle, followed by a decarbonylation and insertion of an alkyne leading to a seven-membered metallacycle. Finally a reductive elimination process produces the desired product and regenerates the nickel(0) catalyst. In this paper, we present a full description of the complete reaction pathway along with possible alternative pathways, which are predicted to display higher upper barriers. Our computational results substantially confirm the proposed mechanism, offering a detailed geometrical and energetical understanding of all the elementary steps. © 2013 American Chemical Society.

  2. EPIDEMIOLOGICAL AND PATHOGENETIC ASPECTS OF NICKEL POISONING

    Directory of Open Access Journals (Sweden)

    Vladmila Bojanic

    2007-04-01

    Full Text Available Nickel is widely distributed in the environment. High consumption of nickel containing products inevitably leads to environmental pollution by nickel and its derivatives at all stages of production, utilization, and disposal.Human exposure to nickel occurs primarily via inhalation and ingestion and is particularly high among nickel metallurgy workers. In addition, implantation of nickel-containing endoprostheses and iatrogenic administration of nickel-contaminated medica-tions leads to significant parenteral exposures. Exposure to nickel compounds can produce a variety of adverse effects on human health. Nickel allergy in the form of contact dermatitis is the most common reaction.A frontal headache, vertigo, nausea, vomiting, insomnia, and irritability are the most common signs of acute poisoning with nickel compounds. The respiratory tract, kidneys and liver suffer the most significant changes like nickel pneumoconiosis, chronic rhinitis and sinonasal tumors and transitory nephropathy. Although the accumulation of nickel in the body through chronic exposure can lead to lung fibrosis, cardiovascular and kidney diseases, the most serious concerns relate to nickel’s carcinogenic activity. Nickel compounds are carcinogenic to humans and metallic nickel is possibly carcinogenic to humans.

  3. Nickel Oxide (NiO nanoparticles prepared by solid-state thermal decomposition of Nickel (II schiff base precursor

    Directory of Open Access Journals (Sweden)

    Aliakbar Dehno Khalaji

    2015-06-01

    Full Text Available In this paper, plate-like NiO nanoparticles were prepared by one-pot solid-state thermal decomposition of nickel (II Schiff base complex as new precursor. First, the nickel (II Schiff base precursor was prepared by solid-state grinding using nickel (II nitrate hexahydrate, Ni(NO32∙6H2O, and the Schiff base ligand N,N′-bis-(salicylidene benzene-1,4-diamine for 30 min without using any solvent, catalyst, template or surfactant. It was characterized by Fourier Transform Infrared spectroscopy (FT-IR and elemental analysis (CHN. The resultant solid was subsequently annealed in the electrical furnace at 450 °C for 3 h in air atmosphere. Nanoparticles of NiO were produced and characterized by X-ray powder diffraction (XRD at 2θ degree 0-140°, FT-IR spectroscopy, scanning electron microscopy (SEM and transmission electron microscopy (TEM. The XRD and FT-IR results showed that the product is pure and has good crystallinity with cubic structure because no characteristic peaks of impurity were observed, while the SEM and TEM results showed that the obtained product is tiny, aggregated with plate-like shape, narrow size distribution with an average size between 10-40 nm. Results show that the solid state thermal decomposition method is simple, environmentally friendly, safe and suitable for preparation of NiO nanoparticles. This method can also be used to synthesize nanoparticles of other metal oxides.

  4. Hydroxide catalysts for lignin depolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T.; Biddy, Mary J.; Chmely, Stephen C.; Sturgeon, Matthew

    2017-04-25

    Solid base catalysts and their use for the base-catalyzed depolymerization (BCD) of lignin to compounds such as aromatics are presented herein. Exemplary catalysts include layered double hydroxides (LDHs) as recyclable, heterogeneous catalysts for BCD of lignin.

  5. Hydroxide catalysts for lignin depolymerization

    Science.gov (United States)

    Beckham, Gregg T; Biddy, Mary J.; Kruger, Jacob S.; Chmely, Stephen C.; Sturgeon, Matthew

    2017-10-17

    Solid base catalysts and their use for the base-catalyzed depolymerization (BCD) of lignin to compounds such as aromatics are presented herein. Exemplary catalysts include layered double hydroxides (LDHs) as recyclable, heterogeneous catalysts for BCD of lignin.

  6. Nickel-resistant bacteria from anthropogenically nickel-polluted and naturally nickel-percolated ecosystems.

    Science.gov (United States)

    Stoppel, R; Schlegel, H G

    1995-06-01

    DNA fragments harboring the nickel resistance determinants from bacteria isolated from anthropogenically polluted ecosystems in Europe and Zaire were compared with those harboring the nickel resistance determinants from bacteria isolated from naturally nickel-percolated soils from New Caledonia by DNA-DNA hybridization. The biotinylated DNA probes were derived from the previously described Alcaligenes eutrophus CH34, Alcaligenes xylosoxidans 31A, Alcaligenes denitrificans 4a-2, and Klebsiella oxytoca CCUG 15788 and four new nickel resistance-determining fragments cloned from strains isolated from soils under nickel-hyperaccumulating trees. Nine probes were hybridized with endonuclease-cleaved plasmid and total DNA samples from 56 nickel-resistant strains. Some of the New Caledonian strains were tentatively identified as Acinetobacter, Pseudomonas mendocina, Comamonas, Hafnia alvei, Burkholderia, Arthrobacter aurescens, and Arthrobacter ramosus strains. The DNA of most strains showed homologies to one or several of the following nickel resistance determinants: the cnr and ncc operons of the strains A. eutrophus CH34 and A. xylosoxidans 31A, respectively, the nre operon of strain 31A, and the nickel resistance determinants of K. oxytoca. On the basis of their hybridization reactions the nickel resistance determinants of the strains could be assigned to four groups: (i) cnr/ncc type, (ii) cnr/ncc/nre type, (iii) K. oxytoca type, and (iv) others. The majority of the strains were assigned to the known groups. Among the strains from Belgium and Zaire, exclusively the cnr/ncc and the cnr/ncc/nre types were found. Among the New Caledonian strains all four types were represented. Homologies to the nre operon were found only in combination with the cnr/ncc operon. The homologies to the cnr/ncc operon were the most abundant and were detected alone or together with homologies to the nre operon. Only the DNA of the strains isolated from soil in Scotland and the United States

  7. Smart nickel oxide materials for the applications of energy efficiency and storage

    Science.gov (United States)

    Lin, Feng

    The present dissertation studies nickel oxide-based materials for the application of electrochromic windows and lithium-air batteries. The materials were fabricated via radio frequency magnetron sputtering and subsequently post-treated with thermal evaporation and ozone exposure. The strategies to improve electrochromic performance of nickel oxide materials were investigated including compositional control, morphology tuning, modification of electronic structure and interface engineering (i.e., Li2O 2, graphene). The electrochemical properties of the resulting materials were characterized in lithium ion electrolytes. Extremely high performing nickel oxide-based electrochromic materials were obtained in terms of optical modulation, switching kinetics, bleached-state transparency and durability, which promise the implementation of these materials for practical smart windows. With the aid of advanced synchrotron X-ray absorption spectroscopy, it is reported for the first time that the electrochromic effect in multicomponent nickel oxide-based materials arises from the reversible formation of hole states in the NiO6 cluster accompanying with the reversible formation of Li2O2. The reversible formation of Li2O 2 was successfully leveraged with the study of electro-catalysts and cathode materials for lithium-air batteries. The reversibility of Li 2O2 was thoroughly investigated using soft X-ray absorption spectroscopy and theoretical simulation, which substantiates the promise of using electrochromic films as electro-catalysts and/or cathode materials in lithium-air batteries.

  8. Effect of Calcination Temperature on Morphological and Topography of Nickel-Alumina Thin Film

    Directory of Open Access Journals (Sweden)

    Sarwani Khairul Ilman

    2016-01-01

    Full Text Available Dip coating process promises good potential of nickel-alumina catalyst deposition on metal substrate for various applications especially in gas conversion reaction. This study was conducted to investigate the effect of different calcination temperature on nickel-alumina catalysts thin film formation. Four different calcination temperature were used, which are 300°C, 400°C, 500°C and 600°C. The calculation process was conducted for a duration of 90 minutes. The deposited thin films were characterized using Atomic Force Microscopy (AFM and X-ray diffraction (XRD equipment. The AFM result showed that the surface roughness of the nickel-alumina increase proportionally from 56 to 275 nm when the calcination temperature increased from 300 to 600°C. From an observation at high calcination temperature, the atom of grains assisted diffusion at the crystallite point causing grain with lower surface energy become larger. As the calcination temperature increase, the surface profile becomes rough and uneven representing high surface roughness. Thus, the effect of calcination temperature greatly influences the surface roughness of the nickel-alumina thin film.

  9. Pulse reversal plating of nickel alloys

    DEFF Research Database (Denmark)

    Tang, Peter Torben

    2007-01-01

    Pulse plating has previously been reported to improve the properties of nickel and nickel alloy deposits. Typically, focus has been on properties such as grain size, hardness and smoothness. When pulse plating is to be utilised for microtechnologies such as microelectromechanical systems (MEMS......), internal stress and material distribution are even more important. With baths based upon nickel chloride, and nickel and cobalt chlorides, pulse reversal plating of both pure nickel and nickel-cobalt alloys has been used to fabricate tools for microinjection moulding. Pulse reversal plating of ternary soft...

  10. Microbial recovery of metals from spent coal liquefaction catalysts. Final and quarterly report, July 1994--September 1994

    Energy Technology Data Exchange (ETDEWEB)

    Sandbeck, K.A.; Cleveland, D.

    1995-08-01

    Research is reported on the recovery of molybdenum and nickel from spent coal liquefaction catalysts. Mo release from spent coal liquefaction catalysts has been shown to be dependent upon many parameters, but release is dominated by microbial growth. The microbial Mo release is a rapid process requiring less than one week for 90% of the releaseable Mo to be solubilized from whole washed (THF) catalyst. It could be expected that the rates would be even greater with crushed catalyst. Efforts were centered on optimizing the parameters that stimulate microbial growth and action and further efforts centered on catalyst pre-treatment prior to microbial bio-leaching. Recent experiments suggest that hydrogen peroxide promises to be an effective pre-treatment wash. Hydrogen peroxide was also found to be an effective and economical agent for metals solubilization per se and could promote solubilization without subjecting the catalyst to microbial growth.

  11. Reducible oxide based catalysts

    Science.gov (United States)

    Thompson, Levi T.; Kim, Chang Hwan; Bej, Shyamal K.

    2010-04-06

    A catalyst is disclosed herein. The catalyst includes a reducible oxide support and at least one noble metal fixed on the reducible oxide support. The noble metal(s) is loaded on the support at a substantially constant temperature and pH.

  12. Fischer-Tropsch Catalysts

    Science.gov (United States)

    White, James H. (Inventor); Taylor, Jesse W. (Inventor)

    2008-01-01

    Catalyst compositions and methods for F-T synthesis which exhibit high CO conversion with minor levels (preferably less than 35% and more preferably less than 5%) or no measurable carbon dioxide generation. F-T active catalysts are prepared by reduction of certain oxygen deficient mixed metal oxides.

  13. Catalyst for Ammonia Oxidation

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a bimetallic catalyst for ammonia oxidation, a method for producing a bimetallic catalyst for ammonia oxidation and a method for tuning the catalytic activity of a transition metal. By depositing an overlayer of less catalytic active metal onto a more catalytic...

  14. Nanostructured catalyst supports

    Science.gov (United States)

    Zhu, Yimin; Goldman, Jay L.; Qian, Baixin; Stefan, Ionel C.

    2012-10-02

    The present invention relates to SiC nanostructures, including SiC nanopowder, SiC nanowires, and composites of SiC nanopowder and nanowires, which can be used as catalyst supports in membrane electrode assemblies and in fuel cells. The present invention also relates to composite catalyst supports comprising nanopowder and one or more inorganic nanowires for a membrane electrode assembly.

  15. Catalyst Deactivation 2001

    Energy Technology Data Exchange (ETDEWEB)

    Spivey, J.J. (ed.); Roberts, G.W. (ed.) [Department of Chemical Engineering, 2401 Stinson Avenue, Riddick Engineering Labs, NC State University, Box 7905, Raleigh, NC 27695 (United States); Davis, B.H. (ed.) [University of Kentucky, Centre for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511-8433 (United States)

    2001-10-01

    Selected Papers: Maxted Award Lecture. Whisker carbon revisited (J.R. Rostrup-Nielsen, J Sehested). Carbon Deposition. Various forms of the carbonaceous deposit on the model cobalt catalyst studied in hydrogenation of ethylene (J. Lojewska). Hydrodechlorination of 1,2-dichloropropane over Pt-Cu/C catalysts: coke formation determined by a novel technique-TEOM (Weidung. Zhu et al.). Characterization of structure and combustion behavior of the coke formed on a hydroisomerization catalyst (Jin-an Wang et al.). The effects of pore structure on catalyst deactivation by coke formation (L.D.T. Camara et al.). Coke deactivation of acid sites on ZSM-5 zeolite (G.V. Echevsky et al.). Characterization of the Working Catalyst. Deactivation of a zirconia supported chromia aromatization catalyst investigated by in-situ H-D tracer experiments (H. Ehwald et al.). Deactivation/Regeneration in Environmental Processes. Study of the sintering of a DeNOx commercial catalyst (I. Nova et al.). Deactivation of chromium oxide catalyst for the removal of perchloroethylene (PCE) (Sung Dae Yim et al.). Deactivation/Regeneration in Industrial Processes. Deactivation of Pd-based combustion catalysts supported on modified alumina (P.O. Thevenin et al.). Selective acid-base poisoning on bifunctional alkylation reaction (A. Borgna et al.). Processes occurring during deactivation/regeneration of a vanadia/alumina catalyst under propane dehydrogenation conditions (S David Jackson et al.). Regeneration of supported palladium catalyst for selective hydrogenation of acetylene (L.O. Almanza, O.I. Martinez). Quinone mediated stabilization of a palladium catalyst for the synthesis of hydrogen peroxide from carbon monoxide, water and oxygen (D. Bianchi et al.). Metals on a novel USY zeolite after hydrothermal aging (Huiping Tian et al.). General Papers. Partial oxidation of toluene to benzaldehyde over vanadium antimonate catalysts doped with titanium: The influence (S. Larrondo et al.). Deactivation and

  16. Application of sodium carbonate prevents sulphur poisoning of catalysts in automated total mercury analysis

    Science.gov (United States)

    McLagan, David S.; Huang, Haiyong; Lei, Ying D.; Wania, Frank; Mitchell, Carl P. J.

    2017-07-01

    Analysis of high sulphur-containing samples for total mercury content using automated thermal decomposition, amalgamation, and atomic absorption spectroscopy instruments (USEPA Method 7473) leads to rapid and costly SO2 poisoning of catalysts. In an effort to overcome this issue, we tested whether the addition of powdered sodium carbonate (Na2CO3) to the catalyst and/or directly on top of sample material increases throughput of sulphur-impregnated (8-15 wt%) activated carbon samples per catalyst tube. Adding 5 g of Na2CO3 to the catalyst alone only marginally increases the functional lifetime of the catalyst (31 ± 4 g of activated carbon analyzed per catalyst tube) in relation to unaltered catalyst of the AMA254 total mercury analyzer (17 ± 4 g of activated carbon). Adding ≈ 0.2 g of Na2CO3 to samples substantially increases (81 ± 17 g of activated carbon) catalyst life over the unaltered catalyst. The greatest improvement is achieved by adding Na2CO3 to both catalyst and samples (200 ± 70 g of activated carbon), which significantly increases catalyst performance over all other treatments and enables an order of magnitude greater sample throughput than the unaltered samples and catalyst. It is likely that Na2CO3 efficiently sequesters SO2, even at high furnace temperatures to produce Na2SO4 and CO2, largely negating the poisonous impact of SO2 on the catalyst material. Increased corrosion of nickel sampling boats resulting from this methodological variation is easily resolved by substituting quartz boats. Overall, this variation enables an efficient and significantly more affordable means of employing automated atomic absorption spectrometry instruments for total mercury analysis of high-sulphur matrices.

  17. Propane steam reforming in micro-channels-results from catalyst screening and optimisation

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, Gunther; Zapf, Ralf; Hessel, Volker; Loewe, Holger [Chemical Process Engineering, Institut fuer Mikrotechnik Mainz GmbH, Carl-Zeiss-Str. 18-20, 55129 Mainz (Germany)

    2004-12-08

    Wash-coated alumina catalyst coatings introduced into micro-channels were applied for the steam reforming of propane with the aim of hydrogen generation for mobile fuel cell applications. Home-made rhodium, platinum, nickel and palladium catalysts were tested in a standard screening protocol at a steam to carbon ratio 1.4 and 3 temperatures (450, 550 and 650{sup o}C) at 8ms residence time in the micro-channels and compared to some commercial catalysts. Besides methane, mainly propene was formed as by-product. Rhodium was identified as the best candidate concerning selectivity and activity. The introduction of platinum as a second metallic component and of CeO{sub 2} further improved the performance of the rhodium catalyst. The calcination temperature applied during the catalyst preparation had a drastic effect on platinum catalyst activity but did hardly affect the performance of the Rh/Pt/CeO{sub 2} catalyst. At a steam to carbon ratio of 2.3 and a reaction temperature of 750{sup o}C, the Rh/Pt/CeO{sub 2} catalyst showed full conversion at a turnover frequency of 63gH{sub 2}/g catalyst and hour after 6h on stream.

  18. Electron beam application for regeneration of catalysts used in refinery cracking units

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Fernando Mantovani; Duarte, Celina Lopes; Sato, Ivone Mulako; Salvador, Vera Lucia Ribeiro; Calvo, Wilson Aparecido Parejo, E-mail: fmkondo@usp.br, E-mail: clduarte@ipen.br, E-mail: wapcalvo@ipen.br, E-mail: imsato@ipen.br, E-mail: vsalvado@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    A catalyst is a substance that alters the rate of a reaction. The process of catalysis is essential to the modern day manufacturing industry, mainly in Fluid Catalytic Cracking Process (FCC) units. However, long-term exploitation of oil and gas processing catalysts leads to formation of carbon-and sulfur-containing structures of coke and dense products on the catalyst surface. They block reactive catalyst sites and reduce the catalytic activity. The main advantage of radiation processing by electron beam (EB) and gamma rays is chain cracking reaction in crude oil. Otherwise, under exposure to ionic radiation, considerable structure modification of equilibrium silica-alumina catalyst from FCC process may occur, in addition to the removal of impurities. The conditions applied in the irradiation range (20-150 kGy) of gamma rays and electron beam were not sufficient to alter the structure of the catalyst, whether for removal of the contaminant nickel, a major contaminant of the FCC catalyst, either to rupture of the crystalline structure either for the future reutilization of chemical elements. Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRFS) analysis were used to characterize and evaluate effects of radiation processing on equilibrium catalysts purification. To evaluate and comprehend the reactive catalyst sites, Scanning Electron Microscopy (SEM) and particle size distribution analyses were carried out. (author)

  19. Life Support Catalyst Regeneration Using Ionic Liquids and In Situ Resources

    Science.gov (United States)

    Abney, Morgan B.; Karr, Laurel J.; Paley, Mark S.; Donovan, David N.; Kramer, Teersa J.

    2016-01-01

    Oxygen recovery from metabolic carbon dioxide is an enabling capability for long-duration manned space flight. Complete recovery of oxygen (100%) involves the production of solid carbon. Catalytic approaches for this purpose, such as Bosch technology, have been limited in trade analyses due in part to the mass penalty for high catalyst resupply caused by carbon fouling of the iron or nickel catalyst. In an effort to mitigate this challenge, several technology approaches have been proposed. These approaches have included methods to prolong the life of the catalysts by increasing the total carbon mass loading per mass catalyst, methods for simplified catalyst introduction and removal to limit the resupply container mass, methods of using in situ resources, and methods to regenerate catalyst material. Research and development into these methods is ongoing, but only use of in situ resources and/or complete regeneration of catalyst material has the potential to entirely eliminate the need for resupply. The use of ionic liquids provides an opportunity to combine these methods in a technology approach designed to eliminate the need for resupply of oxygen recovery catalyst. Here we describe the results of an initial feasibility study using ionic liquids and in situ resources for life support catalyst regeneration, we discuss the key challenges with the approach, and we propose future efforts to advance the technology.

  20. Initial Stages in the Formation of Nickel Phosphides.

    Science.gov (United States)

    García-Muelas, Rodrigo; Li, Qiang; López, Núria

    2017-09-25

    Metal phosphides have emerged as a new powerful class of materials that can be employed as heterogeneous catalysts in transformations mainly to generate new energy vectors and the valorization of renewables. Synthetic protocols based on wet techniques are available and are based on the decomposition of the organic layer decorating the nanoparticles. For nickel, the phosphine of choice is trioctylphosphine, and this leads to the formation of NiPx materials. However, the temperature at which the decomposition starts has been found to depend on the quality of the nickel surface. Density functional theory, DFT, holds the key to analyze the initial steps of the formation of these phosphide materials. We have found how clean nickel surfaces, either (111) or (100), readily breaks the ligand P-C bonds. This triggers the process that leads to the replacement of a surface nickel atom by P and concomintantly forms a Ni adatom on the surface surrounded by two methyl groups, thus starting the formation of the NiPx phase. The whole process requires low energies, in agreement with the low temperature found in the experiments, 150 °C. In contrast, if the surface is oxidized, the reaction does not proceed at low temperatures and oxygen vacancies need to be created first to start the P-C bond breaking on the Ni-clean patches. Our results show that the cleaner the surface is, the milder the reactions are required for the NiPx formation, and thus they pave the way for gentler synthetic protocols that can improve the control of these materials.

  1. Engineering New Catalysts for In-Process Elimination of Tars

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Larry G. [Gas Technology Inst., Des Plaines, IL (United States)

    2012-09-30

    The key objective of this project was to develop a new and more efficient methodology for engineering and economically producing optimized robust catalysts for the reduction or elimination of tars in biomass gasification. Whereas current catalyst technology typically disposes thin layers of catalytically-active material onto rigid supports via wet chemistry-based methods, this project investigated novel thermal methods for directly incorporating catalytically active materials onto robust supports as well as novel approaches for incorporating catalytically active materials on and/or within an otherwise inert refractory support material which is then subsequently formed and processed to create a catalytically-active material on all exposed surfaces. Specifically, the focus of this engineered catalyst development was on materials which were derived from, or otherwise related to, olivine-like minerals, due to the inherent attrition resistance and moderate catalytic properties exhibited by natural olivine when used in a fluidized bed biomass gasifier. Task 1 of this project successfully demonstrated the direct thermal impregnation of catalytically-active materials onto an olivine substrate, with the production of a Ni-olivine catalyst. Nickel and nickel oxide were thermally impregnated onto an olivine substrate and when reduced were shown to demonstrate improved catalytic activity over the baseline olivine material and equal the tar-decomposing performance of Ni-olivine catalysts prepared by conventional wet impregnation. Task 2 involved coordination with our subcontracted project partners to further develop and characterize catalyst formulations and to optimize activity and production methods. Within this task, several significant new materials were developed. NexTech Materials developed a sintered ceramic nickel-magnesium-silicate catalyst that demonstrated superb catalytic activity and high resistance to deactivation by H2S. Alfred University developed both supported

  2. AN ELECTROPLATING METHOD OF FORMING PLATINGS OF NICKEL, COBALT, NICKEL ALLOYS OR COBALT ALLOYS

    DEFF Research Database (Denmark)

    1997-01-01

    An electroplating method of forming platings of nickel, cobalt, nickel alloys or cobalt alloys with reduced stresses in an electrodepositing bath of the type: Watt's bath, chloride bath or a combination thereof, by employing pulse plating with periodic reverse pulse and a sulfonated naphthalene...... additive. This method makes it possible to deposit nickel, cobalt, nickel or cobalt platings without internal stresses....

  3. Recent Advances in the Synthesis and Stabilization of Nickel and Nickel Oxide Nanoparticles: A Green Adeptness

    National Research Council Canada - National Science Library

    Imran Din, Muhammad; Rani, Aneela

    2016-01-01

    .... This review also provides comparative overview of influence of chemical synthesis and green synthesis on structural properties of nickel and nickel oxide nanoparticles and their biological behavior. It concludes that green methods for synthesis of nickel and nickel oxide nanoparticles are better than chemical synthetic methods.

  4. Study of fluoride corrosion of nickel alloys

    Science.gov (United States)

    Gunther, W. H.; Steindler, M. J.

    1969-01-01

    Report contains the results of an investigation of the corrosion resistance of nickel and nickel alloys exposed to fluorine, uranium hexafluoride, and volatile fission product fluorides at high temperatures. Survey of the unclassified literature on the subject is included.

  5. Nickel hydrogen battery cell storage matrix test

    Science.gov (United States)

    Wheeler, James R.; Dodson, Gary W.

    1993-01-01

    Test were conducted to evaluate post storage performance of nickel hydrogen cells with various design variables, the most significant being nickel precharge versus hydrogen precharge. Test procedures and results are presented in outline and graphic form.

  6. Catalysts, methods of making catalysts, and methods of use

    KAUST Repository

    Renard, Laetitia

    2014-03-06

    Embodiments of the present disclosure provide for catalysts, methods of making catalysts, methods of using catalysts, and the like. In an embodiment, the method of making the catalysts can be performed in a single step with a metal nanoparticle precursor and a metal oxide precursor, where a separate stabilizing agent is not needed.

  7. Prevalence of nickel allergy in Europe following the EU Nickel Directive - a review

    DEFF Research Database (Denmark)

    Ahlström, Malin G; Thyssen, Jacob P; Menné, Torkil

    2017-01-01

    Nickel contact allergy remains a problem in EU countries, despite the EU Nickel Directive. To study the prevalence of nickel allergy in EU countries following the implementation of the EU Nickel Directive, we performed a systematic search in PubMed for studies that examined the prevalence of nickel...... allergy in EU countries published during 2005-2016. We identified 46 studies: 10 in the general population and 36 in patch tested dermatitis patients. A significantly lower prevalence of nickel allergy after than before the implementation of the EU Nickel Directive was found in women aged 18-35 years (11...

  8. Nickel may be released from laptop computers

    DEFF Research Database (Denmark)

    Jensen, Peter; Jellesen, Morten Stendahl; Møller, Per

    2012-01-01

    Consumer nickel sensitization and dermatitis is caused by prolonged or repeated skin exposure to items that release nickel, for example jewellery, belts, buttons, watches, and mobile phones (1–3). We recently described a patient in whom primary nickel contact sensitization and dermatitis develope...... following the use of an Apple laptop computer (4). To estimate nickel release from Apple laptop computers, we investigated a random sample of 20 devices....

  9. Determination of nickel in hydrogenated fats and selected chocolate bars in Czech Republic.

    Science.gov (United States)

    Dohnalova, Lucie; Bucek, Pavel; Vobornik, Petr; Dohnal, Vlastimil

    2017-02-15

    Nickel is a metal that can be present in products containing hardened edible oils, possibly as leftover catalyst from the vegetable oil hardening process. Nickel may cause toxic effects including the promotion of cancer and contact allergy. In this work, nickel content was determined in hydrogenated vegetable fats and confectionery products, made with these fats, available on the Czech market using newly developed method combining microwave digestion and graphite furnace AAS. While concentrations of 0.086±0.014mg.kg(-1) or less were found in hydrogenated vegetable fats, the Ni content in confectionery products was significantly higher, varying between 0.742±0.066 and 3.141±0.217mg.kg(-1). Based on an average consumer basket, daily intake of nickel from vegetable fats is at least twice as low as intake from confectionery products. Based on results, the levels of nickel in neither vegetable fats nor confectionery products, do not represent a significant health risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Discovery of doubly magic nickel

    CERN Document Server

    CERN. Geneva

    2000-01-01

    An experiment at the French GANIL laboratory has recently discovered a new "doubly magic" nucleus-only the tenth such isotope known to science. A collaboration of French, Polish and Romanian physicists began an experiment at GANIL in Caen, France, to search for nickel-48, the last doubly magic nucleus accessible with present methods. A primary beam of nickel-58 with an average intensity of 10 /sup 12/ ions per second and an energy of 95 MeV per nucleon hit a natural nickel target in the superconducting solenoids of the SISSI device. The proton-rich projectile fragments were selected by the USE3 separator and finally identified by their time of flight, their energy loss and their total energy in a detection set-up consisting of a microchannel plate detector and a stack of five silicon detectors. This allowed the measurement of 10 independent parameters to identify each fragment arriving at the focal plane. (0 refs).

  11. Dendritic Solidification in a Copper Nickel Alloy

    OpenAIRE

    DÜNDAR, Sacit

    2014-01-01

    The distribution of nickel in dendrite arms and in interdendritic regions of copper-10% nickel alloy solidified under production conditions designed to provide 4 different cooling rates was investigated. The results indicate that at different rates of solidification undercooling, diffusion and convection mechanisms affect the microsegregation of nickel and copper in the cast materials to various extents.

  12. Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jinlong, Lv, E-mail: ljlbuaa@126.com [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Zhongguancun Street, Haidian District, Beijing 100084 (China); State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China); Tongxiang, Liang; Chen, Wang [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Zhongguancun Street, Haidian District, Beijing 100084 (China); State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China)

    2016-03-15

    Graphical abstract: - Highlights: • Improved HER efficiency of Ni-Mo coatings was attributed to ‘cauliflower’ like microstructure. • RGO in nickel-RGO composite coating promoted refined grain and facilitated HER. • Synergistic effect between nickel and RGO facilitated HER due to large specific surface of RGO. - Abstract: The nickel, nickel-molybdenum alloy, nickel-graphite and nickel-reduced graphene oxide composite coatings were obtained by the electrodeposition technique from a nickel sulfate bath. Nanocrystalline molybdenum, graphite and reduced graphene oxide in nickel coatings promoted hydrogen evolution reaction in 0.5 M H{sub 2}SO{sub 4} solution at room temperature. However, the nickel-reduced graphene oxide composite coating exhibited the highest electrocatalytic activity for the hydrogen evolution reaction in 0.5 M H{sub 2}SO{sub 4} solution at room temperature. A large number of gaps between ‘cauliflower’ like grains could decrease effective area for hydrogen evolution reaction in slight amorphous nickel-molybdenum alloy. The synergistic effect between nickel and reduced graphene oxide promoted hydrogen evolution, moreover, refined grain in nickel-reduced graphene oxide composite coating and large specific surface of reduced graphene oxide also facilitated hydrogen evolution reaction.

  13. Influence of the nickel molybdates synthesis on the propane oxidation velocity

    Energy Technology Data Exchange (ETDEWEB)

    Sautel, M.

    1995-09-01

    The alkanes transformation into alkenes is very interesting because the alkenes are used in a lot of organic synthesis. The propene formation obtained by the propane oxidizing dehydrogenation is the first step of the acrylic acid synthesis which is a product mainly used in the textile industry. The propane partial oxidation reaction on a nickel molybdate catalyst is particularly interesting. Indeed, the reaction products contain not only propene but also acrolein and acrylic acid directly obtained from propane. In order to improve the performance data of this catalyst, the author has tried to understand the mechanism of the reaction. A kinetic study of the reaction has been realized on nickel molybdate (Ni/Mo: 0.98). To simulate the reaction, a reaction mechanism in six steps has been proposed. The limitation step can be the propane adsorption or the propane oxidation at the catalyst surface. In order to determine the synthesis influence on the catalytic properties several catalysts with a varying atomic ratio have been prepared and characterized. The best catalytic results can be correlate with the electron conductivity for the products which are rich in molybdenum. The propane partial oxidation reaction is then initiated by the molybdenum atoms reduction in the solid interstitial position. (O.M.). 49 refs., 96 figs., 21 tabs.

  14. Ni-SiO2 Catalysts for the Carbon Dioxide Reforming of Methane: Varying Support Properties by Flame Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Emma C. Lovell

    2015-03-01

    Full Text Available Silica particles were prepared by flame spray pyrolysis (FSP as a support for nickel catalysts. The impact of precursor feed rate (3, 5 and 7 mL/min during FSP on the silica characteristics and the ensuing effect on catalytic performance for the carbon dioxide, or dry, reforming of methane (DRM was probed. Increasing the precursor feed rate: (i progressively lowered the silica surface area from ≈340 m2/g to ≈240 m2/g; (ii altered the silanol groups on the silica surface; and (iii introduced residual carbon-based surface species to the sample at the highest feed rate. The variations in silica properties altered the (5 wt % nickel deposit characteristics which in turn impacted on the DRM reaction. As the silica surface area increased, the nickel dispersion increased which improved catalyst performance. The residual carbon-based species also appeared to improve nickel dispersion, and in turn catalyst activity, although not to the same extent as the change in silica surface area. The findings illustrate both the importance of silica support characteristics on the catalytic performance of nickel for the DRM reaction and the capacity for using FSP to control these characteristics.

  15. ALKALI RESISTANT CATALYST

    DEFF Research Database (Denmark)

    2008-01-01

    The present invention concerns the selective removal of nitrogen oxides (NOx) from gasses. In particular, the invention concerns a process, a catalyst and the use of a catalyst for the selective removal of nitrogen oxides in the presence of ammonia from gases containing a significant amount...... of alkali metal and/or alkali-earth compounds which process comprises using a catalyst combined of (i) a formed porous superacidic support, said superacidic support having an Hammett acidity stronger than Ho=-12, and (ii) a metal oxide catalytic component deposited on said superacidic support selected from...

  16. Nickel Aluminides for Structural Use

    Science.gov (United States)

    Liu, C. T.; Sikka, V. K.

    1986-05-01

    Nickel aluminides with the following compositions (at.%) have been developed: Ni—18±2% Al—8±2% Cr—1.0±0.8% Zr (orHf)—0.15±0.1% B. These aluminides possess superb mechanical and metallurgical properties and have potential to be used as new structural materials at elevated temperatures. This paper discusses the behavior of nickel aluminides and updates progress in developing methods of fabrication. Additional studies are expected to lead to optimum alloy compositions to further improve the creep resistance of the aluminides, particularly in wrought conditions.

  17. Platinum-nickel alloy nanoparticles supported on carbon for 3-pentanone hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Lihua, E-mail: lihuazhu@stu.xmu.edu.cn [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Zheng, Tuo; Yu, Changlin [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Zheng, Jinbao [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Tang, Zhenbiao [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Zhang, Nuowei [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Shu, Qing [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Chen, Bing H., E-mail: chenbh@xmu.edu.cn [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China)

    2017-07-01

    Highlights: • The PtNi/Ni(OH){sub 2}/C catalyst was successfully synthesized at room temperature. • PtNi alloy/C was obtained after PtNi/Ni(OH){sub 2}/C reduced in hydrogen at 300 °C. • Nanostructures of the PtNi catalysts were characterized by numerous techniques. • PtNi alloy/C exhibited high catalytic activity for 3-pentanone hydrogenation. - Abstract: In this work, we prepared the Ni/Ni(OH){sub 2}/C sample at room temperature by hydrazine hydrate reducing method. The galvanic replacement reaction method was applied to deposit platinum on the Ni/Ni(OH){sub 2} nanoparticles, to prepare the PtNi/Ni(OH){sub 2}/C catalyst. The catalyst of platinum-nickel alloy nanoparticles supported on carbon (signed as PtNi/C) was obtained by the thermal treatment of PtNi/Ni(OH){sub 2}/C in flowing hydrogen at 300 °C for 2 h. The size, nanostructure, surface properties, Pt and Ni chemical states of the PtNi/C catalyst were analyzed using powder X-ray diffraction (XRD), transmission electron microscope (TEM) and high resolution transmission electron microscope (HRTEM), high-angle annular dark-field scanning TEM (HAADF-STEM) and elemental energy dispersive X-ray spectroscopy (EDS) line scanning, X-ray photoelectron spectroscopy (XPS) and high-sensitivity low-energy ion scattering spectroscopy (HS-LEIS) techniques. The as-synthesized PtNi/C catalyst showed enhanced catalytic performance relative to the Ni/Ni(OH){sub 2}/C, Ni/C, Pt/C and PtNi/Ni(OH){sub 2}/C catalysts for 3-pentanone hydrogenation due to electron synergistic effect between Pt and Ni species in the PtNi/C catalyst. The PtNi/C catalyst also had exceling stability, with industrial application value.

  18. Orange Peel Oxidative Gasification on Ni Catalysts Promoted with CaO, CeO2 or K2O.

    Science.gov (United States)

    Vargas, G; Zapata, B; Valenzuela, M A; Alfaro, S

    2015-09-01

    Orange peel can be considered as an attractive raw material to be gasified for hydrogen or syngas production. In this work, the catalytic evaluation of several silica-supported nickel catalysts in the oxidative degradation of waste orange peel is reported. It was found that the catalytic gasification with the K2O-Ni/silica catalyst produces more hydrogen than the non-catalytic route at 600 degrees C. Surprisingly, a significant amount of ethene was obtained with the CeO2-Ni/silica catalyst, which was explained in terms of an oxidative dehydrogenation reaction of ethane formed during biomass or tar decomposition.

  19. Epoxidation catalyst and process

    Science.gov (United States)

    Linic, Suljo; Christopher, Phillip

    2010-10-26

    Disclosed herein is a catalytic method of converting alkenes to epoxides. This method generally includes reacting alkenes with oxygen in the presence of a specific silver catalyst under conditions suitable to produce a yield of the epoxides. The specific silver catalyst is a silver nanocrystal having a plurality of surface planes, a substantial portion of which is defined by Miller indices of (100). The reaction is performed by charging a suitable reactor with this silver catalyst and then feeding the reactants to the reactor under conditions to carry out the reaction. The reaction may be performed in batch, or as a continuous process that employs a recycle of any unreacted alkenes. The specific silver catalyst has unexpectedly high selectivity for epoxide products. Consequently, this general method (and its various embodiments) will result in extraordinarily high epoxide yields heretofore unattainable.

  20. Catalyst for microelectromechanical systems microreactors

    Science.gov (United States)

    Morse, Jeffrey D [Martinez, CA; Sopchak, David A [Livermore, CA; Upadhye, Ravindra S [Pleasanton, CA; Reynolds, John G [San Ramon, CA; Satcher, Joseph H [Patterson, CA; Gash, Alex E [Brentwood, CA

    2010-06-29

    A microreactor comprising a silicon wafer, a multiplicity of microchannels in the silicon wafer, and a catalyst coating the microchannels. In one embodiment the catalyst coating the microchannels comprises a nanostructured material. In another embodiment the catalyst coating the microchannels comprises an aerogel. In another embodiment the catalyst coating the microchannels comprises a solgel. In another embodiment the catalyst coating the microchannels comprises carbon nanotubes.

  1. Latent olefin metathesis catalysts

    OpenAIRE

    Monsaert, Stijn; Lozano Vila, Ana; Drozdzak, Renata; Van Der Voort, Pascal; Verpoort, Francis

    2009-01-01

    Olefin metathesis is a versatile synthetic tool for the redistribution of alkylidene fragments at carbon-carbon double bonds. This field, and more specifically the development of task-specific, latent catalysts, attracts emerging industrial and academic interest. This tutorial review aims to provide the reader with a concise overview of early breakthroughs and recent key developments in the endeavor to develop latent olefin metathesis catalysts, and to illustrate their use by prominent exampl...

  2. Heterogeneous chromium catalysts

    OpenAIRE

    2005-01-01

    The present invention relates to a heterogeneous chromium catalyst system for the polymerisation of ethylene and/or alpha olefins prepared by the steps of: (a) providing a silica-containing support, (b) treating the silica-containing support with a chromium compound to form a chromium-based silica-containing support, (c) activating the chromium-based silica-containing support, (d) chemically reducing the activated chromium-based silica-containing support to produce a precursor catalyst, (e) r...

  3. Life Cycle Assessment of Biochar versus Metal Catalysts Used in Syngas Cleaning

    Directory of Open Access Journals (Sweden)

    Robert S. Frazier

    2015-01-01

    Full Text Available Biomass gasification has the potential to produce renewable fuels, chemicals and power at large utility scale facilities. In these plants catalysts would likely be used to reform and clean the generated biomass syngas. Traditional catalysts are made from transition metals, while catalysts made from biochar are being studied. A life cycle assessment (LCA study was performed to analyze the sustainability, via impact assessments, of producing a metal catalyst versus a dedicated biochar catalyst. The LCA results indicate that biochar has a 93% reduction in greenhouse gas (GHG emissions and requires 95.7% less energy than the metal catalyst to produce. The study also estimated that biochar production would also have fewer impacts on human health (e.g., carcinogens and respiratory impacts than the production of a metal catalyst. The possible disadvantage of biochar production in the ecosystem quality is due mostly to its impacts on agricultural land occupation. Sensitivity analysis was carried out to assess environmental impacts of variability in the two production systems. In the metal catalyst manufacture, the extraction and production of nickel (Ni had significant negative effects on the environmental impacts. For biochar production, low moisture content (MC, 9% and high yield type (8 tons/acre switchgrass appeared more sustainable.

  4. Catalyst system comprising a first catalyst system tethered to a supported catalyst

    Science.gov (United States)

    Angelici, Robert J.; Gao, Hanrong

    1998-08-04

    The present invention provides new catalyst formats which comprise a supported catalyst tethered to a second and different catalyst by a suitable tethering ligand. A preferred system comprises a heterogeneous supported metal catalyst tethered to a homogeneous catalyst. This combination of homogeneous and heterogeneous catalysts has a sufficient lifetime and unusually high catalytic activity in arene hydrogenations, and potentially many other reactions as well, including, but not limited to hydroformylation, hydrosilation, olefin oxidation, isomerization, hydrocyanation, olefin metathesis, olefin polymerization, carbonylation, enantioselective catalysis and photoduplication. These catalysts are easily separated from the products, and can be reused repeatedly, making these systems very economical.

  5. Studies of supported metal catalysts. Progress report, September 1, 1980-August 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Hercules, D.M.

    1981-04-01

    During this period research has been carried out on five separate catalyst systems. The effect of zinc ions on the interaction between cobalt and ..gamma..-Al/sub 2/O/sub 3/ has been studied. Work on the oxidic Mo/Al/sub 2/O/sub 3/ system has been published and studies have been extended to the sulfided catalysts. The first phase of work on the Co/Mo/Al/sub 2/O/sub 3/ system has been completed. Work on W/Al/sub 2/O/sub 3/ catalysts has begun and the oxidic system has been studied in some detail. Work continues on metal-support interactions in supported nickel catalysts. An electron spectroscopy (ESCA) study has been completed and work is continuing on correlation of the ESCA results with measurements like temperature programmed desorption (TPD) and temperature programmed reduction (TPRd).

  6. Nickel in nails, hair and plasma from nickel-hypersensitive women

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Veien, Niels

    1990-01-01

    The concentrations of nickel in finger-nails, toe-nails, hair and plasma from 71 nickel-hypersensitive women and 20 non-hypersensitive women were determined. Nickel concentrations in finger-nails were significantly higher than in toe-nails in both the nickel-hypersensitive group and the control...... group. Nickel-sensitive women had significantly higher levels of nickel in toe-nails, hair and plasma than had control subjects, whereas there was no significant difference in nickel concentration in finger-nails between the two groups. No correlation could be demonstrated between nickel levels in any...... combination of nails, hair and plasma in the nickel-hypersensitive or in the control group....

  7. Lateritic nickel deposits of Brazil

    Science.gov (United States)

    de Oliveira, S. M. Barros; Trescases, J. J.; Melfi, A. José

    1992-03-01

    Many nickel deposits are known in Brazil, accounting for about 350 · 106 tons of ore with an average of 1.5% Ni. All are of the lateritic type. These deposits are scattered throughout the country, being rarer in the Northeastern Region and in the South, below 25 °S latitude. They are mainly associated with mafic-ultramafic massifs of large dimensions and ultramafic alkaline complexes, and occur in climatic regions of contrasting seasons. The weathering profile developed over the fresh rock consists, from bottom to top, of the following horizons: altered rock, coarse saprolite, argillaceous saprolite, ferruginous saprolite and lateritic overburden. The thickness of each horizon varies from one deposit to another, the whole profile generally exceeding 20 m. The saprolitic horizons with inherited minerals (serpentine, chlorite) or neoformed minerals (smectites) constitute the silicated nickel ore and are thicker were climatic conditions are drier; the ferruginous upper horizons made up of iron oxide-hydroxides are more developed in more humid regions. In Brazil, the silicated ore generally prevails over the oxidized ore. The main Ni-bearing minerals are serpentine, smectite, garnierite and goethite. The lateritic nickel deposits of Brazil may be correlated with two erosion surfaces, corresponding to the Sul Americano (Lower Tertiary) and Velhas (Upper Tertiary) levelling cycles. The degree of dismantling of the higher and more ancient surface and the consequent development of the Velhas Surface control the position of the nickel accumulation in the landscape. Thus, the deposits may be found either in the lowlands or in the highlands, where they are always covered by a silcrete layer. The alteration profiles in the Brazilian lateritic nickel deposits are broadly similar to those described elsewhere in the world. However, they present two characteristic features: the silicated ore prevails over the oxidized ore, and a silicified layer covers the profies developed on

  8. Catalytic deactivation on methane steam reforming catalysts. 2. Kinetic study

    Energy Technology Data Exchange (ETDEWEB)

    Agnelli, M.E.; Ponzi, E.N.; Yeramian, A.A.

    1987-08-01

    The kinetics of methane steam reforming reaction over an alumina-supported nickel catalyst was investigated at a temperature range of 640-740/sup 0/C in a flow reactor at atmospheric pressure. The experiments were performed varying the inlet concentration of methane, hydrogen, and water. A kinetic scheme of the Houghen-Watson type was satisfactorily proposed assuming the dissociative adsorption of CH/sub 4/ as the rate-limiting step, but this kinetic scheme can be easily replaced by a first-order kinetics (r/sub CH/4/sub / = kapparho/sub CH/4/sub /) for engineering purposes. Catalyst activation with H/sub 2/ and N/sub 2/ mixtures or with the reactant mixture results in the same extent of reaction.

  9. Degradation of 17α-methyltestosterone by hydroxyapatite catalyst

    Directory of Open Access Journals (Sweden)

    Daniela Langaro Savaris

    2018-02-01

    Full Text Available Fish farming is becoming a highly profitable economic activity and the rearing of fingerlings involves the practice of sex reversal for the production of species (male using the hormone 17α-methyltestosterone (MT. This study analyzed the methodology for degradation of the hormone through solar and ultraviolet radiation using hydroxyapatite (HAP as heterogeneous catalyst, synthesized by two different methods, with and without doping with nickel and copper. The results showed that MT hormone is degraded by ultraviolet or solar radiation, and accelerated in the presence of the HAP catalyst. In the presence of Fe (III in the medium, the degradation rate of the hormone decreases. The method of HAP synthesis influences the degradation efficiency.

  10. An anodic alumina supported Ni-Pt bimetallic plate-type catalysts for multi-reforming of methane, kerosene and ethanol

    KAUST Repository

    Zhou, Lu

    2014-05-01

    An anodic alumina supported Ni-Pt bimetallic plate-type catalyst was prepared by a two-step impregnation method. The trace amount 0.08 wt% of Pt doping efficiently suppressed the nickel particle sintering and improved the nickel oxides reducibility. The prepared Ni-Pt catalyst showed excellent performance during steam reforming of methane, kerosene and ethanol under both 3000 h stationary and 500-time daily start-up and shut-down operation modes. Self-activation ability of this catalyst was evidenced, which was considered to be resulted from the hydrogen spillover effect over Ni-Pt alloy. In addition, an integrated combustion-reforming reactor was proposed in this study. However, the sintering of the alumina support is still a critical issue for the industrialization of Ni-Pt catalyst. Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  11. Layered metal laurates as active catalysts in the methyl/ethyl esterification reactions of lauric acid

    Energy Technology Data Exchange (ETDEWEB)

    Lisboa, Fabio da Silva; Cordeiro, Claudiney S.; Wypych, Fernando, E-mail: wypych@ufpr.br [Centro de Pesquisas em Quimica Aplicada (CEPESQ), Departamento de Quimica, Universidade Federal do Parana, Curitiba, PR (Brazil); Gardolinski, Jose Eduardo F. da Costa [Laboratorio de Analise de Minerais e Rochas (LAMIR), Departamento de Geologia, Universidade Federal do Parana, Curitiba, PR (Brazil)

    2012-07-01

    In this work we report the synthesis, characterization and investigation of the catalytic activity of layered copper(II), manganese(II), lanthanum(III) and nickel(II) laurates in the methyl and ethyl esterification reactions of lauric acid. In the methyl esterification, conversions between 80 and 90% were observed for all catalysts, while for the ethyl esterification only manganese laurate showed reasonable catalytic activity, with conversions close to 75%. Reuse of copper and lanthanum laurates in three cycles of reaction was also investigated and both catalysts preserved the structure and retained catalytic activity close to that observed for the first reaction cycle. (author)

  12. Mesoporous molecular sieve catalysts

    DEFF Research Database (Denmark)

    Højholt, Karen Thrane

    This thesis deals with a very specific class of molecular sieves known as zeolites. Zeolites are a class of crystalline aluminosilicates characterised by pores or cavities of molecular dimensions as part of their crystal structure. In this work zeolites were modified for the use and understanding...... of different catalytic applications. Primarily the zeolites were modified regarding the porosity and the introduction of metals to the framework. The obtained materials were used as solid acid catalysts, as an inert matrix for stabilising metal nanoparticles and as an anchoring material for molecular metal...... be used as solid acid catalysts but can also be used as a size-selective matrix. It was shown that it is possible to encapsulate 1-2 nm sized gold nanoparticles by silicalite-1 or ZSM-5 zeolite crystals thereby forming a sintering-stable and substrate size-selective oxidation catalyst. After carrying out...

  13. Dynamics of Catalyst Nanoparticles

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Cavalca, Filippo; Wagner, Jakob Birkedal

    under gas exposure, dynamic phenomena such as sintering and growth can be observed with sub-Ångstrøm resolution. Metal nanoparticles contain the active sites in heterogeneous catalysts, which are important for many industrial applications including the production of clean fuels, chemicals...... and pharmaceuticals, and the cleanup of exhaust from automobiles and stationary power plants. Sintering, or thermal deactivation, is an important mechanism for the loss of catalyst activity. In order to initiate a systematic study of the dynamics and sintering of nanoparticles, various catalytic systems have been...... that particle sintering is not solely governed by the mechanisms previously proposed. These results are divided into the different phases of the catalyst lifetime....

  14. Absorption and retention of nickel from drinking water in relation to food intake and nickel sensitivity

    DEFF Research Database (Denmark)

    Nielsen, G D; Søderberg, U; Jørgensen, Poul Jørgen

    1999-01-01

    Two studies were performed to examine the influence of fasting and food intake on the absorption and retention of nickel added to drinking water and to determine if nickel sensitization played any role in this regard. First, eight nonallergic male volunteers fasted overnight before being given...... nickel in drinking water (12 micrograms Ni/kg) and, at different time intervals, standardized 1400-kJ portions of scrambled eggs. When nickel was ingested in water 30 min or 1 h prior to the meal, peak nickel concentrations in serum occurred 1 h after the water intake, and the peak was 13-fold higher...... than the one seen 1 h after simultaneous intake of nickel-containing water and scrambled eggs. In the latter case, a smaller, delayed peak occurred 3 h after the meal. Median urinary nickel excretion half-times varied between 19.9 and 26.7 h. Within 3 days, the amount of nickel excreted corresponded...

  15. Characterization and Growth Mechanism of Nickel Nanowires Resulting from Reduction of Nickel Formate in Polyol Medium

    Directory of Open Access Journals (Sweden)

    Olga A. Logutenko

    2016-01-01

    Full Text Available Nickel linear nanostructures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nanowires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nanocrystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nanowires. The possible growth processes of the wire-shaped particles taking place at 110 and 130°C are discussed. It was shown that, under certain synthesis conditions, nickel nanowires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

  16. Characterization of Nickel Diffusion and its Effect on the Microstructure of Nickel PM Steels

    Science.gov (United States)

    Tougas, Bernard; Blais, Carl; Chagnon, François; Pelletier, Sylvain

    2013-02-01

    Admixing pure elements to powder mixes can cause the formation of heterogeneous microstructures in sintered parts. For instance, nickel is renowned for forming nickel-rich areas (NRA) in powder metallurgy (PM) nickel steels due to its poor diffusivity in iron matrix (or lattice). The present work is aimed at characterizing the principal diffusion mechanisms of nickel and their influence on microstructures and properties of PM nickel steels. A new wavelength dispersive X-ray spectrometry (WDS) approach linking line scans and X-ray maps to concentration maps is proposed. Grain boundary and volume diffusion coefficients of admixed nickel have been determined in PM nickel steels using Suzuoka's equation. Results also show that nickel distributes itself in the iron matrix mainly by surface and grain boundary diffusion.

  17. Catalyst, method of making, and reactions using the catalyst

    Science.gov (United States)

    Tonkovich, Anna Lee Y [Pasco, WA; Wang, Yong [Richland, WA; Gao, Yufei [Kennewick, WA

    2002-08-27

    The present invention includes a catalyst having a layered structure with, (1) a porous support, (2) a buffer layer, (3) an interfacial layer, and optionally (4) a catalyst layer. The invention also provides a process in which a reactant is converted to a product by passing through a reaction chamber containing the catalyst.

  18. Olefin metathesis catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Kukes, S.G.; Banks, R.L.

    1986-05-20

    A process is described for preparing a disproportionation catalyst comprising admixing a catalytically effective amount of a calcined and activated catalyst consisting essentially of at least one metal oxide selected from molybdenum oxide and tungsten oxide and a support containing a major proportion of silica or alumina with a promoting amount of a methylating agent selected from the group consisting of dimethyl sulfate, dimethylsulfoxide, trimethyloxonium tetrafluorborate, methyl iodide, and methyl bromide, and subjecting same to inert atmospheric conditions for the methylating agent to promote the activity of the calcined molybdenum and tungsten oxides for the disproportionation of olefins.

  19. Fuel cell catalyst degradation

    DEFF Research Database (Denmark)

    Arenz, Matthias; Zana, Alessandro

    2016-01-01

    Fuel cells are an important piece in our quest for a sustainable energy supply. Although there are several different types of fuel cells, the by far most popular is the proton exchange membrane fuel cell (PEMFC). Among its many favorable properties are a short start up time and a high power density...... increasing focus. Activity of the catalyst is important, but stability is essential. In the presented perspective paper, we review recent efforts to investigate fuel cell catalysts ex-situ in electrochemical half-cell measurements. Due to the amount of different studies, this review has no intention to give...

  20. Market for nickel-cadmium batteries

    Science.gov (United States)

    Putois, F.

    Besides the lead/acid battery market, which has seen a tremendous development linked with the car industry, the alkaline rechargeable battery market has also been expanded for more than twenty years, especially in the field of portable applications with nickel-cadmium batteries. Today, nickel-cadmium batteries have to face newcomers on the market, such as nickel-metal hydride, which is another alkaline couple, and rechargeable lithium batteries; these new battery systems have better performances in some areas. This work illustrates the status of the market for nickel-cadmium batteries and their applications. Also, for two major applications—the cordless tool and the electric vehicles—the competitive situation of nickel-cadmium batteries; facing new systems such as nickel-metal hydride and lithium ion cells are discussed.

  1. Low patch test reactivity to nickel in unselected adolescents tested repeatedly with nickel in infancy

    DEFF Research Database (Denmark)

    Christiansen, Elisabeth Soegaard; Andersen, Klaus Ejner; Bindslev-Jensen, Carsten

    2016-01-01

    BACKGROUND: It is questionable how repeated patch tests with nickel sulphate in infancy affect nickel patch test reactivity at a later age. METHODS: The DARC cohort encompasses 562 infants invited to a clinical examination including patch tests with nickel sulphate 6 times during the first 36 mon...... an immunologic effect or the effect of nickel regulation. This article is protected by copyright. All rights reserved....

  2. Highly coke-resistant ni nanoparticle catalysts with minimal sintering in dry reforming of methane.

    Science.gov (United States)

    Han, Joung Woo; Kim, Chanyeon; Park, Jun Seong; Lee, Hyunjoo

    2014-02-01

    Nickel catalysts are typically used for hydrogen production by reforming reactions. Reforming methane with carbon dioxide, called dry reforming of methane (DRM), is a good way to produce hydrogen or syngas (a mixture of hydrogen and carbon monoxide) from two notable greenhouse gases. However, Ni catalysts used for DRM suffer from severe coke deposition. It has been known that small Ni nanoparticles are advantageous to reduce coke formation, but the high reaction temperature of DRM (800 °C) inevitably induces aggregation of the nanoparticles, leading to severe coke formation and degraded activity. Here, we develop highly coke-resistant Ni catalysts by immobilizing premade Ni nanoparticles of 5.2 nm in size onto functionalized silica supports, and then coating the Ni/SiO2 catalyst with silica overlayers. The silica overlayers enable the transfer of reactants and products while preventing aggregation of the Ni nanoparticles. The silica-coated Ni catalysts operate stably for 170 h without any degradation in activity. No carbon deposition was observed by temperature programmed oxidation (TPO), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. The Ni catalysts without silica coating show severe sintering after DRM reaction, and the formation of filamentous carbon was observed. The coke-resistant Ni catalyst is potentially useful in various hydrocarbon transformations. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Platinum Group Metal-free Catalysts for Hydrogen Evolution Reaction in Microbial Electrolysis Cells.

    Science.gov (United States)

    Yuan, Heyang; He, Zhen

    2017-07-01

    Hydrogen gas is a green energy carrier with great environmental benefits. Microbial electrolysis cells (MECs) can convert low-grade organic matter to hydrogen gas with low energy consumption and have gained a growing interest in the past decade. Cathode catalysts for the hydrogen evolution reaction (HER) present a major challenge for the development and future applications of MECs. An ideal cathode catalyst should be catalytically active, simple to synthesize, durable in a complex environment, and cost-effective. A variety of noble-metal free catalysts have been developed and investigated for HER in MECs, including Nickel and its alloys, MoS 2 , carbon-based catalysts and biocatalysts. MECs in turn can serve as a research platform to study the durability of the HER catalysts. This personal account has reviewed, analyzed, and discussed those catalysts with an emphasis on synthesis and modification, system performance and potential for practical applications. It is expected to provide insights into the development of HER catalysts towards MEC applications. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Toluene decomposition performance and NOx by-product formation during a DBD-catalyst process.

    Science.gov (United States)

    Guo, Yufang; Liao, Xiaobin; Fu, Mingli; Huang, Haibao; Ye, Daiqi

    2015-02-01

    Characteristics of toluene decomposition and formation of nitrogen oxide (NOx) by-products were investigated in a dielectric barrier discharge (DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide (MnOx), iron oxide (FeOx), cobalt oxide (CoOx) and copper oxide (CuO), supported on Al2O3/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO2 selectivity. In addition, NOx was suppressed with the decrease of specific energy density (SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the CuO catalyst showed the best performance in NOx suppression. The MnOx catalyst exhibited the lowest concentration of O3 and highest CO2 selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression. Copyright © 2014. Published by Elsevier B.V.

  5. Catalytic performance of Ni/MgO catalyst in methane dry reforming

    Science.gov (United States)

    Al-Swai, Basem M.; Osman, N. B.; Abdullah, Bawadi

    2017-10-01

    Methane dry reforming to synthesis gas over nickel catalysts supported on magnesium oxide has been studied. The support was prepared via co-precipitation method using ammonia solution (20 wt% in water) as the precipitating agent. 10 wt% of Ni metal was impregnated to form Ni/MgO catalyst. The prepared catalyst was characterized by different techniques, such as XRD, BET, SEM, and TGA analysis. The effect of reaction conditions on the conversions of CH4 and CO2, selectivity of H2 and CO, and carbon deposition were investigated in a tabular furnace reactor. The catalyst afforded as high as 93% CH4 conversion at 900 °C. The catalyst has also shown excellent stability during reaction at relatively higher space velocity (1.8×104 ml g-1 h-1) and 800 °C reaction temperature. TGA characterization of spent catalyst has shown lesser magnitude of carbon deposition on the surface of the catalyst at 900 °C.

  6. Nickel aluminide alloys with improved weldability

    Science.gov (United States)

    Santella, M.L.; Goodwin, G.M.

    1995-05-09

    Weldable nickel aluminide alloys which are essentially free, if not entirely free, of weld hot cracking are provided by employing zirconium concentrations in these alloys of greater than 2.6 wt. % or sufficient to provide a substantial presence of Ni--Zr eutectic phase in the weld so as to prevent weld hot cracking. Weld filler metals formed from these so modified nickel aluminide alloys provide for crack-free welds in previously known nickel aluminide alloys. 5 figs.

  7. Reduction of Hexavalent Chromium Using L-Cysteine Capped Nickel Nanocatalysts

    Directory of Open Access Journals (Sweden)

    Razium Ali Soomro

    2013-06-01

    Full Text Available The aim of this study was to reduce the highly toxic hexavalent chromium Cr(VI into less toxic chromium Cr(III species by using nickel nanoparticles (Ni NPs as catalysts in order to provide safety to the aqueous environment. In the first phase Ni NPs were synthesized in ethylene glycol and capped with l-cysteine by a modified microwave irradiation method using NaOH as the accelerator. The formed Ni NPs were characterized by various techniques such as UV-Visible spectroscopy, Fourier Transform Infra-red (FTIR spectroscopy and Scanning Electron Microscopy (SEM. In the second phase the formed Ni NPs were immobilized on glass surfaces and employed as catalyst for the reduction of Cr(VI ions. According to observations, 99% reduction of Cr(VI ions was achieved in the presence of 0.5 mg of Ni NPs catalyst in just five minutes as compared to nickel powder that showed only 16% reduction in 15 minutes. The study has a great impact on the aqueous pollution control of Cr(VI especially caused by the discharge of waste water from several industries utilizing Cr(VI containing salt as one of the essential gradients.

  8. A spongy nickel-organic CO2 reduction photocatalyst for nearly 100% selective CO production

    Science.gov (United States)

    Niu, Kaiyang; Xu, You; Wang, Haicheng; Ye, Rong; Xin, Huolin L.; Lin, Feng; Tian, Chixia; Lum, Yanwei; Bustillo, Karen C.; Doeff, Marca M.; Koper, Marc T. M.; Ager, Joel; Xu, Rong; Zheng, Haimei

    2017-01-01

    Solar-driven photocatalytic conversion of CO2 into fuels has attracted a lot of interest; however, developing active catalysts that can selectively convert CO2 to fuels with desirable reaction products remains a grand challenge. For instance, complete suppression of the competing H2 evolution during photocatalytic CO2-to-CO conversion has not been achieved before. We design and synthesize a spongy nickel-organic heterogeneous photocatalyst via a photochemical route. The catalyst has a crystalline network architecture with a high concentration of defects. It is highly active in converting CO2 to CO, with a production rate of ~1.6 × 104 μmol hour−1 g−1. No measurable H2 is generated during the reaction, leading to nearly 100% selective CO production over H2 evolution. When the spongy Ni-organic catalyst is enriched with Rh or Ag nanocrystals, the controlled photocatalytic CO2 reduction reactions generate formic acid and acetic acid. Achieving such a spongy nickel-organic photocatalyst is a critical step toward practical production of high-value multicarbon fuels using solar energy. PMID:28782031

  9. Flare up of Nickel Contact Dermatits Following Oral Challenge

    Directory of Open Access Journals (Sweden)

    C R Srinivas

    1988-01-01

    Full Text Available A patient having contact dermatitis due to nickel on the wrist, sides of neck, thighs and legs, confirmed by patch tests with nickel sulphate, showed aggravation of the dermatitis following oral provocation with 25 mg nickel sulphate.

  10. Metal recovery from spent refinery catalysts by means of biotechnological strategies.

    Science.gov (United States)

    Beolchini, F; Fonti, V; Ferella, F; Vegliò, F

    2010-06-15

    A bioleaching study aimed at recovering metals from hazardous spent hydroprocessing catalysts was carried out. The exhaust catalyst was rich in nickel (4.5 mg/g), vanadium (9.4 mg/g) and molybdenum (4.4 mg/g). Involved microorganisms were iron/sulphur oxidizing bacteria. Investigated factors were elemental sulphur addition, ferrous iron addition and actions contrasting a possible metal toxicity (either adding powdered activated charcoal or simulating a cross current process by means of periodical filtration). Ferrous iron resulted to be essential for metal extraction: nickel and vanadium extraction yields were 83% and 90%, respectively, while about 50% with no iron. The observed values for molybdenum extraction yields were not as high as Ni and V ones (the highest values were around 30-40%). The investigated actions aimed at contrasting a possible metal toxicity resulted not to be effective; in contrast, sequential filtration of the liquor leach had a significant negative effect on metals extraction. Nickel and vanadium dissolution kinetics resulted to be significantly faster than molybdenum dissolution ones. Furthermore, a simple first order kinetic model was successfully fitted to experimental data. All the observed results supported the important role of the indirect mechanism in bioleaching of LC-Finer catalysts. Copyright 2010 Elsevier B.V. All rights reserved.

  11. Synthesis of MWCNTs Using Monometallic and Bimetallic Combinations of Fe, Co and Ni Catalysts Supported on Nanometric SiC via TCVD

    Directory of Open Access Journals (Sweden)

    F. Shahi

    2015-04-01

    Full Text Available Nanometric Carbid Silicon (SiC supported monometallic and bimetallic catalysts containing Fe, Co, Ni transition metals were prepared by wet impregnation method. Multiwall carbon nanotubes (MWCNTs were synthesized over the prepared catalysts from catalytic decomposition of acetylene at 850°C by thermal chemical vapor deposition (TCVD technique. The synthesized nanomaterials (catalysts and CNTs were characterized by X-ray diffraction (XRD, Scanning Electron Microscopy (SEM, Transmission Electron Microscopy (TEM and Raman spectroscopy. In this paper, using of nanometric SiC powder as catalyst support was examined and the effect of applied catalyst type on characteristics of grown CNTs was investigated. The results revealed that iron, cobalt and nickel are in oxide, cobalt ferrite (CoFe2O4 and nickel ferrite (NiFe2O4 forms and nanometric SiC powder can be applied as an appropriate catalyst support in CNT growth process. It was observed that the produced CNTs on bimetallic Fe-Co possess smaller average diameter, less amorphous carbon and denser morphology compared to other binary metallic combinations. It was found that the catalytic activity of bimetallic composition decreased in the order of Fe-Co> Fe-Ni> Co-Ni. Furthermore, the monometallic Fe catalyst has the most catalytic activity compared to monometallic Co and Ni catalysts.

  12. Repeated patch testing to nickel during childhood do not induce nickel sensitization

    DEFF Research Database (Denmark)

    Søgaard Christiansen, Elisabeth

    2014-01-01

    chamber was negative. The objective of this study is to follow-up on infants with suspected nickel sensitivity. Methods: A total of 562 infants were included in the cohort and patch tested with nickel sulphate. The 26 children with a positive patch test to nickel sulphate at 12 and 18 months were offered...

  13. One Step Formation of Propene from Ethene or Ethanol through Metathesis on Nickel Ion-loaded Silica

    Directory of Open Access Journals (Sweden)

    Masakazu Iwamoto

    2011-09-01

    Full Text Available Increased propene production is presently one of the most significant objectives in petroleum chemistry. Especially the one-step conversion of ethene to propene (ETP reaction, 3C2H4 ® 2C3H6 is the most desired process. In our efforts, nickel ion-loaded mesoporous silica could turn a new type of ETP reaction into reality. The one-step conversion of ethene was 68% and the propene selectivity was 48% in a continuous gas-flow system at 673 K and atmospheric pressure. The reactivity of lower olefins and the dependences of the ETP reaction on the contact time and the partial pressure of ethene were consistent with a reaction mechanism involving dimerization of ethene to 1-butene, isomerization of 1-butene to 2-butene, and metathesis of 2-butene and ethene to yield propene. The reaction was then expanded to an ethanol-to-propene reaction on the same catalyst, in which two possible reaction routes are suggested to form ethene from ethanol. The catalysts were characterized mainly by EXAFS and TPR techniques. The local structures of the nickel species active for the ETP reaction were very similar to that of layered nickel silicate, while those on the inert catalysts were the same as that of NiO particles. 

  14. Aluminium and nickel in human albumin solutions

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Sandberg, E

    1989-01-01

    Five different brands of commercially available human albumin solutions for infusion were analysed for their aluminium and nickel contents by atomic absorption spectrometry. The aluminium concentrations ranged from 12 micrograms/l to 1109 micrograms/l and the nickel concentrations ranged from 17...... micrograms/l to 77 micrograms/l. Examination of the aluminium and nickel contents of the constituents for the production of one brand showed too low levels to explain the final contamination of the product. By following the aluminium and nickel concentrations of the same brand during the production...

  15. Sixtieth Anniversary of Ziegler-Natta Catalysts and Stereospecific Polymerization

    Directory of Open Access Journals (Sweden)

    Janović Z.

    2015-07-01

    , a new family of transition metal complexes known as metallocene catalysts were discovered, based on biscyclopentadienyl and transition metal as Zr, Hf and Ti and appropriate cocatalysts. There major advantage is solubility, high catalytic activity, and the easy tailoring of the polymer microstructure. In 1986, the first synthesis of syndiotactic polystyrene was performed using monocyclopentadienyl/titanium chloride catalyst. The development of catalysts based on diimine complexes of nickel and palladium, and of phenoxy-imino complexes of zirconium and nickel, resulted in polyolefins of different structure and morphology, and many new copolymers of ethylene particularly with polar monomers, producing a variety of new functional polymers, reactive oligomers, and block copolymers. The described discoveries of organometallic catalysts and their applications are one of the most valid models and sources of inspiration for the progress in chemistry and chemical engineering.

  16. Deactivation-resistant catalyst for selective catalyst reduction of NOx

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a catalyst for selective catalytic reduction of NOx in alkali metal containing flue gas using ammonia as reductant, the catalyst comprising a surface with catalytically active sites, wherein the surface is at least partly coated with a coating comprising at least...... one metal oxide. In another aspect the present invention relates to the use of said catalyst and to a method of producing said catalyst. In addition, the present invention relates to a method of treating an catalyst for conferring thereon an improved resistance to alkali poisoning....

  17. Liquid and Gaseous Fuel from Waste Plastics by Sequential Pyrolysis and Catalytic Reforming Processes over Indonesian Natural Zeolite Catalysts

    Directory of Open Access Journals (Sweden)

    Mochamad Syamsiro

    2014-08-01

    Full Text Available In this study, the performance of several differently treated natural zeolites in a sequential pyrolysis and catalytic reforming of plastic materials i.e. polypropylene (PP and polystyrene (PS were investigated. The experiments were carried out on two stage reactor using semi-batch system. The samples were degraded at 500°C in the pyrolysis reactor and then reformed at 450°C in the catalytic reformer. The results show that the mordenite-type natural zeolites could be used as efficient catalysts for the conversion of PP and PS into liquid and gaseous fuel. The treatment of natural zeolites in HCl solution showed an increase of the surface area and the Si/Al ratio while nickel impregnation increased the activity of catalyst. As a result, liquid product was reduced while gaseous product was increased. For PP, the fraction of gasoline (C5-C12 increased in the presence of catalysts. Natural zeolite catalysts could also be used to decrease the heavy oil fraction (>C20. The gaseous products were found that propene was dominated in all conditions. For PS, propane and propene were the main components of gases in the presence of nickel impregnated natural zeolite catalyst. Propene was dominated in pyrolysis over natural zeolite catalyst. The high quality of gaseous product can be used as a fuel either for driving gas engines or for dual-fuel diesel engine.

  18. Polymerization of ethylene in blocks with catalyst mixture; Polimerizacao de etileno em blocos por meio de mistura catalitica

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Mixture of two catalysts in one reactor for ethylene/{alpha}-olefin copolymerization results in the combination of properties of both catalysts, and thus the synthesis of a novel polymer microstructure characterized by sequences of monomers produced with each catalyst. Adding a reversible transfer agent (CSA) to the binary system enables the production of new block copolymers with enhanced properties. Late transition metal catalysts, such as {alpha}-diimine nickel catalyst when activated with MAO show high activity towards olefin polymerization. This paper describes the syntheses of PE with amorphous and crystalline blocks using a binary mixture containing a nickel catalyst with {alpha}-diimine ligand which produces highly branched polyethylene (soft PE) and a metallocene (rac-ethylenebis(H{sub 4}-indenyl)ZrCl{sub 2}) that converts ethylene into polyethylene with high activities and melting temperatures (hard PE). The influence of polymerization temperature and CSA concentration were investigated. The polymeric materials were characterized by density, thermal properties and X-ray diffractometry. (author)

  19. Salesperson, Catalyst, Manager, Leader.

    Science.gov (United States)

    Worth, Michael J.; Asp, James W., II

    1996-01-01

    This article examines four roles of the college or university development officer: salesperson (when direct solicitation is seen as the officer's primary role); catalyst (or sales manager, adviser, expert, facilitator); manager (stressing the importance of the overall office functioning); and leader (who exerts a leadership role in the…

  20. Heterogeneous chromium catalysts

    NARCIS (Netherlands)

    2005-01-01

    The present invention relates to a heterogeneous chromium catalyst system for the polymerisation of ethylene and/or alpha olefins prepared by the steps of: (a) providing a silica-containing support, (b) treating the silica-containing support with a chromium compound to form a chromium-based

  1. Olefin metathesis and catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Kukes, S. G.; Banks, R. L.

    1985-05-14

    Olefins are converted into other olefins having different numbers of carbon atoms by contact with a catalyst comprising an inorganic refractory oxide support containing at least one of tungsten oxide and molybdenum oxide and a promoting amount of at least one methylating agent under conditions suitable for the methylating agent compounds to promote the activity of tungsten and molybdenum oxides for the disproportionation reaction.

  2. Sabatier Catalyst Poisoning Investigation

    Science.gov (United States)

    Nallette, Tim; Perry, Jay; Abney, Morgan; Knox, Jim; Goldblatt, Loel

    2013-01-01

    The Carbon Dioxide Reduction Assembly (CRA) on the International Space Station (ISS) has been operational since 2010. The CRA uses a Sabatier reactor to produce water and methane by reaction of the metabolic CO2 scrubbed from the cabin air and the hydrogen byproduct from the water electrolysis system used for metabolic oxygen generation. Incorporating the CRA into the overall air revitalization system has facilitated life support system loop closure on the ISS reducing resupply logistics and thereby enhancing longer term missions. The CRA utilizes CO2 which has been adsorbed in a 5A molecular sieve within the Carbon Dioxide Removal Assembly, CDRA. There is a potential of compounds with molecular dimensions similar to, or less than CO2 to also be adsorbed. In this fashion trace contaminants may be concentrated within the CDRA and subsequently desorbed with the CO2 to the CRA. Currently, there is no provision to remove contaminants prior to entering the Sabatier catalyst bed. The risk associated with this is potential catalyst degradation due to trace organic contaminants in the CRA carbon dioxide feed acting as catalyst poisons. To better understand this risk, United Technologies Aerospace System (UTAS) has teamed with MSFC to investigate the impact of various trace contaminants on the CRA catalyst performance at relative ISS cabin air concentrations and at about 200/400 times of ISS concentrations, representative of the potential concentrating effect of the CDRA molecular sieve. This paper summarizes our initial assessment results.

  3. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  4. Synthesis of supported catalysts

    NARCIS (Netherlands)

    Jong, Krijn P. de

    1999-01-01

    Research reports on the synthesis of supported catalysts during the review period (1997-1998) have shown the use of carbon nanotubes and new hetropolyanions as examples of novel supports and of novel precursors of active components, respectively. Studies of absorption and precipitation chemistry

  5. Synthesis of the catalyst

    Indian Academy of Sciences (India)

    Admin

    50 585; Duan Y C, Ma Y C, Zhang E, Shi X J, Wang M M, Ye X W and Liu H M 2013 Design and synthesis of novel 1,2,3-triazole-dithiocarbamate hybrids as ... M, Minato T, Bao M and Yamamoto Y 2011 Nanoporous Copper Metal Catalyst in Click Chemistry: Nanoporosity-Dependent Activity without Supports and Bases; ...

  6. Catalysts for Environmental Remediation

    DEFF Research Database (Denmark)

    Abrams, B. L.; Vesborg, Peter Christian Kjærgaard

    2013-01-01

    The properties of catalysts used in environmental remediation are described here through specific examples in heterogeneous catalysis and photocatalysis. In the area of heterogeneous catalysis, selective catalytic reduction (SCR) of NOx was used as an example reaction with vanadia and tungsta...

  7. Systemic contact dermatitis after oral exposure to nickel

    DEFF Research Database (Denmark)

    Jensen, Christian Stab; Menné, Torkil; Johansen, Jeanne Duus

    2006-01-01

    Systemic contact dermatitis can be elicited experimentally in nickel-sensitive individuals by oral nickel exposure. A crucial point interpreting such experiments has been the relevance of nickel exposure from drinking water and diet. The aim of this meta-analysis study on former nickel-exposure i......Systemic contact dermatitis can be elicited experimentally in nickel-sensitive individuals by oral nickel exposure. A crucial point interpreting such experiments has been the relevance of nickel exposure from drinking water and diet. The aim of this meta-analysis study on former nickel...

  8. Catalyst support structure, catalyst including the structure, reactor including a catalyst, and methods of forming same

    Science.gov (United States)

    Van Norman, Staci A.; Aston, Victoria J.; Weimer, Alan W.

    2017-05-09

    Structures, catalysts, and reactors suitable for use for a variety of applications, including gas-to-liquid and coal-to-liquid processes and methods of forming the structures, catalysts, and reactors are disclosed. The catalyst material can be deposited onto an inner wall of a microtubular reactor and/or onto porous tungsten support structures using atomic layer deposition techniques.

  9. Nb effect in the nickel oxide-catalyzed low-temperature oxidative dehydrogenation of ethane

    KAUST Repository

    Zhu, Haibo

    2012-01-01

    A method for the preparation of NiO and Nb-NiO nanocomposites is developed, based on the slow oxidation of a nickel-rich Nb-Ni gel obtained in citric acid. The resulting materials have higher surface areas than those obtained by the classical evaporation method from nickel nitrate and ammonium niobium oxalate. These consist in NiO nanocrystallites (7-13 nm) associated, at Nb contents >3 at.%., with an amorphous thin layer (1-2 nm) of a niobium-rich mixed oxide with a structure similar to that of NiNb 2O 6. Unlike bulk nickel oxides, the activity of these nanooxides for low-temperature ethane oxidative dehydrogenation (ODH) has been related to their redox properties. In addition to limiting the size of NiO crystallites, the presence of the Nb-rich phase also inhibits NiO reducibility. At Nb content >5 at.%, Nb-NiO composites are thus less active for ethane ODH but more selective, indicating that the Nb-rich phase probably covers part of the unselective, non-stoichiometric, active oxygen species of NiO. This geometric effect is supported by high-resolution transmission electron microscopy observations. The close interaction between NiO and the thin Nb-rich mixed oxide layer, combined with possible restructuration of the nanocomposite under ODH conditions, leads to significant catalyst deactivation at high Nb loadings. Hence, the most efficient ODH catalysts obtained by this method are those containing 3-4 at.% Nb, which combine high activity, selectivity, and stability. The impact of the preparation method on the structural and catalytic properties of Nb-NiO nanocomposites suggests that further improvement in NiO-catalyzed ethane ODH can be expected upon optimization of the catalyst. © 2011 Elsevier Inc. All rights reserved.

  10. Oral nickel exposure may induce Type I hypersensitivity reaction in nickel-sensitized subjects.

    Science.gov (United States)

    Büyüköztürk, Suna; Gelincik, Aslı; Ünal, Derya; Demirtürk, Mustafa; Çelik, Dolay Damla; Erden, Sacide; Çolakoğlu, Bahattin; Erdem Kuruca, Serap

    2015-05-01

    Little is known about the clinical and immunological changes in the nickel allergic patients with systemic symptoms. We aimed to evaluate T helper cell responses of patients with different clinical presentations due to nickel. Patients having various allergic symptoms and positive patch test results to nickel and 20 controls underwent skin prick tests with nickel. IL-10, IL-4, IL-5 and IFN-gamma were measured in the culture supernatants of PBMC stimulated by nickel during lymphocyte proliferation test (LTT). 69 patients (56 female, mean age: 49.2 ± 13.1), 97% having nickel containing dental devices and 20 controls (8 female, mean age 34.9 ± 12.06) were evaluated. Skin prick tests with nickel were positive in 70% of the patients (pType I hypersensitivity in addition to a Type IV immune reaction in patients with chronic systemic symptoms related to nickel. Nickel containing dental alloys and oral nickel intake seem to trigger systemic symptoms in previously nickel sensitized patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Coin exposure may cause allergic nickel dermatitis

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Gawkrodger, David J; White, Ian R

    2012-01-01

    , it is well known by dermatologists specialized in occupational skin diseases, and by their nickel-allergic patients, that hand eczema in cashiers and other professionals who handle coins may be caused or aggravated by nickel release from coins. In this review, we present evidence from past studies showing...

  12. Nickel enhances telomeric silencing in Saccharomyces cerevisiae.

    Science.gov (United States)

    Broday, L; Cai, J; Costa, M

    1999-04-06

    Certain nickel compounds including crystalline nickel sulfide (NiS) and subsulfide (Ni3S2) are potent human and animal carcinogens. In Chinese hamster embryo cells, an X-linked senescence gene was inactivated following nickel-induced DNA methylation. Nickel also induced the inactivation of the gpt reporter gene by chromatin condensation and a DNA methylation process in a transgenic gpt+ Chinese hamster cell line (G12), which is located near a heterochromatic region. To determine if nickel can cause gene silencing independently of DNA methylation, based only on the induction of changes in chromatin structure, we measured its effect on gene silencing in Saccharomyces cerevisiae. Growth of yeast in the presence of nickel chloride repressed a telomeric marker gene (URA3) and resulted in a stable epigenetic switch. This phenomenon was dependent on the number of cell doubling prior to selection and also on the distance of the marker gene from the end of the chromosome. The level of TPE (telomeric position effect) increased linearly with elevations of nickel concentration. Addition of magnesium inhibited this effect, but magnesium did not silence the reporter gene by itself. The level of silencing was also assessed following treatment with other transition metals: cobalt, copper and cadmium. In the sublethal range, cobalt induced similar effects as nickel, while copper and cadmium did not change the basal level of gene expression. Silencing by copper and cadmium were evident only at concentrations of those metals where the viability was very low. Copyright 1999 Elsevier Science B.V.

  13. Gold-nickel-titanium brazing alloy

    Science.gov (United States)

    Mizuhara, Howard

    1990-07-03

    A brazing alloy in accordance with this invention has the following composition, by weight: 91 to 99% gold, 0.5 to 7% nickel; 0.10 to 2% titanium. Alternatively, with palladium present, the composition is as follows, by weight: 83 to 96% gold; 3 to 10% palladium; 0.5 to 5% nickel; 0.10 to 2% titanium.

  14. Biocompatibility of nickel and cobalt dental alloys.

    Science.gov (United States)

    Grimaudo, N J

    2001-01-01

    Allergies related to dentistry generally constitute delayed hypersensitivity reactions to specific dental materials. Although true allergic hypersensitivity to dental materials is rare, certain products have definite allergenic properties. This review presents a comparative evaluation of the biocompatibility of nickel-chromium, nickel-chromium-beryllium, and cobalt-chromium alloys.

  15. Magnetically retrievable nickel hydroxide functionalised AFe2O4 (A = Mn, Ni) spinel nanocatalyst for alcohol oxidation

    Science.gov (United States)

    Bhat, Pooja B.; Bhat, Badekai Ramachandra

    2016-03-01

    Ultrasmall nickel hydroxide functionalised AFe2O4 (A = Mn, Ni) nanocatalyst was synthesized by traditional co-precipitation method and was examined for oxidation of aromatic alcohols to carbonyls using hydrogen peroxide as terminal oxidant. A very high surface area of 104.55 m2 g-1 was achieved for ferromagnetic MnFe2O4 and 100.50 m2 g-1 for superparamagnetic NiFe2O4, respectively. Efficient oxidation was observed due to the synergized effect of nickel hydroxide (bronsted base) on Lewis center (Fe) of the nanocatalyst. Catalyst recycling experiments revealed that the ultrasmall nanocatalyst can be easily recovered by external magnet and applied for nearly complete oxidation of alcohols for at least five successive cycles. Furthermore, the nickel hydroxide functionalised ultrasmall nanocatalyst exhibited higher efficiency for benzyl alcohol oxidation compared to Ni(OH)2, bare MnFe2O4 and NiFe2O4. Higher conversion rate was observed for nickel hydroxide functionalised NiFe2O4 compared to MnFe2O4. Ultrasmall magnetic nickel hydroxide functionalised nanocatalyst showed environmental friendly, greener route for the oxidation of alcohols without significant loss in activity and selectivity within successive runs.

  16. Lead-nickel electrochemical batteries

    CERN Document Server

    Glaize, Christian

    2012-01-01

    The lead-acid accumulator was introduced in the middle of the 19th Century, the diverse variants of nickel accumulators between the beginning and the end of the 20th Century. Although old, these technologies are always very present on numerous markets. Unfortunately they are still not used in optimal conditions, often because of the misunderstanding of the internal electrochemical phenomena.This book will show that batteries are complex systems, made commercially available thanks to considerable amounts of scientific research, empiricism and practical knowledge. However, the design of

  17. Aluminium and nickel in human albumin solutions

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Sandberg, E

    1989-01-01

    Five different brands of commercially available human albumin solutions for infusion were analysed for their aluminium and nickel contents by atomic absorption spectrometry. The aluminium concentrations ranged from 12 micrograms/l to 1109 micrograms/l and the nickel concentrations ranged from 17...... micrograms/l to 77 micrograms/l. Examination of the aluminium and nickel contents of the constituents for the production of one brand showed too low levels to explain the final contamination of the product. By following the aluminium and nickel concentrations of the same brand during the production...... of a batch of albumin solution, filtration was shown to contribute to contamination, although the largest increase in aluminium as well as nickel concentrations appeared during the bulk concentrating process. To avoid health risks to certain patients, regulations should be established requiring aluminium...

  18. Olefin metathesis and catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Kukes, S. G.; Banks, R. L.

    1985-03-12

    Olefins are converted into other olefins having different numbers of carbon atoms by contact with a catalyst comprising an inorganic refractory material containing at least one of tungsten oxide and molybdenum oxide and a promoting amount of at least one treating agent selected from chlorinated silicon compounds, thionyl chloride, and sulfuryl chloride under conditions suitable for the treating agent to promote the activity of tungsten and molybdenum oxides for the disporoportionation reaction.

  19. Exploring Catalyst Behaviours

    OpenAIRE

    Austin, Annie; Cox, Jayne; Barnett, Julia; Thomas, Christine

    2011-01-01

    The ‘Exploring catalyst behaviours’ project continues Defra’s programme of research designed to develop a deeper understanding of pro-environmental behaviour. The research, conducted by Brook Lyndhurst, Dr Julie Barnett of the University of Surrey and Dr Christine Thomas of the Open University, feeds into the body of evidence that is guiding Defra and other stakeholders in developing policy, communications and other interventions to galvanise public action on the environment.The aim of the pr...

  20. Study on Corrosion Migrations within Catalyst-Coated Membranes of Proton Exchange Membrane Electrolyzer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Green, Johney [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mo, Jingke [University of Tennessee; Steen, Stuart [University of Tennessee; Kang, Zhenye [University of Tennessee; Yang, Gaoqiang [University of Tennessee; Taylor, Derrick A. [University of Tennessee; Li, Yifan [University of Tennessee; Toops, Todd J. [Oak Ridge National Laboratory; Brady, Michael P. [Oak Ridge National Laboratory; Retterer, Scott T. [Oak Ridge National Laboratory; Cullen, David A. [Oak Ridge National Laboratory; Zhang, Feng-Yuan [University of Tennessee

    2017-10-09

    The corrosion of low-cost, easily manufactured metallic components inside the electrochemical environment of proton exchange membrane electrolyzer cells (PEMECs) has a significant effect on their performance and durability. In this study, 316 stainless steel (SS) mesh was used as a model liquid/gas diffusion layer material to investigate the migration of corrosion products in the catalyst-coated membrane of a PEMEC. Iron and nickel cation particles were found distributed throughout the anode catalyst layer, proton exchange membrane, and cathode catalyst layer, as revealed by scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. The results indicate the corrosion products of 316 SS are transported from anode to cathode through the nanochannels of the Nafion membrane, resulting in impeded proton transport and overall PEMEC performance loss.

  1. High-Activity Dealloyed Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kongkanand, Anusorn [General Motors LLC, Pontiac, MI (United States)

    2014-09-30

    Reduction of costly Pt usage in proton exchange membrane fuel cell electrodes is one of the major challenges towards development and commercialization of fuel cell vehicles. Although few have met the initial-kinetic activity requirements in a realistic fuel cell device, no catalyst material has ever met the demanding fuel cell durability targets set by DOE. In this project, a team of 4 universities and 2 companies came together to investigate a concept that appeared promising in preliminary non-fuel cell tests then to further develop the catalyst to a mature level ready for vehicle implementation. The team consists of academia with technical leadership in their respective areas, a catalyst supplier, and a fuel cell system integrator.The tightly collaborative project enabled development of a highly active and durable catalyst with performance that significantly exceeds that of previous catalysts and meets the DOE targets for the first time (Figure 1A). The catalyst was then further evaluated in full-active-area stack in a realistic vehicle operating condition (Figure 1B). This is the first public demonstration that one can realize the performance benefit and Pt cost reduction over a conventional pure Pt catalyst in a long-term realistic PEMFC system. Furthermore, systematic analyses of a range of catalysts with different performance after fuel cell testing allowed for correlation between catalyst microstructure and its electrocatalytic activity and durability. This will in turn aid future catalyst development.

  2. Steam reforming catalyst

    Science.gov (United States)

    Kramarz, Kurt W.; Bloom, Ira D.; Kumar, Romesh; Ahmed, Shabbir; Wilkenhoener, Rolf; Krumpelt, Michael

    2001-01-01

    A method of forming a hydrogen rich gas from a source of hydrocarbon fuel. A vapor of the hydrocarbon fuel and steam is brought in contact with a two-part catalyst having a dehydrogenation powder portion and an oxide-ion conducting powder portion at a temperature not less than about 770.degree.C. for a time sufficient to generate the hydrogen rich. The H.sub.2 content of the hydrogen gas is greater than about 70 percent by volume. The dehydrogenation portion of the catalyst includes a group VIII metal, and the oxide-ion conducting portion is selected from a ceramic oxide from the group crystallizing in the fluorite or perovskite structure and mixtures thereof. The oxide-ion conducting portion of the catalyst is a ceramic powder of one or more of ZrO.sub.2, CeO.sub.2, Bi.sub.2 O.sub.3, (BiVO).sub.4, and LaGaO.sub.3.

  3. Ziegler-Natta Catalysts

    Directory of Open Access Journals (Sweden)

    G. Pircheraghi

    2007-12-01

    Full Text Available The effects of temperature, time and the strategy of prepolymerization were studied on the morphology of polypropylene particles. propylene polymerization was carried out in slurry phase using 4th generation of Ziegler-Natta Catalyst, cyclohexylmethyl dimethoxysilane as external electron donor, and triethyl aluminum as co-catalyst. Prepolymerizations were carried out based on two strategies: isothermal and non-isothermal conditions. Particle imaging using SEM, bulk density, and particle size distribution was used to analyse the particle morphology. It was found that the variation of initial condition together with the change in the mechanism of particle fracture has a dominant effect on particle morphology. Each combination between the temperature and reaction time causes to have a special effect on the product particle morphology. It has become clear that in isothermal prepolymerization, spherical particles with identical properties were produced. In low temperature experiments particles with porous surface were observed. At increasing temperature, however, the pores disappeared. Non-isothermal prepolymerization produced different morphological types. In all experiments coreshell structures were observed that seemed to be related to the structure of catalysts.

  4. Highly stable and active Ni-doped ordered mesoporous carbon catalyst on the steam reforming of ethanol application

    Directory of Open Access Journals (Sweden)

    Josh Y.Z. Chiou

    2017-02-01

    Full Text Available A novel one-step direct synthesis of nickel embedded in an ordered mesoporous carbon catalyst (NiOMC is done in a basic medium of nonaqueous solution by a solvent evaporation-induced self-assembly process. The NiOMC sample is characterized by a variety of analytical and spectroscopy techniques, e.g., N2 adsorption/desorption isotherm measurement, X-ray diffraction (XRD, transmission electron microscopy (TEM and temperature-programed reduction (TPR. In this study, the NiOMC catalyst is found to exhibit superior catalytic activity for the steam reforming of ethanol (SRE, showing high hydrogen selectivity and durability. Ethanol can be completely converted at 350 °C over the NiOMC catalyst. Also, the durability of the NiOMC catalyst on the SRE reaction exceeds 100 h at 450 °C, with SH2 approaching 65% and SCO of less than 1%.

  5. Recent progress in nickel carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Sunderman, F.W. Jr.

    1984-01-01

    Positive bacterial mutagenesis tests have been obtained with Ni(II) in Corynybacterium, but not in E. coli, S. typhimurium, or B. subtilis. Transformation assays of several soluble and crystalline Ni compounds have been positive in Syrian hamster embryo cells. Ni(II) binds to DNA, RNA, and nucleoproteins, and becomes localized in nucleoli. Genotoxic effects of Ni include: (a) chromosomal aberrations, including sister-chromatid exchanges, (b) DNA strandbreaks and DNA-protein crosslinks, (c) inhibition of DNA and RNA synthesis, (d) infidelity of DNA transcription, and (e) mutations at the HGPRTase locus in Chinese hamster cells and the TK locus in mouse lymphoma cells. These findings are consistent with somatic mutation as the mechanism for initiation of nickel carcinogenesis. Ni compounds cause reversible transition of double-stranded poly(dG-dC) DNA from the right-handed B-helix to the left-handed Z-helix, suggesting a mechanism whereby nickel might modulate oncogene expression. 99 references, 4 tables.

  6. Regulation of the catalytic behavior of pullulanases chelated onto nickel (II)-modified magnetic nanoparticles.

    Science.gov (United States)

    Wang, Jianfeng; Liu, Zhongmei; Zhou, Zhemin

    2017-06-01

    Chelating of pullulanases onto nickel (II)-modified magnetic nanoparticles results in one-step purification and immobilization of pullulanase, and facilitates the commercial application of pullulanase in industrial scale. To improve the catalytic behavior, especially the operational stability, of the nanocatalyst in consecutive batch reactions, we prepared various iminodiacetic acid-modified magnetic nanoparticles differed in surface polarity and spacer length, on which the His6-tagged pullulanases were chelated via nickel ions, and then studied the correlation between the MNPs surface property and the corresponding catalyst behavior. When pullulanases were chelated onto the surface-modified MNPs, the thermostability of all pullulanase derivatives were lower than that of free counterpart, being not relevant to the protein orientation guided by the locality of the His6-tag, but related to the MNPs basal surface polarity and the grafted spacer length. After chelating of pullulanases onto MNPs, there were changes observed in the pH-activity profile and the apparent Michaelis constant toward pullulan. The changing tendencies were mainly dependent on the His6-tagged pullulanase orientation, and the changing extents were tuned by the spacer length. The reusability of pullulanase immobilized by N-terminal His6-tag was higher than that of pullulanase immobilized by C-terminal His6-tag. Moreover, the reusability of the immobilized pullulanase tested increased till grafting polyether amine-400 as spacer-arm, therefore the N-terminal His6-tagged pullulanase chelating MNPs grafted polyether amine-400 gave the best reusability, which retained 60% of initial activity after 18 consecutive cycles with a total reaction time of 9h. Additionally, the correlation analysis of the catalyst behaviors indicated that the reusability was independent from other catalytic properties such as thermostability and substrate affinity. All the results revealed that the catalyst behavior can be

  7. Non-PGM cell catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Colon-Mercado, H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Elvington, M. [Savannah River Consulting, Aiken, SC (United States); Ganesan, P. [Savannah River Consulting, Aiken, SC (United States)

    2017-09-27

    A unique approach has been developed to probe the non-PGM catalyst active site for the Oxygen Reduction Reaction (ORR) for PEMFCs. Iron based functionalities have been engineered into a variety of catalysts to evaluate their impact on activity for the ORR. A series of high surface area catalysts were synthesized and the impact of the chemical structure on the electrochemical and electrocatalytic properties was investigated. Elemental and surface analyses of the prepared catalysts reveal the incorporation of iron in a targeted and controlled manner. A high surface area framework catalyst was prepared that shows exceptional activity, comparable to state-of-the-art materials. The results of this research project provided critical seed data for the newly awarded ElectroCat project, which focuses on rationally designed framework catalysts for the oxygen reduction reaction.

  8. Study of Novel EUV Absorber : Nickel and Nickel Oxide

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Dong Gon; Kim, Jung Hwan; Kim, Jung Sik; Hong, Seongchul; Ahn, Jinho [Hanyang University, Seoul (Korea, Republic of)

    2017-03-15

    The shadowing effect is one of the most urgent issues yet to be solved in high-volume manufacturing using extreme ultraviolet lithography (EUVL). Many studies have been conducted to mitigate the unexpected results caused by shadowing effects. The simplest way to mitigate the shadowing effect is to reduce the thickness of the absorber. Since nickel has high extinction coefficients in the EUV wavelengths, it is one of more promising absorber material candidates. A Ni based absorber exhibited imaging performance comparable to a Tantalum nitride absorber. However, the Ni-based absorber showed a dramatic reduction in horizontal-vertical critical dimension (H-V CD) bias. Therefore, limitations in fabricating a EUV mask can be mitigated by using the Ni based absorber.

  9. Development of GREET Catalyst Module

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhichao [Argonne National Lab. (ANL), Argonne, IL (United States); Benavides, Pahola T. [Argonne National Lab. (ANL), Argonne, IL (United States); Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States); Cronauer, Donald C. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    In this report, we develop energy and material flows for the production of five different catalysts (tar reforming, alcohol synthesis, Zeolite Socony Mobil-5 [ZSM-5], Mo/Co/ γ-Al2O3, and Pt/ γ-Al2O3) and two chemicals (olivine, dimethyl ether of polyethylene glycol [DEPG]). These compounds and catalysts are now included in the Greenhouse Gases, Regulated Emissions and Energy Use in Transportation (GREET™) catalyst module.

  10. Catalyst systems and uses thereof

    Science.gov (United States)

    Ozkan, Umit S [Worthington, OH; Holmgreen, Erik M [Columbus, OH; Yung, Matthew M [Columbus, OH

    2012-07-24

    A method of carbon monoxide (CO) removal comprises providing an oxidation catalyst comprising cobalt supported on an inorganic oxide. The method further comprises feeding a gaseous stream comprising CO, and oxygen (O.sub.2) to the catalyst system, and removing CO from the gaseous stream by oxidizing the CO to carbon dioxide (CO.sub.2) in the presence of the oxidation catalyst at a temperature between about 20 to about 200.degree. C.

  11. Oxygen-reducing catalyst layer

    Science.gov (United States)

    O'Brien, Dennis P [Maplewood, MN; Schmoeckel, Alison K [Stillwater, MN; Vernstrom, George D [Cottage Grove, MN; Atanasoski, Radoslav [Edina, MN; Wood, Thomas E [Stillwater, MN; Yang, Ruizhi [Halifax, CA; Easton, E Bradley [Halifax, CA; Dahn, Jeffrey R [Hubley, CA; O'Neill, David G [Lake Elmo, MN

    2011-03-22

    An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

  12. Treatment of spent catalyst from the nitrogenous fertilizer industry--a review of the available methods of regeneration, recovery and disposal.

    Science.gov (United States)

    Singh, Bina

    2009-08-15

    Disposal of spent catalyst is a problem as it falls under the category of hazardous industrial waste. The recovery of metals from these catalysts is an important economic aspect as most of these catalysts are supported, usually on alumina/silica with varying percent of metal; metal concentration could vary from 2.5 to 20%. Metals like Ni, Mo, Co, Rh, Pt, Pd, etc., are widely used as a catalyst in chemical and petrochemical industries and fertilizer industries. They are generally supported on porous materials like alumina and silica through precipitation or impregnation processes. Many workers have adapted pyrometallurgy and Hydrometallurgy process for recovery of precious metals. Many workers have studied the recovery of nickel from a spent catalyst in an ammonia plant by leaching it in sulphuric acid solution (Hydrometallurgy). Ninety-nine percent of the nickel was recovered as nickel sulphate when the catalyst, having a particle size of 0.09 mm was dissolved in an 80% sulphuric acid solution for 50 min in at 70 degrees C. Many researcher have studied the extraction of metals from spent catalyst by roasting-extraction method (Pyrometallurgy). Chelating agents are the most effective extractants, which can be introduced in the soil washing fluid to enhance heavy metal extraction from contaminated soils. The advantages of chelating agents in soil cleanup include high efficiency of metal extraction, high thermodynamic stabilities of the metal complexes formed, good solubilities of the metal complexes, and low adsorption of the chelating agents on soils, But very few workers have attempted chelating agent to extract metals from spent catalyst.

  13. Fine particle clay catalysts for coal liquefaction. Quarterly technical progress report, May 9, 1992--August 8, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Olson, E.S.

    1995-10-01

    An investigation of new methods for the production of mixed pillared clay catalysts and clay-supported catalysts and determination of their catalytic activities were continued in this quarter. To demonstrate the reproducibility of the preparative method for high activity iron/alumina-pillared montmorillonite catalysts, a new batch of the catalyst was prepared and tested for hydrocracking activity with bibenzyl. This preparation gave conversion and product distribution similar to that reported previously. The mixed iron/alumina-pillared clay was also prepared using a pillaring solution that was aged for longer period of time. To determine the importance of the type of pillaring support in hydrocracking activity, iron/zirconia-pillared montmorillonite was prepared using the same technique as that for iron/alumina-pillared montmorillonite. The reaction of bibenzyl with the sulfided iron/zirconia-pillared catalyst gave a lower hydrocracking conversion than the iron/alumina-pillared catalyst. Addition of a second catalytic metal to the clay support was attempted to determine if a synergistic effect could improve liquefaction. Ferric nitrate and stannous chloride were added to the clay, but the resulting catalyst was relatively poor for hydrocracking and hydrogenation compared with ferric nitrate supported on the clay. New disposable iron catalysts with high acidity and surface area are desired for coal liquefaction. Synthetic iron aluminosilicates were prepared by methods similar to those used for the nickel-substituted synthetic mica montmorillonite (NiSMM) catalysts, which are very effective for hydrogenation and reforming of hydrocarbons. The iron aluminosilicate catalysts were tested for hydrocracking and hydrogenation of bibenzyl, naphthalene and pyrene. Pyrene hydrogenation was effectively catalyzed by the sulfided synthetic iron catalyst.

  14. Efficient hydrogen evolution by ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam

    Science.gov (United States)

    Zhou, Haiqing; Yu, Fang; Huang, Yufeng; Sun, Jingying; Zhu, Zhuan; Nielsen, Robert J.; He, Ran; Bao, Jiming; Goddard, William A., III; Chen, Shuo; Ren, Zhifeng

    2016-09-01

    With the massive consumption of fossil fuels and its detrimental impact on the environment, methods of generating clean power are urgent. Hydrogen is an ideal carrier for renewable energy; however, hydrogen generation is inefficient because of the lack of robust catalysts that are substantially cheaper than platinum. Therefore, robust and durable earth-abundant and cost-effective catalysts are desirable for hydrogen generation from water splitting via hydrogen evolution reaction. Here we report an active and durable earth-abundant transition metal dichalcogenide-based hybrid catalyst that exhibits high hydrogen evolution activity approaching the state-of-the-art platinum catalysts, and superior to those of most transition metal dichalcogenides (molybdenum sulfide, cobalt diselenide and so on). Our material is fabricated by growing ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam. This advance provides a different pathway to design cheap, efficient and sizable hydrogen-evolving electrode by simultaneously tuning the number of catalytic edge sites, porosity, heteroatom doping and electrical conductivity.

  15. Lanthanum and cerium co-modified Ni/SiO2 catalyst for CO methanation from syngas

    Science.gov (United States)

    Gong, Dandan; Li, Shuangshuang; Guo, Shaoxia; Tang, Honggui; Wang, Hong; Liu, Yuan

    2018-03-01

    Sintering of active metal nanoparticles (NPs) and carbon deposition is critical problems for many metal catalysts, such as nickel based catalysts for generating methane from syngas. To improve the resistance to the sintering and carbon deposition, a new scheme was proposed in this work. Lanthanum and cerium co-modified Ni/SiO2 catalysts were synthesized by using perovskite type oxide of La1-xCexNiO3 loaded on SiO2 as the precursor. In a nanocrystallite of La1-xCexNiO3, ions of nickel, lanthanum and cerium are evenly mixed at atomic level and confined in the nanocrystallite, therefore, Ni NPs and the two promoters of La2O3 and CeO2 should be in close contact and highly dispersed on SiO2 after reduction. The catalysts were characterized by using XRD, TEM, BET, H2-TPD, XPS, TG and Raman techniques. Compared with the mono-promoted catalysts, the bi-promoted La0.75Ce0.25NiO3/SiO2 showed much better resistance to carbon deposition, higher resistance to sintering and higher activity for CO methanation, which are attributed to co-eliminating effect of the two promoters for the deposited carbon, confinement of the interacted two promoters for Ni NPs and the higher dispersion of Ni NPs derived from the smaller size of La0.75Ce0.25NiO3.

  16. Mixed Alcohol Synthesis Catalyst Screening

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Mark A.; White, James F.; Stevens, Don J.

    2007-09-03

    National Renewable Energy Laboratory (NREL) and Pacific Northwest National Laboratory (PNNL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially available or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. From the standpoint of producing C2+ alcohols as the major product, it appears that the rhodium catalyst is the best choice in terms of both selectivity and space-time yield (STY). However, unless the rhodium catalyst can be improved to provide minimally acceptable STYs for commercial operation, mixed alcohol synthesis will involve significant production of other liquid coproducts. The modified Fischer-Tropsch catalyst shows the most promise for providing both an acceptable selectivity to C2+ alcohols and total liquid STY. However, further optimization of the Fischer-Tropsch catalysts to improve selectivity to higher alcohols is highly desired. Selection of a preferred catalyst will likely entail a decision on the preferred coproduct slate. No other catalysts tested appear amenable to the significant improvements needed for acceptable STYs.

  17. Nickel on the Swedish market: follow-up 10 years after entry into force of the EU Nickel Directive.

    NARCIS (Netherlands)

    Biesterbos, J.W.H.; Yazar, K.; Liden, C.

    2010-01-01

    BACKGROUND: The EU Nickel Directive, aimed at primary and secondary prevention of nickel allergy by limitation of nickel release from certain items, came fully into force in July 2001. OBJECTIVES: To assess the prevalence on the market of items with nickel release and to compare the outcome with

  18. Pulsed Electrodeposited Nickel – Cerium for Hydrogen Production Studies

    OpenAIRE

    Sivaranjani, T; Revathy, T A; Dhanapal, K; Narayanan, V; A. Stephen

    2017-01-01

    International audience; The approach of alloying different elements results in new alloy phase with exclusive properties that could be a potential candidate in various applications. In the present work an attempt has been made to electrodeposit Nickel-Cerium (NiCe) alloy. Nickel is an intriguing metal with much availability in earth's crust. The catalytic power of Nickel based alloys towards hydrogen evolution reaction has been already reported for Nickel-Metal alloys, NiO/Ni and Nickel-Rare ...

  19. Nickel-free austenitic stainless steels for medical applications

    OpenAIRE

    Yang, Ke; Ren, Yibin

    2010-01-01

    The adverse effects of nickel ions being released into the human body have prompted the development of high-nitrogen nickel-free austenitic stainless steels for medical applications. Nitrogen not only replaces nickel for austenitic structure stability but also much improves steel properties. Here we review the harmful effects associated with nickel in medical stainless steels, the advantages of nitrogen in stainless steels, and emphatically, the development of high-nitrogen nickel-free stainl...

  20. REACTOR FILLED WITH CATALYST MATERIAL, AND CATALYST THEREFOR

    NARCIS (Netherlands)

    Sie, S.T.

    1995-01-01

    Abstract of WO 9521691 (A1) Described is a reactor (1) at least partially filled with catalyst granules (11), which is intended for catalytically reacting at least one gas and at least one liquid with each other. According to the invention the catalyst granules (11) are collected in agglomerates

  1. Novel Reforming Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Pfefferle, Lisa D; Haller, Gary L

    2012-10-16

    Aqueous phase reforming is useful for processing oxygenated hydrocarbons to hydrogen and other more useful products. Current processing is hampered by the fact that oxide based catalysts are not stable under high temperature hydrothermal conditions. Silica in the form of structured MCM-41 is thermally a more stable support for Co and Ni than conventional high surface area amorphous silica but hydrothermal stability is not demonstrated. Carbon nanotube supports, in contrast, are highly stable under hydrothermal reaction conditions. In this project we show that carbon nanotubes are stable high activity/selectivity supports for the conversion of ethylene glycol to hydrogen.

  2. A Catalyst for Change

    DEFF Research Database (Denmark)

    Lønsmann, Dorte

    2017-01-01

    into in a process that hinges on new members functioning as tools for management to bring about the desired change. The article shows that while the newcomer is used as a catalyst for increased use of English and for the creation of a 'global mindset,' she is at the same time socialized into the existing Danish...... for changing language practices toward more English, with the ultimate aim of creating a 'global mindset' in the organization. Language socialization in a transient multilingual setting is shown to focus on and assign positive value to new linguistic norms that experienced members are socialized...

  3. Absorption and retention of nickel from drinking water in relation to food intake and nickel sensitivity.

    Science.gov (United States)

    Nielsen, G D; Søderberg, U; Jørgensen, P J; Templeton, D M; Rasmussen, S N; Andersen, K E; Grandjean, P

    1999-01-01

    Two studies were performed to examine the influence of fasting and food intake on the absorption and retention of nickel added to drinking water and to determine if nickel sensitization played any role in this regard. First, eight nonallergic male volunteers fasted overnight before being given nickel in drinking water (12 micrograms Ni/kg) and, at different time intervals, standardized 1400-kJ portions of scrambled eggs. When nickel was ingested in water 30 min or 1 h prior to the meal, peak nickel concentrations in serum occurred 1 h after the water intake, and the peak was 13-fold higher than the one seen 1 h after simultaneous intake of nickel-containing water and scrambled eggs. In the latter case, a smaller, delayed peak occurred 3 h after the meal. Median urinary nickel excretion half-times varied between 19.9 and 26.7 h. Within 3 days, the amount of nickel excreted corresponded to 2.5% of the nickel ingested when it was mixed into the scrambled eggs. Increasing amounts were excreted as the interval between the water and the meal increased, with 25.8% of the administered dose being excreted when the eggs were served 4 h prior to the nickel-containing drinking water. In the second experiment, a stable nickel isotope, 61Ni, was given in drinking water to 20 nickel-sensitized women and 20 age-matched controls, both groups having vesicular hand eczema of the pompholyx type. Nine of 20 nickel allergic eczema patients experienced aggravation of hand eczema after nickel administration, and three also developed a maculopapular exanthema. No exacerbation was seen in the control group. The course of nickel absorption and excretion in the allergic groups did not differ and was similar to the pattern seen in the first study, although the absorption in the women was less. A sex-related difference in gastric emptying rates may play a role. Thus, food intake and gastric emptying are of substantial significance for the bioavailability of nickel from aqueous solutions

  4. Análise por componentes principais de espectros nexafs na especiação do molibdênio em catalisadores de hidrotratamento Principal component analysis of nexafs spectra for molybdenum speciation in hydrotreating catalysts

    Directory of Open Access Journals (Sweden)

    Arnaldo da C. Faro Jr

    2010-01-01

    Full Text Available Bulk and supported molybdenum based catalysts, modified by nickel, phosphorous or tungsten were studied by NEXAFS spectroscopy at the Mo L III and L II edges. The techniques of principal component analysis (PCA together with a linear combination analysis (LCA allowed the detection and quantification of molybdenum atoms in two different coordination states in the oxide form of the catalysts, namely tetrahedral and octahedral coordination.

  5. Vieillissement des catalyseurs de craquage sous l'effet des conditions hydrothermiques et du dépôt de métaux Aging of Cracking Catalysts under the Effect of Hydrothermal Conditions and Metal Deposits

    Directory of Open Access Journals (Sweden)

    Marcilly C.

    2006-11-01

    Full Text Available This article is a bibliographic update on the aging of FCC catalysts under the effect of the severe hydrothermal conditions encountered in regenerators in industrial plants as well as metallic poisons, mainly nickel and vanadium, contained in feedstocks. After examining the changes or degradations undergone by catalysts, particularly by the zeolite Y they contain, and their consequences on catalytic performances, various solutions described in the literature are given, some of which are used industrially.

  6. In-situ characterization of heterogeneous catalysts

    CERN Document Server

    Rodriguez, Jose A; Chupas, Peter J

    2013-01-01

    Helps researchers develop new catalysts for sustainable fuel and chemical production Reviewing the latest developments in the field, this book explores the in-situ characterization of heterogeneous catalysts, enabling readers to take full advantage of the sophisticated techniques used to study heterogeneous catalysts and reaction mechanisms. In using these techniques, readers can learn to improve the selectivity and the performance of catalysts and how to prepare catalysts as efficiently as possible, with minimum waste. In-situ Characterization of Heterogeneous Catalysts feat

  7. Carbon-supported platinum alloy catalysts for phenol hydrogenation for making industrial chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, S.T.; Song, C.

    1999-07-01

    Phenol is available in large quantities in liquids derived from coal and biomass. Phenol hydrogenation is an industrially important reaction to produce cyclohexanone and cyclohexanol. Cyclohexane, cyclohexene and benzene are obtained as minor products in this reaction. Cyclohexanone is an important intermediate in the production of caprolactam for nylon 6 and cyclohexanol for adipic acid production. In USA, cyclohexanol and cyclohexanone are produced by benzene hydrogenation to cyclohexane over nickel or noble metal catalysts, followed by oxidation of cyclohexane to produce a mixture of cyclohexanol and cyclohexanone. Then cyclohexanol is dehydrogenated in the presence of Cu-Zn catalyst to cyclohexanone. Usually phenol hydrogenation is also carried out by using Ni catalyst in liquid phase. However, a direct single-step vapor phase hydrogenation of phenol to give cyclohexanone selectively is more advantageous in terms of energy savings and process economics, since processing is simplified and the endothermic step of cyclohexanol dehydrogenation can be avoided, as demonstrated by Montedipe and Johnson Matthey using promoted Pd/Al{sub 2}O{sub 3} catalyst. While it is not the purpose of this paper to dwell on the relative merits of these routes, it is necessary to mention that while using monometallic catalysts, generally the problem of catalyst deactivation of sintering as well as coking is frequently encountered. Addition and alloying of noble metal (e.g. Pt) with a second metal can result in a catalyst with better selectivity and activity in the reaction which is more resistant to deactivation. This paper presents the results on the single-step vapor phase hydrogenation of phenol over carbon-supported Pt-M (M=Cr, V, Zr) alloy catalysts to yield mainly cyclohexanone or cyclohexanol.

  8. An Effective Pd–Ni2P/C Anode Catalyst for Direct Formic Acid Fuel Cells

    OpenAIRE

    Chang, Jinfa; Feng, Ligang; Liu, Changpeng; Xing, Wei; Hu, Xile

    2014-01-01

    The direct formic acid fuel cell is an emerging energy conversion device for which palladium is considered as the state-of-the-art anode catalyst. In this communication, we show that the activity and stability of palladium for formic acid oxidation can be significantly enhanced using nickel phosphide (Ni2P) nanoparticles as a cocatalyst. X-ray photoelectron spectroscopy (XPS) reveals a strong electronic interaction between Ni2P and Pd. A direct formic acid fuel cell incorporating the best Pd-...

  9. Organic chemistry: Nickel steps towards selectivity

    Science.gov (United States)

    Gaunt, Matthew; Williamson, Patrick

    2017-05-01

    Hydrocarbons called alkenes are isolated from petroleum as mixtures of isomers, often making it hard to use them as reagents for synthesis. A reaction involving a migrating nickel atom offers a possible solution. See Letter p.84

  10. Microwave-Assisted Synthesis of Nickel Oxide Nanoparticles Using Coriandrum sativum Leaf Extract and Their Structural-Magnetic Catalytic Properties

    Directory of Open Access Journals (Sweden)

    Ramakrishnan Azhagu Raj

    2017-04-01

    Full Text Available In this paper, using Coriandrum sativum L., a leaf-extracted, assisted microwave method (MM was used to synthesize nickel oxide formation. We synthesized nickel oxide nanoparticles (NiO with a crystal size in the range of 15–16 nm by a Coriandrum sativum leaf-assisted microwave method (LAMM. The synthesized materials show that an X-ray diffraction (XRD study confirmed the formation of a single phase structure exhibiting a crystallite size in the range of 15–16 nm using Scherrer’s method. The nickel oxide prepared by the MM had a surface area of 60.35 m2/g, pore volume of 0.9427 cm3/g and an average pore diameter of 13.27 Å. Surface morphology was analyzed by the scanning electron microscope (SEM, X-ray photoelectron spectroscope, Brunauer-Emmett-Teller (BET analysis, and the vibrating sample magnetometer (VSM. Catalytic activity (CA tended toward the oxidation of styrene to benzaldehyde. The inexpensive catalyst tested is likely effective as a catalyst due to synergistic interactions between metal oxides with high dispersion. In comparison with other findings, LAMM is easy and eco-friendly. The current study obtained nanocrystalline NiO that was suitable for potential applications in catalysis. The synthesized NiO could potentially be used in therapeutic field due to their competent antibacterial activity.

  11. Shock activation of catalysts

    Science.gov (United States)

    Graham, R. A.; Morosin, B.; Richards, P. M.; Stohl, F. V.; Granoff, B.

    1981-02-01

    Scientists in the Soviet Union have demonstrated that high pressure shock-wave loading can cause significant improvement in the performance of catalysts. This increased catalytic activity is apparently the result of the shock-induced defects, especially vacancies, which act to facilitate atomic migration. We have carried out shock activation experiments on a coal-derived pyrite which has been previously used as a catalyst in coal liquefaction studies. The pyrite powder was packed to a density of about 2.0 Mg/m3 in a copper capsule and explosively loaded to a pressure of about 15 GPa in the copper. The starting and shock-activated samples were analyzed by x-ray diffraction and magnetization measurements. The diffraction patterns of the shock-activated samples were dominated by broadened pyrite lines indicative of a significant increase in crystal defects. The diffraction patterns also showed the presence of pyrrhotite (Fe1-xS) in quantities of a few percent. An iron carbide found in the shocked material was apparently formed from carbon originating from either the calcite or organic impurities in the starting material. Magnetic properties of the sample were found to be substantially changed by the shock loading. The study has demonstrated that shock loading can significantly alter the crystalline order of pyrite and produce measurable quantities of pyrrhotite. The effects of shock-activated pyrite on the liquefaction of coal are being assessed by means by tubing reactor experiments.

  12. Nickel metal hydride LEO cycle testing

    Science.gov (United States)

    Lowery, Eric

    1995-01-01

    The George C. Marshall Space Flight Center is working to characterize aerospace AB5 Nickel Metal Hydride (NiMH) cells. The cells are being evaluated in terms of storage, low earth orbit (LEO) cycling, and response to parametric testing (high rate charge and discharge, charge retention, pulse current ability, etc.). Cells manufactured by Eagle Picher are the subjects of the evaluation. There is speculation that NiMH cells may become direct replacements for current Nickel Cadmium cells in the near future.

  13. Toxicity of nickel ores to marine organisms.

    Science.gov (United States)

    Florence, T M; Stauber, J L; Ahsanullah, M

    1994-06-06

    Queensland Nickel proposes to import New Caledonian (Ballande) and Indonesian (Gebe) nickel ores, one option being ship-to-barge transfer in Halifax Bay, North Queensland. Because small amounts of ore may be split during the unloading and transfer operations, it was important to investigate the potential impact of the spilt ore on the ecological health of the Bay. Long-term leaching of the ores with seawater showed that only nickel and chromium (VI) were released from the ores in sufficient concentrations to cause toxicity to a range of marine organisms. The soluble fractions of nickel and chromium (VI) were released from the ores within a few days. Nickel, chromium (VI) and the ore leachates showed similar toxicity to the juvenile banana prawn Penaeus merguiensis, the amphipod Allorchestes compressa and both temperature (22 degrees C) and tropical (27 degrees C) strains of the unicellular marine alga Nitzschia closterium. In a series of 30-day sub-chronic microcosm experiments, juvenile leader prawns Penaeus monodon, polychaete worms Galeolaria caespitosa and the tropical gastropod Nerita chamaeleon were all very resistant to the nickel ores, with mortality unaffected by 700 g ore per 50 l seawater. The growth rate of the leader prawns was, however, lower than that of the controls. From these data, a conservative maximum safe concentration of the nickel ores in seawater is 0.1 g l-1. The nickel ore was not highly toxic and if spilt in the quantities predicted, would not have a significant impact on the ecological health of the Bay.

  14. Magnetic properties of mosaic nanocomposites composed of nickel and cobalt nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Castillo-Sepúlveda, S.; Corona, R.M. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Altbir, D. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), 9170124 Santiago (Chile); Escrig, J., E-mail: juan.escrig@usach.cl [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), 9170124 Santiago (Chile)

    2016-10-15

    Mosaic nanocomposites composed of nickel and cobalt nanowires arranged in different configurations were investigated using Monte Carlo simulations and a simple model that considers single-domain structures including length corrections due to the shape anisotropy. Our results showed that for an ordered array both the coercivity and the remanence decrease linearly as a function of the concentration of nickel nanowires. Besides, we obtained that the magnetic properties of an array of a certain hard magnetic material (cobalt) will not change, unless we have more than 50% of nanowires of other soft magnetic material (nickel) in the array. In principle the second material could be other soft magnetic material, but could also be a nonmagnetic material or could even be a situation in which some of the pore arrays were not filled by electrodeposition. Therefore, our results allow us to predict the behavior of magnetic mosaic nanocomposites that are promising candidates for functional electrodes, sensors, and model catalysts. - Highlights: • Mosaic nanocomposites composed of magnetic nanowires were investigated. • Magnetic properties can be adjusted by varying the concentration of nanowires. • Our results allow us to predict the behavior of magnetic mosaic nanocomposites.

  15. Nickel-Doped Ceria Nanoparticles: The Effect of Annealing on Room Temperature Ferromagnetism

    Directory of Open Access Journals (Sweden)

    Joseph C. Bear

    2015-08-01

    Full Text Available Nickel-doped cerium dioxide nanoparticles exhibit room temperature ferromagnetism due to high oxygen mobility within the doped CeO2 lattice. CeO2 is an excellent doping matrix as it can lose oxygen whilst retaining its structure. This leads to increased oxygen mobility within the fluorite CeO2 lattice, leading to the formation of Ce3+ and Ce4+ species and hence doped ceria shows a high propensity for numerous catalytic processes. Magnetic ceria are important in several applications from magnetic data storage devices to magnetically recoverable catalysts. We investigate the effect doping nickel into a CeO2 lattice has on the room temperature ferromagnetism in monodisperse cerium dioxide nanoparticles synthesised by the thermal decomposition of cerium(III and nickel(II oleate metal organic precursors before and after annealing. The composition of nanoparticles pre- and post-anneal were analysed using: TEM (transmission electron microscopy, XPS (X-ray photoelectron spectroscopy, EDS (energy-dispersive X-ray spectroscopy and XRD (X-ray diffraction. Optical and magnetic properties were also studied using UV/Visible spectroscopy and SQUID (superconducting interference device magnetometry respectively.

  16. Nickel acts as an adjuvant during cobalt sensitization

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menne; Nielsen, Morten Milek; Vennegaard, Marie T.

    2015-01-01

    Metal allergy is the most frequent form of contact allergy with nickel and cobalt being the main culprits. Typically, exposure comes from metal-alloys where nickel and cobalt co-exist. Importantly, very little is known about how co-exposure to nickel and cobalt affects the immune system. We...... investigated these effects by using a recently developed mouse model. Mice were epicutaneously sensitized with i) nickel alone, ii) nickel in the presence of cobalt, iii) cobalt alone, or iv) cobalt in the presence of nickel, and then followed by challenge with either nickel or cobalt alone. We found...... that sensitization with nickel alone induced more local inflammation than cobalt alone as measured by increased ear-swelling. Furthermore, the presence of nickel during sensitization to cobalt led to a stronger challenge response to cobalt as seen by increased ear-swelling and increased B and T cell responses...

  17. Selective Reductive Removal of Ester and Amide Groups from Arenes and Heteroarenes through Nickel-Catalyzed C−O and C−N Bond Activation

    KAUST Repository

    Yue, Huifeng

    2017-03-21

    An inexpensive nickel(II) catalyst and a hydrosilane were used for the efficient reductive defunctionalization of aryl and heteroaryl esters through a decarbonylative pathway. This versatile method could be used for the removal of ester and amide functional groups from various organic molecules. Moreover, a scale-up experiment and a synthetic application based on the use of a removable carboxylic acid directing group highlight the usefulness of this reaction.

  18. Nickel biopathways in tropical nickel hyperaccumulating trees from Sabah (Malaysia)

    Science.gov (United States)

    van der Ent, Antony; Callahan, Damien L.; Noller, Barry N.; Mesjasz-Przybylowicz, Jolanta; Przybylowicz, Wojciech J.; Barnabas, Alban; Harris, Hugh H.

    2017-02-01

    The extraordinary level of accumulation of nickel (Ni) in hyperaccumulator plants is a consequence of specific metal sequestering and transport mechanisms, and knowledge of these processes is critical for advancing an understanding of transition element metabolic regulation in these plants. The Ni biopathways were elucidated in three plant species, Phyllanthus balgooyi, Phyllanthus securinegioides (Phyllanthaceae) and Rinorea bengalensis (Violaceae), that occur in Sabah (Malaysia) on the Island of Borneo. This study showed that Ni is mainly concentrated in the phloem in roots and stems (up to 16.9% Ni in phloem sap in Phyllanthus balgooyi) in all three species. However, the species differ in their leaves - in P. balgooyi the highest Ni concentration is in the phloem, but in P. securinegioides and R. bengalensis in the epidermis and in the spongy mesophyll (R. bengalensis). The chemical speciation of Ni2+ does not substantially differ between the species nor between the plant tissues and transport fluids, and is unambiguously associated with citrate. This study combines ion microbeam (PIXE and RBS) and metabolomics techniques (GC-MS, LC-MS) with synchrotron methods (XAS) to overcome the drawbacks of the individual techniques to quantitatively determine Ni distribution and Ni2+ chemical speciation in hyperaccumulator plants.

  19. Equilibrium nickel isotope fractionation in nickel sulfide minerals

    Science.gov (United States)

    Liu, Shanqi; Li, Yongbing; Ju, Yiwen; Liu, Jie; Liu, Jianming; Shi, Yaolin

    2018-02-01

    Nickel is an important element on Earth, and a major element in the Earth's core, and plays important roles in many geological and biological systems. As an important sink of Ni, Ni sulfides are closely concerned with Ni migration in magma systems and the genesis and evolution of magmatic sulfide deposits. Ni isotopes of Ni sulfides may be a powerful geochemical tracer in magmatic processes and evolution of magmatic sulfide deposits. However Ni isotope fractionation factors of sulfides remain poorly known, which makes the applications of Ni isotopes to geological problems associated with sulfides difficult. In this study, the first-principles methods are used to compute Ni isotope fractionation parameters of polydymite (Ni3S4), heazlewoodite (Ni3S2), millerite (NiS), godlevskite (Ni9S8) and vaesite (NiS2). The reduced partition function ratios of 60Ni/58Ni (103 lnβ60-58) for these minerals decrease in the order of polydymite > heazlewoodite > millerite > godlevskite > vaesite. Ni isotope fractionations in these Ni sulfides show an approximately linear dependence on the average Nisbnd S bond lengths, and have a significant negative correlation with the average Nisbnd Ni bond lengths. Furthermore, a change in Fe/Ni ratio can also lead to Ni isotope fractionation, and with substitution Fe for Ni, the reduced partition function ratios of 60Ni/58Ni decrease.

  20. Application of Cement Clinker as Ni-Catalyst Support for Glycerol Dry Reforming

    Directory of Open Access Journals (Sweden)

    Hua Chyn Lee

    2013-12-01

    Full Text Available The increase in biodiesel production inevitably yield plethora of glycerol. Therefore, glycerol has been touted as the most promising source for bio-syngas (mixture of H2 and CO production. Significantly, coking on nickel-based catalysts has been identified as a major deactivation factor in reforming technology. Indeed, coke-resistant catalyst development is essential to enhance syngas production. The current work develops cement clinker (comprised of 62.0% calcium oxide-supported nickel catalyst (with metal loadings of 5, 10, 15 and 20 wt% for glycerol dry reforming (CO2. Physicochemical characterization of the catalysts was performed using XRD, XRF, BET, TGA and FESEM-EDS techniques. Subsequently, reaction studies were conducted in a 7-mm ID fixed-bed stainless steel reactor at 1023 K with various CO2 partial pressures at constant weight-hourly space velocity (WHSV of 7.2×104 ml gcat-1 h-1. Gas compositions were determined using Agilent 3000 micro-gas chromatography (GC and Lancom III gas analyzer. Results obtained showed an increment of BET surface area up to 32-fold with Ni loading which was corroborated by FESEM images. Syngas (H2 and CO ratios of less than 2 were being produced at 1023 K. A closer scrutiny to the transient profile revealed that the presence of CO2 higher or lower than CGR 1:1 promotes the Boudouard reaction. © 2013 BCREC UNDIP. All rights reservedReceived: 30th May 2013; Revised: 27th August 2013; Accepted: 11st September 2013[How to Cite: Lee, H.C., Siew, W.K., Cheng, C.K. (2013. Preparation Application of Cement Clinker as Ni-Catalyst Support for Glycerol Dry Reforming. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (2: 137-144. (doi:10.9767/bcrec.8.2.5023.137-144][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.2.5023.137-144

  1. An environmentally friendly process for the recovery of valuable metals from spent refinery catalysts.

    Science.gov (United States)

    Rocchetti, Laura; Fonti, Viviana; Vegliò, Francesco; Beolchini, Francesca

    2013-06-01

    The present study dealt with the whole valorization process of exhaust refinery catalysts, including metal extraction by ferric iron leaching and metal recovery by precipitation with sodium hydroxide. In the leaching operation the effects on metal recovery of the concentration and kind of acid, the concentration of catalyst and iron (III) were determined. The best operating conditions were 0.05 mol L(-1) sulfuric acid, 40 g L(-1) iron (III), 10% catalyst concentration; almost complete extraction of nickel and vanadium, and 50%extraction efficiency of aluminium and less than 20% for molybdenum. Sequential precipitation on the leach liquor showed that it was not possible to separate metals through such an approach and a recovery operation by means of a single-stage precipitation at pH 6.5 would simplify the procedures and give a product with an average content of iron (68%), aluminium (13%), vanadium (11%), nickel (6%) and molybdenum (1%) which would be potentially of interest in the iron alloy market. The environmental sustainability of the process was also assessed by means of life cycle assessment and yielded an estimate that the highest impact was in the category of global warming potential with 0.42 kg carbon dioxide per kg recovered metal.

  2. Insights into carbon nanotube nucleation: cap formation governed by catalyst interfacial step flow.

    Science.gov (United States)

    Rao, Rahul; Sharma, Renu; Abild-Pedersen, Frank; Nørskov, Jens K; Harutyunyan, Avetik R

    2014-10-13

    In order to accommodate an increasing demand for carbon nanotubes (CNTs) with desirable characteristics one has to understand the origin of helicity of their structures. Here, through in situ microscopy we demonstrate that the nucleation of a carbon nanotube is initiated by the formation of the carbon cap. Nucleation begins with the formation of a graphene embryo that is bound between opposite step-edges on the nickel catalyst surface. The embryo grows larger as the step-edges migrate along the surface, leading to the formation of a curved carbon cap when the steps flow across the edges of adjacent facets. Further motion of the steps away from the catalyst tip with attached rims of the carbon cap generates the wall of the nanotube. Density Functional Theory calculations bring further insight into the process, showing that step flow occurs by surface self diffusion of the nickel atoms via a step-edge attachment-detachment mechanism. Since the cap forms first in the sequence of stages involved in growth, we suggest that it originates the helicity of the nanotube. Therefore, the angular distribution of catalyst facets could be exploited as a new parameter for controlling the curvature of the cap and, presumably, the helicity of the nanotube.

  3. Torsional Properties of Proprietary Heat Treated Nickel Titanium Rotary Instruments versus Conventional Nickel Titanium

    Science.gov (United States)

    2016-06-30

    rotational degrees (o) at separation were measured with a custom-built torsiometer instrument (Sabri Dental Enterprises, Inc, Downers Grove, IL) in...Torsional Properties of Proprietary Heat-Treated Nickel-Titanium Rotary Instruments versus Conventional Nickel-Titanium Principle Author...investigations at the USAF Dental Evaluation & Consultation Services (DECS) Laboratory. Responsible for calculating and analyzing all data collected during

  4. Nanosheet Supported Single-Metal Atom Bifunctional Catalyst for Overall Water Splitting.

    Science.gov (United States)

    Ling, Chongyi; Shi, Li; Ouyang, Yixin; Zeng, Xiao Cheng; Wang, Jinlan

    2017-08-09

    Nanosheet supported single-atom catalysts (SACs) can make full use of metal atoms and yet entail high selectivity and activity, and bifunctional catalysts can enable higher performance while lowering the cost than two separate unifunctional catalysts. Supported single-atom bifunctional catalysts are therefore of great economic interest and scientific importance. Here, on the basis of first-principles computations, we report a design of the first single-atom bifunctional eletrocatalyst, namely, isolated nickel atom supported on β 12 boron monolayer (Ni 1 /β 12 -BM), to achieve overall water splitting. This nanosheet supported SAC exhibits remarkable electrocatalytic performance with the computed overpotential for oxygen/hydrogen evolution reaction being just 0.40/0.06 V. The ab initio molecular dynamics simulation shows that the SAC can survive up to 800 K elevated temperature, while enacting a high energy barrier of 1.68 eV to prevent isolated Ni atoms from clustering. A viable experimental route for the synthesis of Ni 1 /β 12 -BM SAC is demonstrated from computer simulation. The desired nanosheet supported single-atom bifunctional catalysts not only show great potential for achieving overall water splitting but also offer cost-effective opportunities for advancing clean energy technology.

  5. Hydrogen production by ethanol steam reforming over Cu-Ni supported catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Vizcaino, A.J.; Carrero, A.; Calles, J.A. [Department of Chemical and Environmental Technology, Rey Juan Carlos University, Escuela Superior de Ciencias Experimentales y Tecnologia (ESCET), c/ Tulipan s/n, 28933 Mostoles (Spain)

    2007-07-15

    In the present work, Cu-Ni supported catalysts were tested in ethanol steam reforming reaction. Two commercial amorphous solids (SiO{sub 2} and {gamma}-Al{sub 2}O{sub 3}) and three synthesized materials (MCM-41, SBA-15 and ZSM-5 nanocrystalline) were used as support. A series of Cu-Ni/SiO{sub 2} catalysts with different Cu and Ni content were also prepared. It was found that aluminium containing supports favour ethanol dehydration to ethylene in the acid sites, which in turn, promotes the coke deactivation process. The highest hydrogen selectivity is achieved with the Cu-Ni/SBA-15 catalyst, due to a smaller metallic crystallite size. Nevertheless, the Cu-Ni/SiO{sub 2} catalyst showed the best catalytic performance, since a better equilibrium between high hydrogen selectivity and CO{sub 2}/CO{sub x} ratio is obtained. It was seen that nickel is the phase responsible for hydrogen production in a greater grade, although both CO production and coke deposition are decreased when copper is added to the catalyst. (author)

  6. Removal of methyl orange by heterogeneous Fenton catalysts prepared using glycerol as green reducing agent.

    Science.gov (United States)

    Trotte, Natália S F; Alzamora, M; Sánchez, D R; Carvalho, Nakédia M F

    2017-08-29

    This study aims to prepare environmentally friendly iron catalysts supported on silica, using glycerol as green reducing and stabilizing agent, for application in heterogeneous Fenton degradation of the pollutant dye methyl orange (MO). The catalysts were characterized by X-ray powder diffraction, atomic absorption spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analyses, Mössbauer and Fourier transform infrared spectroscopies, which revealed the formation of iron(II)/(III) oxalates from the oxidation of glycerol by the iron(III) nitrate precursor. Besides, iron oxihydroxide nanoparticles with superparamagnetic behavior were also formed. Iron catalysts prepared in the presence of nickel(II) or zinc(II) nitrates lead to the formation of the corresponding oxalates. The catalysts were able to degrade MO, efficiently in 180 min of reaction. Fe/SiO 2 furnished higher reaction rates, followed by Zn4Fe2/SiO 2 , which presented higher iron content as well as the smallest nanoparticles. Reaction parameters such as catalyst dosage, hydrogen peroxide concentration, pH and reaction temperature were investigated.

  7. A review of nickel hydrogen battery technology

    Science.gov (United States)

    Smithrick, John J.; Odonnell, Patricia M.

    1995-01-01

    This paper on nickel hydrogen batteries is an overview of the various nickel hydrogen battery design options, technical accomplishments, validation test results and trends. There is more than one nickel hydrogen battery design, each having its advantage for specific applications. The major battery designs are individual pressure vessel (IPV), common pressure vessel (CPV), bipolar and low pressure metal hydride. State-of-the-art (SOA) nickel hydrogen batteries are replacing nickel cadmium batteries in almost all geosynchronous orbit (GEO) applications requiring power above 1 kW. However, for the more severe low earth orbit (LEO) applications (greater than 30,000 cycles), the current cycle life of 4000 to 10,000 cycles at 60 percent DOD should be improved. A NASA Lewis Research Center innovative advanced design IPV nickel hydrogen cell led to a breakthrough in cycle life enabling LEO applications at deep depths of discharge (DOD). A trend for some future satellites is to increase the power level to greater than 6 kW. Another trend is to decrease the power to less than 1 kW for small low cost satellites. Hence, the challenge is to reduce battery mass, volume and cost. A key is to develop a light weight nickel electrode and alternate battery designs. A common pressure vessel (CPV) nickel hydrogen battery is emerging as a viable alternative to the IPV design. It has the advantage of reduced mass, volume and manufacturing costs. A 10 Ah CPV battery has successfully provided power on the relatively short lived Clementine Spacecraft. A bipolar nickel hydrogen battery design has been demonstrated (15,000 LEO cycles, 40 percent DOD). The advantage is also a significant reduction in volume, a modest reduction in mass, and like most bipolar designs, features a high pulse power capability. A low pressure aerospace nickel metal hydride battery cell has been developed and is on the market. It is a prismatic design which has the advantage of a significant reduction in volume and a

  8. Nickel allergy from adolescence to adulthood in the TOACS cohort

    DEFF Research Database (Denmark)

    Mortz, Charlotte G; Bindslev-Jensen, Carsten; Andersen, Klaus Ejner

    2013-01-01

    Background In 1995, we established a cohort of 1501 unselected eighth-grade schoolchildren to investigate the course of nickel allergy into adult life. Objectives To follow the course of nickel allergy and clinically relevant nickel dermatitis over 15 years from adolescence to adulthood, and the ......Background In 1995, we established a cohort of 1501 unselected eighth-grade schoolchildren to investigate the course of nickel allergy into adult life. Objectives To follow the course of nickel allergy and clinically relevant nickel dermatitis over 15 years from adolescence to adulthood...

  9. The effect of titanium nickel nitride decorated carbon nanotubes-reduced graphene oxide hybrid support for methanol oxidation

    Science.gov (United States)

    Liu, Gen; Pan, Zhanchang; Li, Wuyi; Yu, Ke; Xia, Guowei; Zhao, Qixiang; Shi, Shikun; Hu, Guanghui; Xiao, Chumin; Wei, Zhigang

    2017-07-01

    Titanium nickel nitride (TiNiN) decorated three-dimensional (3D) carbon nanotubes-reduced graphene oxide (CNT-rGO), a fancy 3D platinum (Pt)-based catalyst hybrid support, is prepared by a solvothermal process followed by a nitriding process, which is tested as anodic catalyst support for the methanol oxidation reaction (MOR). The structure, morphology and composition of the synthesized TiNiN/CNT-rGO exhibits a uniform particle dispersion with high purity and interpenetrating 3D network structure. Notably, Pt/TiNiN/CNT-rGO catalyst exhibits significantly improved catalytic activity and durability for methanol oxidation in comparison with Pt/CNT-rGO and conventional Pt/C (JM). The outstanding electrochemical performance was attributed to structure and properties. That is, the 3D CNT-rGO provided a fast transport network for charge-transfer and mass-transfer as well as TiNiN NPs with good synergistic effect and the strong electronic coupling between different domains in TiNiN/CNT-rGO, thus the catalytic activity of the novel catalyst is greatly improved. These results evidences 3D TiNiN/CNT-rGO as a promising catalyst support for a wide range of applications in fuel cells.

  10. Computer simulations of martensitic transformations in iron-nickel and nickel-aluminium alloys

    CERN Document Server

    Meyer, R J

    1998-01-01

    This thesis focuses on the martensitic transformations in iron-nickel and nickel-aluminum alloys. Molecular-dynamics simulations have been done, employing potentials based on the so-called embedded-atom method (EAM). These potentials were obtained by a fit of parameterized functions to experimental data of the elements iron, nickel, and aluminum as well as the intermetallic compound NiAl. Many aspects of the austenitic transformation in iron-nickel alloys and both, the martensitic and austenitic transformations, in nickel-aluminum alloys were reproduced well by the simulations. The results allow to draw conclusions on the reasons of differences and similarities in the behavior of both alloy systems.

  11. Ceramic catalyst materials

    Energy Technology Data Exchange (ETDEWEB)

    Sault, A.G.; Gardner, T.J. [Sandia National Laboratories, Albuquerque, NM (United States); Hanprasopwattanna, A.; Reardon, J.; Datye, A.K. [Univ. of New Mexico, Albuquerque, NM (United States)

    1995-08-01

    Hydrous titanium oxide (HTO) ion-exchange materials show great potential as ceramic catalyst supports due to an inherently high ion-exchange capacity which allows facile loading of catalytically active transition metal ions, and an ability to be cast as thin films on virtually any substrate. By coating titania and HTO materials onto inexpensive, high surface area substrates such as silica and alumina, the economics of using these materials is greatly improved, particularly for the HTO materials, which are substantially more expensive in the bulk form than other oxide supports. In addition, the development of thin film forms of these materials allows the catalytic and mechanical properties of the final catalyst formulation to be separately engineered. In order to fully realize the potential of thin film forms of titania and HTO, improved methods for the deposition and characterization of titania and HTO films on high surface area substrates are being developed. By varying deposition procedures, titania film thickness and substrate coverage can be varied from the submonolayer range to multilayer thicknesses on both silica and alumina. HTO films can also be formed, but the quality and reproducibility of these films is not nearly as good as for pure titania films. The films are characterized using a combination of isopropanol dehydration rate measurements, point of zero charge (PZC) measurements, BET surface area, transmission electron microscopy (TEM), and elemental analysis. In order to assess the effects of changes in film morphology on catalytic activity, the films are being loaded with MoO{sub 3} using either incipient wetness impregnation or ion-exchange of heptamolybdate anions followed by calcining. The MoO{sub 3} is then sulfided to form MOS{sub 2}, and tested for catalytic activity using pyrene hydrogenation and dibenzothiophene (DBT) desulfurization, model reactions that simulate reactions occurring during coal liquefaction.

  12. Evaluation of CO oxidation over Co3O4-supported NiO catalysts

    Science.gov (United States)

    Sie, Min-Chun; Jeng, Pei-Di; Chen, Pin-Hsuan; Wu, Ruei-Ci; Wang, Chen-Bin

    2017-09-01

    The process of doping NiO onto Co3O4 for achieving resistance to sintering and obtaining long-term stability of catalytic activity was examined herein. A sample of cobalt oxide (Co3O4) was prepared from Co(NO3)2.6H2O via precipitation by NaOH, and then calcined at 300 and 500 °C. The Co3O4-supported NiO catalysts were prepared by deposited precipitation of Ni(NO3)2.6H2O with NaOH added in a dropwise manner into the suspended Co3O4 solution with various loading of nickel. Then, oxidation with NaOCl was employed to obtain NiO/Co3O4 catalysts (weight loading of Ni: 0.1 ˜ 5 wt%). All of the samples were characterized by using XRD, SEM/TEM, BET, TPR and TGA techniques. Catalytic activities related to CO oxidation were tested from 0 to 200 °C in a self-designed fluidized micro-reactor. The results showed that the calcination temperature and loading of nickel were important parameters in the preparation process. With the lower calcined temperature and loading of nickel below 1 wt%, all the samples showed high initial catalytic activity for CO oxidation near room temperature. The synergistic effect can induce CO oxidation between NiO and Co3O4, and probably constitute a more suitable redox property for the 0.2%Ni/Co3O4 (C3) catalyst. Furthermore, only a slight decrease of CO conversion (less than 5%) was observed after 50 h of continuous reaction under 125 °C on this catalyst. The CO conversion could still remain above 75% after 50 h, which demonstrates that the 0.2%Ni/Co3O4 (C3) sample can function as a durable CO oxidation catalyst. We confirmed that our designed catalysts, based on tiny NiO nanoparticles, can be used as a component of a toxic gas abatement system.

  13. Development of GREET Catalyst Module

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhichao [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Cronauer, Donald C. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division

    2014-09-01

    Catalysts are critical inputs for many pathways that convert biomass into biofuels. Energy consumption and greenhouse gas (GHG) emissions during the production of catalysts and chemical inputs influence the life-cycle energy consumption, and GHG emissions of biofuels and need to be considered in biofuel life-cycle analysis (LCA). In this report, we develop energy and material flows for the production of three different catalysts (tar reforming, alcohol synthesis, Zeolite Socony Mobil-5 [ZSM-5]) and two chemicals (olivine, dimethyl ether of polyethylene glycol [DEPG]). These compounds and catalysts are now included in the Greenhouse Gases, Regulated Emissions and Energy Use in Transportation (GREET™) catalyst module. They were selected because they are consumed in existing U.S. Department of Energy (DOE) analyses of biofuel processes. For example, a thermochemical ethanol production pathway (indirect gasification and mixed alcohol synthesis) developed by the National Renewable Energy Laboratory (NREL) uses olivine, DEPG, and tar reforming and alcohol synthesis catalysts (Dutta et al., 2011). ZSM-5 can be used in biofuel production pathways such as catalytic upgrading of sugars into hydrocarbons (Biddy and Jones, 2013). Other uses for these compounds and catalysts are certainly possible. In this report, we document the data sources and methodology we used to develop material and energy flows for the catalysts and compounds in the GREET catalyst module. In Section 2 we focus on compounds used in the model Dutta et al. (2011) developed. In Section 3, we report material and energy flows associated with ZSM-5 production. Finally, in Section 4, we report results.

  14. Influence of Ce-precursor and fuel on structure and catalytic activity of combustion synthesized Ni/CeO{sub 2} catalysts for biogas oxidative steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Vita, Antonio, E-mail: antonio.vita@itae.cnr.it; Italiano, Cristina; Fabiano, Concetto; Laganà, Massimo; Pino, Lidia

    2015-08-01

    A series of nanosized Ni/CeO{sub 2} catalysts were prepared by Solution Combustion Synthesis (SCS) varying the fuel (oxalyldihydrazide, urea, carbohydrazide and glycerol), the cerium precursor (cerium nitrate and cerium ammonium nitrate) and the nickel loading (ranging between 3.1 and 15.6 wt%). The obtained powders were characterized by X-ray Diffraction (XRD), N{sub 2}-physisorption, CO-chemisorption, Temperature Programmed Reduction (H{sub 2}-TPR) and Scanning Electron Microscopy (SEM). The catalytic activity towards the Oxy Steam Reforming (OSR) of biogas was assessed. The selected operating variables have a strong influence on the nature of combustion and, in turn, on the morphological and structural properties of the synthesized catalysts. Particularly, the use of urea allows to improve nickel dispersion, surface area, particle size and reducibility of the catalysts, affecting positively the biogas OSR performances. - Highlights: • Synthesis of Ni/CeO{sub 2} nanopowders by quick and easy solution combustion synthesis. • The fuel and precursor drive the structural and morphological properties of the catalysts. • The use of urea as fuel allows to improve nickel dispersion, surface area and particle size. • Ni/CeO{sub 2} (7.8 wt% of Ni loading) powders synthesized by urea route exhibits high performances for the biogas OSR process.

  15. Chalcogen catalysts for polymer electrolyte fuel cell

    Science.gov (United States)

    Alonso-Vante, Nicolas [Buxerolles, FR; Zelenay, Piotr [Los Alamos, NM; Choi, Jong-Ho [Los Alamos, NM; Wieckowski, Andrzej [Champaign, IL; Cao, Dianxue [Urbana, IL

    2009-09-15

    A methanol-tolerant cathode catalyst and a membrane electrode assembly for fuel cells that includes such a cathode catalyst. The cathode catalyst includes a support having at least one transition metal in elemental form and a chalcogen disposed on the support. Methods of making the cathode catalyst and membrane electrode assembly are also described.

  16. Increasing the lifetime of fuel cell catalysts

    NARCIS (Netherlands)

    Latsuzbaia, R.

    2015-01-01

    In this thesis, I discuss a novel idea of fuel cell catalyst regeneration to increase lifetime of the PEM fuel cell electrode/catalyst operation and, therefore, reduce the catalyst costs. As many of the catalyst degradation mechanisms are difficult to avoid, the regeneration is alternative option to

  17. Cobalt release from inexpensive jewellery: has the use of cobalt replaced nickel following regulatory intervention?

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Jellesen, Morten S; Menné, Torkil

    2010-01-01

    Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure.......Before the introduction of the EU Nickel Directive, concern was raised that manufacturers of jewellery might turn from the use of nickel to cobalt following the regulatory intervention on nickel exposure....

  18. Impeded solid state reactions and transformations in ceramic catalysts supports and catalysts

    Directory of Open Access Journals (Sweden)

    Ernő E. Kiss

    2012-12-01

    Full Text Available Impeded chemical reactions and impeded polymorphous transformation in materials are discussed, as desired effects, for stabilization of ceramic catalyst supports and ceramic based catalysts. This paper gives a short overview about the possibilities of slowing down the aging processes in ceramic catalyst supports and catalysts. Special attention is given to alumina and titania based catalysts.

  19. Nickel-induced cytokine production from mononuclear cells in nickel-sensitive individuals and controls. Cytokine profiles in nickel-sensitive individuals with nickel allergy-related hand eczema before and after nickel challenge

    DEFF Research Database (Denmark)

    Borg, L; Christensen, J M; Kristiansen, J

    2000-01-01

    Exposure to nickel is a major cause of allergic contact dermatitis which is considered to be an inflammatory response induced by antigen-specific T cells. Here we describe the in vitro analysis of the nickel-specific T-cell-derived cytokine response of peripheral blood mononuclear cells from 35......, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) by quantitative ELISA. The analysis showed that the synthesis of IL-4 and IL-5 but not of IFN-gamma or TNF-alpha was significantly higher in the nickel-allergic individuals. The finding of preferential synthesis of Th2 cytokines...... differences were observed in the nickel-induced in vitro cytokine response during the exposure period. Our results indicate the possibility that IL-4 and IL-5 are involved in the pathogenesis of nickel-mediated contact dermatitis....

  20. Detection of airborne carbon nanotubes based on the reactivity of the embedded catalyst.

    Science.gov (United States)

    Neubauer, N; Kasper, G

    2015-01-01

    A previously described method for detecting catalyst particles in workplace air((1,2)) was applied to airborne carbon nanotubes (CNT). It infers the CNT concentration indirectly from the catalytic activity of metallic nanoparticles embedded as part of the CNT production process. Essentially, one samples airborne CNT onto a filter enclosed in a tiny chemical reactor and then initiates a gas-phase catalytic reaction on the sample. The change in concentration of one of the reactants is then determined by an IR sensor as measure of activity. The method requires a one-point calibration with a CNT sample of known mass. The suitability of the method was tested with nickel containing (25 or 38% by weight), well-characterized multi-walled CNT aerosols generated freshly in the lab for each experiment. Two chemical reactions were investigated, of which the oxidation of CO to CO2 at 470°C was found to be more effective, because nearly 100% of the nickel was exposed at that temperature by burning off the carbon, giving a linear relationship between CO conversion and nickel mass. Based on the investigated aerosols, a lower detection limit of 1 μg of sampled nickel was estimated. This translates into sampling times ranging from minutes to about one working day, depending on airborne CNT concentration and catalyst content, as well as sampling flow rate. The time for the subsequent chemical analysis is on the order of minutes, regardless of the time required to accumulate the sample and can be done on site.

  1. Effects of adding lanthanum to Ni/ZrO{sub 2} catalysts on ethanol steam reforming; Efeito da adicao de lantanio em catalisadores de Ni/ZrO{sub 2} aplicados na reacao de reforma a vapor de etanol

    Energy Technology Data Exchange (ETDEWEB)

    Profeti, Luciene Paula Roberto [Centro de Ciencias Agrarias, Universidade Federal do Espirito Santo, Alegre, ES (Brazil); Habitzheuter, Filipe; Assaf, Elisabete Moreira, E-mail: eassaf@iqsc.usp.br [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos, SP (Brazil)

    2012-07-01

    The catalytic performance of Ni/ZrO{sub 2} catalysts loaded with different lanthanum content for steam reforming of ethanol was investigated. Catalysts were characterized by BET surface area, X-ray diffraction, UV-vis spectroscopy, temperature programmed reduction, and X-ray absorption fine structure techniques. Results showed that lanthanum addition led to an increase in the degree of reduction of both NiO and nickel surface species interacting with the support, due to the higher dispersion effect. The best catalytic performance at 450 deg C was found for the Ni/12LZ catalyst, which exhibited an effluent gaseous mixture with the highest H{sub 2} yield. (author)

  2. Numerous dilemmas surrounding the 1917 nickel coins

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2017-01-01

    Full Text Available The Law on Extraordinary Loans Amounting to 200 Million Dinars and the Minting of Silver and Nickel Coins in 1916 was the legal basis for minting the 5-, 10-, and 20-para nickel coins of the Kingdom of Serbia featuring the year 1917 as their minting year. Some authors believe that these coins were minted in the Minting House in Paris, whereas the others agree that they were certainly minted in France, but in a still unidentified minting house. There are authors who in recent reference literature underline the possibility of their minting in the USA Gorham Company, in Providence, Rhode Island. These coins had all the characteristics of the nickel coins of the Kingdom of Serbia from 1883, 1884, 1904 and 1912. Although, according to the Law, the Minister of Finance was authorized to mint 10 million dinars of these nickel coins, only 5 million pieces in each denomination were actually minted, in the total nominal value of just 1,750,000 dinars. The general opinion is that after the war only a small amount of these nickel coins reached Serbia, because the ships transporting the Serbian coins from the minting house sank on their way. The only varying aspect in this explanation is the location from which the ships were sailing towards Corfu, i.e. from the USA or from France. These coins stopped being legal tender as of 30 November 1931.

  3. Mechanical Properties of Electrolyte Jet Electrodeposited Nickel Foam

    Directory of Open Access Journals (Sweden)

    Jinsong Chen

    2013-07-01

    Full Text Available Principles of the preparation of nickel foam by electrolyte jet electrodeposition were introduced, Nickel foam samples with different porosity were fabricated. Effect of different porosity on microhardness and uniaxial tensile properties of nickel foam was discussed. The results show that the microhardness of nickel foam is 320~400 HV, lower than entitative metal clearly. The lower the porosity of nickel foam, the higher the microhardness is. During the process of uniaxial tensile, nickel foam is characterized by three distinct regions, e.g. elastic deforming region, plastic plateau region and densification region. The higher the porosity of nickel foam, the lower the plastic plateau and the poorer the strength of nickel foam, accordingly

  4. Ethanol steam reforming over Ni/M{sub x}O{sub y}-Al{sub 2}O{sub 3} (M=Ce, La, Zr and Mg) catalysts: Influence of support on the hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Sanchez, M.C.; Navarro, R.M.; Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica, CSIC, C/ Marie Curie 2 Cantoblanco 28049 Madrid (Spain)

    2007-07-15

    Hydrogen production from ethanol reforming over alumina-supported nickel catalysts modified with Ce, Mg, Zr and La was studied. Characterization of catalysts by XRD, TPR, XRD and TPD of NH{sub 3} revealed changes in the acidity, nickel dispersion and nickel-support interaction with the type of the modifier added to Al{sub 2}O{sub 3}. The acidity of catalysts containing Mg, Ce, La and Zr additives decreased with respect to that supported on bare Al{sub 2}O{sub 3}. The trend of metal dispersion as derived from XRD and H{sub 2} chemisorption results followed the order: La{sub 2}O{sub 3}-Al{sub 2}O{sub 3}>MgO-Al{sub 2}O{sub 3}>CeO{sub 2}-Al{sub 2}O{sub 3}>Al{sub 2}O{sub 3}>ZrO{sub 2}-Al{sub 2}O{sub 3}. TPR and XPS analyses indicate the development of strong interactions between nickel species and ZrO{sub 2}, La{sub 2}O{sub 3} and CeO{sub 2} oxides added to supports. The activity measurements coupled with the physicochemical characterization data indicated the different catalysts functionality that influences on their reforming activity. Thus, the higher reforming activity for Mg-modified catalyst respect to bare Al{sub 2}O{sub 3} was explained in terms of the lower acidity and better dispersion achieved in the former, while for Ce- and Zr-promoted catalysts the improvement in intrinsic activity was ascribed to the enhancement of water adsorption/dissociation on the Ni-Ce and Ni-Zr interfaces developed on these catalysts. On the other hand, the lower intrinsic activity of La-added catalyst was explained in terms of the dilution effect caused by the presence of lanthanum on Ni surfaces. Characterization of catalysts after reaction showed differences on the amount and type of coke deposited on catalysts surfaces. La and Ce additives were found to prevent the formation of carbon filaments on nickel surfaces, which is responsible of the changes in product selectivities with reaction time observed on Ni/Al{sub 2}O{sub 3}, Ni/ZrO{sub 2}-Al{sub 2}O{sub 3} and Ni/MgO-Al{sub 2}O

  5. Biomass processing over gold catalysts

    CERN Document Server

    Simakova, Olga A; Murzin, Dmitry Yu

    2014-01-01

    The book describes the valorization of biomass-derived compounds over gold catalysts. Since biomass is a rich renewable feedstock for diverse platform molecules, including those currently derived from petroleum, the interest in various transformation routes has become intense. Catalytic conversion of biomass is one of the main approaches to improving the economic viability of biorefineries.  In addition, Gold catalysts were found to have outstanding activity and selectivity in many key reactions. This book collects information about transformations of the most promising and important compounds derived from cellulose, hemicelluloses, and woody biomass extractives. Since gold catalysts possess high stability under oxidative conditions, selective oxidation reactions were discussed more thoroughly than other critical reactions such as partial hydrogenation, acetalization, and isomerization. The influence of reaction conditions, the role of the catalyst, and the advantages and disadvantages of using gold are pre...

  6. Comparison between Ni-Rh/gadolinia doped ceria catalysts in reforming of propane for anode implementations in intermediate solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Boaro, M.; Pappacena, A. [Universita di Udine, Dipartimento di Scienze e Tecnologie Chimiche, via Cotonificio 108, 33100 Udine (Italy); Modafferi, V.; Frontera, P. [Universita Mediterranea, Dipartimento Meccanica e Materiali, Feo di Vito, 89060 Reggio Calabria (Italy); Llorca, J. [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain); Baglio, V.; Frusteri, F. [CNR-ITAE ' ' Nicola Giordano' ' , Salita S. Lucia 5, 98126 Messina (Italy); Trovarelli, A. [Universita di Udine, Dipartimento di Scienze e Tecnologie Chimiche, via Cotonificio 108, 33100 Udine (Italy); INSTM-Consorzio Interuniversitario Nazionale per le Scienze e Tecnologie dei Materiali, via Giusti 9, 50121 Firenze (Italy); Antonucci, P.L. [Universita Mediterranea, Dipartimento Meccanica e Materiali, Feo di Vito, 89060 Reggio Calabria (Italy); INSTM-Consorzio Interuniversitario Nazionale per le Scienze e Tecnologie dei Materiali, via Giusti 9, 50121 Firenze (Italy)

    2010-01-15

    Steam and autothermal reforming of propane over Ni-Rh/GDC catalysts prepared by coprecipitation and by Pechini method were investigated in the temperature range 873-1073 K. The weight ratio for Ni, Rh and Ce{sub 0.8}Gd{sub 0.2}O{sub 2} (45:5:50) and the operating temperatures were chosen in order to gain propaedeutical information on fuel reactivity under typical intermediate solid oxide fuel cell (IT-SOFC) operating conditions. The Pechini synthesis allows to obtain catalysts with lower surface area, smaller nickel crystallites and a bimodal distribution of rhodium in comparison to the coprecipitation method. Despite the different methods of synthesis lead to catalysts with different morphological and structural properties, the activity of catalysts is quite similar. At reaction temperature higher than 973 K, under both steam reforming (SR) and autothermal reforming (ATR), the catalysts show high propane conversion and syngas (H{sub 2} + CO) productivity. Deactivation of catalysts was observed at 873 and 973 K under SR conditions due to coke formation. In ATR, coke formation was almost completely depressed and the catalysts resulted to be very stable even at low reaction temperature (873 K). In SR coke formation occurs with higher rate on the catalyst having higher Ni dispersion, probably since propane cracking reaction is the pre-eminent phenomenon in promoting coke formation. (author)

  7. A comparative parametric study of a catalytic plate methane reformer coated with segmented and continuous layers of combustion catalyst for hydrogen production

    Science.gov (United States)

    Mundhwa, Mayur; Parmar, Rajesh D.; Thurgood, Christopher P.

    2017-03-01

    A parametric comparison study is carried out between segmented and conventional continuous layer configurations of the coated combustion-catalyst to investigate their influence on the performance of methane steam reforming (MSR) for hydrogen production in a catalytic plate reactor (CPR). MSR is simulated on one side of a thin plate over a continuous layer of nickel-alumina catalyst by implementing an experimentally validated surface microkinetic model. Required thermal energy for the MSR reaction is supplied by simulating catalytic methane combustion (CMC) on the opposite side of the plate over segmented and continuous layer of a platinum-alumina catalyst by implementing power law rate model. The simulation results of both coating configurations of the combustion-catalyst are compared using the following parameters: (1) co-flow and counter-flow modes between CMC and MSR, (2) gas hourly space velocity and (3) reforming-catalyst thickness. The study explains why CPR designed with the segmented combustion-catalyst and co-flow mode shows superior performance not only in terms of high hydrogen production but also in terms of minimizing the maximum reactor plate temperature and thermal hot-spots. The study shows that the segmented coating requires 7% to 8% less combustion-side feed flow and 70% less combustion-catalyst to produce the required flow of hydrogen (29.80 mol/h) on the reforming-side to feed a 1 kW fuel-cell compared to the conventional continuous coating of the combustion-catalyst.

  8. An effective Pd-Ni(2)P/C anode catalyst for direct formic acid fuel cells.

    Science.gov (United States)

    Chang, Jinfa; Feng, Ligang; Liu, Changpeng; Xing, Wei; Hu, Xile

    2014-01-03

    The direct formic acid fuel cell is an emerging energy conversion device for which palladium is considered as the state-of-the-art anode catalyst. In this communication, we show that the activity and stability of palladium for formic acid oxidation can be significantly enhanced using nickel phosphide (Ni(2)P) nanoparticles as a cocatalyst. X-ray photoelectron spectroscopy (XPS) reveals a strong electronic interaction between Ni(2)P and Pd. A direct formic acid fuel cell incorporating the best Pd–Ni(2)P anode catalyst exhibits a power density of 550 mWcm(-2), which is 3.5 times of that of an analogous device using a commercial Pd anode catalyst.

  9. Study of NiMoS mixed phase from catalyst precursors in residue slurry-bed hydrocracking

    Science.gov (United States)

    Du, Juntao; Deng, Wenan; Li, Chuan; Zhang, Zailong; Sun, Qiang; Cao, Xiangpeng; Yang, Tengfei

    2017-03-01

    The evolution and role of NiMoS structures from catalyst precursors on residue hydrocracking was investigated. NiMoS mixed phase played important roles in unsupported catalyst and heavy oil development, such as synergy effect and coke inhibiting. The oil-soluble molybdenum naphthenate and nickel naphthenate were chosen as catalyst precursors. The mixtures of the precursor were compared to those of other monometallic oil-soluble precursor in an effort to evaluate the evolution and role of NiMoS phase in the slurry bed hydrocracking of heavy oil. The presence of NiMoS phase were characterized by X-ray diffraction (XRD), TEM and XPS. The series of tests in the slurry-phase reactor was to confirm the synergy effect of NiMoS mixed phase.

  10. Photocatalytic Hydrogen Production using Polymeric Carbon Nitride with a Hydrogenase and a Bioinspired Synthetic Ni Catalyst**

    OpenAIRE

    Caputo, Christine Amanda; Gross, Manuela A.; Lau, Vincent W; Cavazza, Christine; Lotsch, Bettina V.; Reisner, Erwin

    2014-01-01

    Solar-light-driven H2 production in water with a [NiFeSe]-hydrogenase (H2ase) and a bioinspired synthetic nickel catalyst (NiP) in combination with a heptazine carbon nitride polymer, melon (CNx), is reported. The semibiological and purely synthetic systems show catalytic activity during solar light irradiation with turnover numbers (TONs) of more than 50 000 mol H2 (mol H2ase)?1 and approximately 155 mol H2 (mol NiP)?1 in redox-mediator-free aqueous solution at pH 6 and 4.5, respectively. Bo...

  11. Facile synthesis of a large quantity of graphene by chemical vapor deposition: an advanced catalyst carrier.

    Science.gov (United States)

    Shan, Changsheng; Tang, Hao; Wong, Tailun; He, Lifang; Lee, Shuit-Tong

    2012-05-08

    A large quantity of highly conductive graphene was prepared by a novel CVD method with nickel powder as a template and PMMA as carbon source. With Pt as a model, PtNP-modified graphene showed much better electrocatalytic ability for O(2) and methanol than PtNP-reduced graphene oxide (RGO) and commercial Pt/C, showing that this graphene is a better catalyst carrier than RGO and commercial carbon. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Facile synthesis of a large quantity of graphene by chemical vapor deposition: an advanced catalyst carrier

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Changsheng; Tang, Hao; Wong, Tailun; He, Lifang; Lee, Shuit-Tong [Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong (China)

    2012-05-08

    A large quantity of highly conductive graphene was prepared by a novel CVD method with nickel powder as a template and PMMA as carbon source. With Pt as a model, PtNP-modified graphene showed much better electrocatalytic ability for O{sub 2} and methanol than PtNP-reduced graphene oxide (RGO) and commercial Pt/C, showing that this graphene is a better catalyst carrier than RGO and commercial carbon. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Coupling molecular catalysts with nanostructured surfaces for efficient solar fuel production

    Science.gov (United States)

    Jin, Tong

    Solar fuel generation via carbon dioxide (CO2) reduction is a promising approach to meet the increasing global demand for energy and to minimize the impact of energy consumption on climate change. However, CO2 is thermodynamically stable; its activation often requires the use of appropriate catalysts. In particular, molecular catalysts with well-defined structures and tunability have shown excellent activity in photochemical CO2 reduction. These homogenous catalysts, however, suffer from poor stability under photochemical conditions and difficulty in recycling from the reaction media. Heterogenized molecular catalysts, particularly those prepared by coupling molecular catalysts with solid-state surfaces, have attracted more attention in recent years as potential solutions to address the issues associated with molecular catalysts. In this work, solar CO2 reduction is investigated using systems coupling molecular catalysts with robust nanostructured surfaces. In Chapter 2, heterogenization of macrocyclic cobalt(III) and nickel (II) complexes on mesoporous silica surface was achieved by different methods. Direct ligand derivatization significantly lowered the catalytic activity of Co(III) complex, while grafting the Co(III) complex onto silica surface through Si-O-Co linkage resulted in hybrid catalysts with excellent activity in CO2 reduction in the presence of p-terphenyl as a molecular photosensitizer. An interesting loading effect was observed, in which the optimal activity was achieved at a medium Co(III) surface density. Heterogenization of the Ni(II) complex on silica surface has also been implemented, the poor photocatalytic activity of the hybrid catalyst can be attributed to the intrinsic nature of the homogeneous analogue. This study highlighted the importance of appropriate linking strategies in preparing functional heterogenized molecular catalysts. Coupling molecular complexes with light-harvesting surfaces could avoid the use of expensive molecular

  14. Laser synthesis, structure and chemical properties of colloidal nickel-molybdenum nanoparticles for the substitution of noble metals in heterogeneous catalysis.

    Science.gov (United States)

    Marzun, Galina; Levish, Alexander; Mackert, Viktor; Kallio, Tanja; Barcikowski, Stephan; Wagener, Philipp

    2017-03-01

    Platinum and iridium are rare and expensive noble metals that are used as catalysts for different sectors including in heterogeneous chemical automotive emission catalysis and electrochemical energy conversion. Nickel and its alloys are promising materials to substitute noble metals. Nickel based materials are cost-effective with good availability and show comparable catalytic performances. The nickel-molybdenum system is a very interesting alternative to platinum in water electrolysis. We produced ligand-free nickel-molybdenum nanoparticles by laser ablation in water and acetone. Our results show that segregated particles were formed in water due to the oxidation of the metals. X-ray diffraction shows a significant change in the lattice parameter due to a diffusion of molybdenum atoms into the nickel lattice with increasing activity in the electrochemical oxygen evolution reaction. Even though the solubility of molecular oxygen in acetone is higher than in water, there were no oxides and a more homogeneous metal distribution in the particles in acetone as seen by TEM-EDX. This showed that dissolved molecular oxygen does not control oxide formation. Overall, the laser ablation of pressed micro particulate mixtures in liquids offers a combinational synthesis approach that allows the screening of alloy nanoparticles for catalytic testing and can convert micro-mixtures into nano-alloys. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. 40 CFR 721.5325 - Nickel acrylate complex.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Nickel acrylate complex. 721.5325... Substances § 721.5325 Nickel acrylate complex. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance nickel acrylate complex (PMN P-85-1034) is subject to reporting under...

  16. Absence of Nickel in Detergents Confirmed by Dimethylglyoxime Spot Test

    Directory of Open Access Journals (Sweden)

    D S Krupashankar

    1987-01-01

    Full Text Available Reports differ greatly as to the significance of nickel in detergents as a cause of dermatitis. Dimethylglyoe spot test was negative for nickel with various detergents. It seems therefore that nickel is not an important cause of detergent induced dermatitis in India.

  17. Chemistry of nickel and copper production from sulphide ores | Love ...

    African Journals Online (AJOL)

    Nickel is one of Zimbabwe's principle metallurgical exports. It is processed to a very high level of purity and hence has a high value. The economics of nickel production can be difficult, as the selling value of nickel varies tremendously with time, from a low of US$ 3 900 per ton in late 1998 to US$ 10 100 per ton in May 2000, ...

  18. Effects of repeated skin exposure to low nickel concentrations

    DEFF Research Database (Denmark)

    Nielsen, N H; Menné, T; Kristiansen, J

    1999-01-01

    We studied the effects of repeated daily exposure to low nickel concentrations on the hands of patients with hand eczema and nickel allergy. The concentrations used were chosen to represent the range of trace to moderate occupational nickel exposure. The study was double-blinded and placebo...

  19. Nickel Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review

    Science.gov (United States)

    1998-04-01

    ceramics, disinfectants , varnish, magnets, batteries, ink, dyes, and vacuum tubes (USPHS 1977). Non-occupational exposure to nickel and its...nickel for industrial applications (USPHS 1993). In 1988, the United States imported 186,000 tons of primary nickel; Canada supplied 58% of the...terrestrial plants is complexed with polycarboxylic acids and pectins, although phosphate groups may also participate (Kasprzak 1987). In

  20. Kinetics of oxidation of nickel (II) aza macrocycles by ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 112; Issue 5. Kinetics of oxidation of nickel(II) aza macrocycles by peroxydisulphate in aqueous media ... The kinetics of the oxidation of nickel (II) hexaaza and nickel (II) pentaaza macrocycles by the peroxydisulphate anion, S2O8 2-, were studied in aqueous media.

  1. Effect of Ca, Ce or K oxide addition on the activity of Ni/SiO{sub 2} catalysts for the methane decomposition reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Beatriz; Torres-Garcia, Enelio [Instituto Mexicano del Petroleo, Programa de Procesos y Reactores, Eje C. 152, Mexico, D.F., C.P. 07730 (Mexico); Valenzuela, Miguel A.; Palacios, Jorge [Instituto Politecnico Nacional-ESIQIE, Lab. Catalisis y Materiales, Zacatenco, Mexico, D.F., C.P. 07738 (Mexico)

    2010-11-15

    To increase the activity and stability of Ni/SiO{sub 2} catalysts, a series of Ni-Ca, Ni-K and Ni-Ce promoted catalysts were prepared by successive impregnations. The textural properties, reducibility and catalytic performance in the methane decomposition reaction were investigated. The catalyst containing 30 wt.% Ni and 30 wt.% cerium oxide greatly increased the conversion of methane (90% of equilibrium value) and improved the stability, whereas the Ni-K and Ni-Ca were less active and stable than the Ni/SiO{sub 2} catalyst. The results suggest that Ce addition prevents the sintering of nickel particles during reduction process maintaining a random distribution between the silica and cerium oxide improving the distribution and migration of deposited carbon. (author)

  2. The innovation catalysts.

    Science.gov (United States)

    Martin, Roger L

    2011-06-01

    A few years ago the software development company Intuit realized that it needed a new approach to galvanizing customers. The company's Net Promoter Score was faltering, and customer recommendations of new products were especially disappointing. Intuit decided to hold a two-day, off-site meeting for the company's top 300 managers with a focus on the role of design in innovation. One of the days was dedicated to a program called Design for Delight. The centerpiece of the day was a PowerPoint presentation by Intuit founder Scott Cook, who realized midway through that he was no Steve Jobs: The managers listened dutifully, but there was little energy in the room. By contrast, a subsequent exercise in which the participants worked through a design challenge by creating prototypes, getting feedback, iterating, and refining, had them mesmerized. The eventual result was the creation of a team of nine design-thinking coaches--"innovation catalysts"--from across Intuit who were made available to help any work group create prototypes, run experiments, and learn from customers. The process includes a "painstorm" (to determine the customer's greatest pain point), a "soljam" (to generate and then winnow possible solutions), and a "code-jam" (to write code "good enough" to take to customers within two weeks). Design for Delight has enabled employees throughout Intuit to move from satisfying customers to delighting them.

  3. Anodic stripping voltammetry of nickel ions and nickel hydroxide nanoparticles at boron-doped diamond electrodes

    Science.gov (United States)

    Musyarofah, N. R. R.; Gunlazuardi, J.; Einaga, Y.; Ivandini, T. A.

    2017-04-01

    Anodic stripping voltammetry (ASV) of nickel ions in phosphate buffer solution (PBS) have been investigated at boron-doped diamond (BDD) electrodes. The deposition potential at 0.1 V (vs. Ag/AgCl) for 300 s in 0.1 M PBS pH 3 was found as the optimum condition. The condition was applied for the determination of nickel contained in nickel hydroxide nanoparticles. A linear calibration curve can be achieved of Ni(OH)2-NPs in the concentration range of x to x mM with an estimated limit of detection (LOD) of 5.73 × 10-6 mol/L.

  4. Steam reforming of biomass gasification tar using benzene as a model compound over various Ni supported metal oxide catalysts.

    Science.gov (United States)

    Park, Hyun Ju; Park, Sung Hoon; Sohn, Jung Min; Park, Junhong; Jeon, Jong-Ki; Kim, Seung-Soo; Park, Young-Kwon

    2010-01-01

    The steam reforming of benzene as a model compound of biomass gasification tar was carried out over various Ni/metal oxide catalysts. The effects of the support, temperature, Ni-precursor, Ni loading and reaction time were examined, and their catalytic performance was compared with that of a commercial Ni catalyst. Among the Ni/metal oxide catalysts used, 15 wt% Ni/CeO(2)(75%)-ZrO(2)(25%) showed the highest catalytic performance owing to its greater redox characteristics and increased surface area, irrespective of the reaction temperature. The catalytic activity of 15 wt% Ni/CeO(2)(75%)-ZrO(2)(25%) was higher than that of the commercial Ni catalyst. Moreover, the catalyst activity was retained due to its excellent resistance to coke deposition even after 5h. The Ni-precursor played a critical role in the catalytic activity. With the exception of nickel nitrate, all the Ni-precursors (chloride and sulfate) caused deactivation of the catalyst.

  5. Origin of low temperature deactivation of Ni5Ga3 nanoparticles as catalyst for methanol synthesis

    DEFF Research Database (Denmark)

    Gardini, Diego; Sharafutdinov, Irek; Damsgaard, Christian Danvad

    In an effort to find alternative energy sources capable to compete with fossil fuels, methanol synthesis could represent a realistic solution to store “green” hydrogen produced from electrolysis or photo-induced water splitting. Recently, density functional theory (DFT) calculations [1] proposed Ni......-Ga alloys as active catalysts for methanol production from syngas mixtures and Ni-Ga nanoparticles supported on highly porous silica have been prepared using an incipient wetness impregnation technique from a solution of nickel and gallium nitrates [2]. Tests conducted in a fixed-bed reactor showed...... that the highest methanol yield is obtained with a Ni5Ga3 alloy exposed to a 25% CO2 – 75% H2 reaction mixture at 210 °C [2]. Under these experimental conditions, the catalyst is found to lose 35% of its activity after 20 hours of continuous testing at both 1 and 5 Bars. Although in situ XRD and EXAFS studies [3...

  6. Hydrogen production from ethanol steam reforming over cerium and nickel based oxyhydrides

    Energy Technology Data Exchange (ETDEWEB)

    Jalowiecki-Duhamel, L.; Pirez, C.; Capron, M.; Dumeignil, F.; Payen, E. [Unite de Catalyse et de Chimie du Solide, UMR CNRS 8181, Bat. C3, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France)

    2010-12-15

    Hydrogen production from ethanol steam reforming (H{sub 2}O/C{sub 2}H{sub 5}OH = 3) was investigated over cerium-nickel CeNi{sub x}O{sub Y} (0 < x {<=} 5) mixed oxide catalysts. The influence of different parameters was analysed, such as reaction temperature, Ni content and in-situ pre-treatment in H{sub 2}. While an ethanol conversion of 100% is reached at 400 C, a stable activity i.e., ethanol conversion, and H{sub 2} selectivity can be obtained at very low temperature (200 C) when the solid is previously in-situ treated in H{sub 2} in a temperature range between 200 C and 300 C. After such a treatment, the solids studied are hydrogen reservoirs, called oxyhydrides, with the presence of hydrogen species of hydride nature in the anionic vacancies of the solid. Different physicochemical techniques, including XPS, ion sputtering, XRD, TPR were used to characterize the catalysts. Depending on the composition and metal loading, a solid solution and/or a highly dispersed nickel oxide in ceria can be obtained. Ion sputtering followed by XPS analysis allowed estimating the size of NiO nanoparticles (2-3 nm) present in the compounds, too small to be detected by XRD. The characterization of CeNi{sub x}O{sub Y} solids, evidenced the existence of high interactions between Ce and Ni cations located either in the solid solution of cerium-nickel or at the interface between NiO and CeO{sub 2} (or solid solution). The active nickel species belonging to the small particles and/or to the solid solution, participating actively in the catalytic reaction, present the characteristic of being able to be reduced and reoxidized easily and reversibly (redox process), allowed by their close interaction with Ce species. Finally, correlations among the species present in the solid, and the catalytic performances are discussed, and an active site based on the formation of anionic vacancies and a mechanism involving a heterolytic abstraction of a hydride species from ethanol are envisaged

  7. Metallic Iron-Nickel Sulfide Ultrathin Nanosheets As a Highly Active Electrocatalyst for Hydrogen Evolution Reaction in Acidic Media.

    Science.gov (United States)

    Long, Xia; Li, Guixia; Wang, Zilong; Zhu, HouYu; Zhang, Teng; Xiao, Shuang; Guo, Wenyue; Yang, Shihe

    2015-09-23

    We report on the synthesis of iron-nickel sulfide (INS) ultrathin nanosheets by topotactic conversion from a hydroxide precursor. The INS nanosheets exhibit excellent activity and stability in strong acidic solutions as a hydrogen evolution reaction (HER) catalyst, lending an attractive alternative to the Pt catalyst. The metallic α-INS nanosheets show an even lower overpotential of 105 mV at 10 mA/cm(2) and a smaller Tafel slope of 40 mV/dec. With the help of DFT calculations, the high specific surface area, facile ion transport and charge transfer, abundant electrochemical active sites, suitable H(+) adsorption, and H2 formation kinetics and energetics are proposed to contribute to the high activity of the INS ultrathin nanosheets toward HER.

  8. Nickel release from inexpensive jewelry and hair clasps purchased in an EU country - Are consumers sufficiently protected from nickel exposure?

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Menné, Torkil; Johansen, Jeanne Duus

    2009-01-01

    BACKGROUND: Nickel allergic subjects are at risk factor of acquiring hand eczema. In 1990 and 1994, respectively, Denmark and member states in the EU regulated nickel release from selected consumer products. The intention was that the nickel epidemic could be controlled and prevented if the gener...

  9. Hot corrosion of TD nickel and TD nickel chromium in a high velocity gas stream.

    Science.gov (United States)

    Sanders, W. A.; Probst, H. B.

    1971-01-01

    Results of cyclical tests of TD nickel (2% thoria-dispersed nickel) and TD nickel chromium (2% thoria-dispersed nickel-20% chromium alloy) 1.5 mm (60 mil) sheet specimens for susceptibility to hot corrosion in a Mach 0.5 gas stream of Jet A-1 fuel combustion products containing 2 ppm sea salt. Tests as long as 500 one-hour cycles between room temperature and specimen hot zone temperatures of 899 C (1650 F), 982 C (1800 F), and 1149 C (2100 F) were performed. Evidence of hot corrosion was found for both materials in the 899 C (1650 F) and 982 C (1800 F) tests, but not at 1149 C (2100 F). It was concluded that because of high metal thickness losses neither alloy in sheet form is suitable for long-time engine application in a hot corrosion environment at temperatures of 982 C (1800 F) or above.

  10. Pt-Ni and Pt-M-Ni (M = Ru, Sn Anode Catalysts for Low-Temperature Acidic Direct Alcohol Fuel Cells: A Review

    Directory of Open Access Journals (Sweden)

    Ermete Antolini

    2017-01-01

    Full Text Available In view of a possible use as anode materials in acidic direct alcohol fuel cells, the electro-catalytic activity of Pt-Ni and Pt-M-Ni (M = Ru, Sn catalysts for methanol and ethanol oxidation has been widely investigated. An overview of literature data regarding the effect of the addition of Ni to Pt and Pt-M on the methanol and ethanol oxidation activity in acid environment of the resulting binary and ternary Ni-containing Pt-based catalysts is presented, highlighting the effect of alloyed and non-alloyed nickel on the catalytic activity of these materials.

  11. Carbon deposition in the Bosch process with ruthenium and ruthenium-iron alloy catalysts. M.S. Thesis. Final Report, Jan. 1981 - Jul. 1982

    Science.gov (United States)

    Manning, M. P.; Reid, R. C.; Sophonpanich, C.

    1982-01-01

    The effectiveness of ruthenium and the alloys 50Ru50Fe and 33Ru67Fe as alternatives to iron, nickel, and cobalt catalysts in recovering oxygen from metabolic carbon dioxide was investigated. Carbon deposition boundaries over the unsupported alloys are reported. Experiments were also carried out over 50Ru50Fe and 97Ru3Fe3 catalysts supported on gamma-alumina to determine their performance in the synthesis of low molecular weight olefins. High production of ethylene and propylene would be beneficial for an improvement of an overall Bosch process, as a gas phase containing high olefin content would enhance carbon deposition in a Bosch reactor.

  12. Influence of excess sodium ions on the specific surface area formation in a NiO-Al2O3 catalyst prepared by different methods

    Directory of Open Access Journals (Sweden)

    Lazić M.M.

    2008-01-01

    Full Text Available The influence of sodium ions on the specific surface area of a NiO-Al2O3 catalyst in dependence of nickel loading (5, 10, and 20 wt% Ni, temperature of heat treatment (400, 700 and 1100oC and the method of sample preparation was investigated. Low temperature nitrogen adsorption (LTNA, X-ray diffraction (XRD and scanning electron microscopy (SEM were applied for sample characterization. Dramatic differences in the specific surface area were registered between non-rinsed and rinsed Al2O3 and NiO-Al2O3 samples. The lagged sodium ions promote sintering of non-rinsed catalyst samples.

  13. Structure of ultradisperse nickel particles produced by the thermolysis of nickel formate-monoethanol amine complexes

    Energy Technology Data Exchange (ETDEWEB)

    Khvorov, M.M.; Dudchenko, A.K.; Khimchenko, IU.I.

    1986-05-01

    Histograms of the size distribution of ultradisperse nickel particles produced by the thermolysis of amine complexes are plotted using dark-field and light-field electron microscopy data. It is found that the size distribution can be adequately approximated by logarithmically probabilistic functions. The ultradisperse nickel particles feature several types of structure, i.e., faceted stable single crystals coated by an organic film, small aggregates of such crystals, large stable globules, and hexahedral and trihedral crystals. 8 references.

  14. Bio-inspired MOF-based Catalysts for Lignin Valorization.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Stavila, Vitalie; Ramakrishnan, Parthasarathi; Davis, Ryan Wesley

    2014-09-01

    Lignin is a potentially plentiful source of renewable organics, with %7E50Mtons/yr produced by the pulp/paper industry and 200-300 Mtons/yr projected production by a US biofuels industry. This industry must process approximately 1 billion tons of biomass to meet the US Renewable Fuel goals. However, there are currently no efficient processes for converting lignin to value-added chemicals and drop-in fuels. Lignin is therefore an opportunity for production of valuable renewable chemicals, but presents staggering technical and economic challenges due to the quantities of material involved and the strong chemical bonds comprising this polymer. Aggressive chemistries and high temperatures are required to degrade lignin without catalysts. Moreover, chemical non-uniformity among lignins leads to complex product mixtures that tend to repolymerize. Conventional petrochemical approaches (pyrolysis, catalytic cracking, gasification) are energy intensive (400-800 degC), require complicated separations, and remove valuable chemical functionality. Low-temperature (25-200 degC) alternatives are clearly desirable, but enzymes are thermally fragile and incompatible with liquid organic compounds, making them impractical for large-scale biorefining. Alternatively, homogeneous catalysts, such as recently developed vanadium complexes, must be separated from product mixtures, while many heterogenous catalysts involve costly noble metals. The objective of this project is to demonstrate proof of concept that an entirely new class of biomimetic, efficient, and industrially robust synthetic catalysts based on nanoporous Metal- Organic Frameworks (MOFs) can be developed. Although catalytic MOFs are known, catalysis of bond cleavage reactions needed for lignin degradation is completely unexplored. Thus, fundamental research is required that industry and most sponsoring agencies are currently unwilling to undertake. We introduce MOFs infiltrated with titanium and nickel species as catalysts

  15. Nickel allergy and relationship with Staphylococcus aureus in atopic dermatitis.

    Science.gov (United States)

    Bogdali, Anna M; Anna, Bogdali M; Grazyna, Antoszczyk; Wojciech, Dyga; Aleksander, Obtulowicz; Anna, Bialecka; Andrzej, Kasprowicz; Zofia, Magnowska; Krystyna, Obtulowicz

    2016-01-01

    The increase of nickel air pollution is supposed to frequent side effects of nickel action related to virulence potential of Staphylococcus aureus in patients with nickel allergy in atopic dermatitis. The goal was to investigate the relationship between nickel allergy and infection by S. aureus in atopic dermatitis. Nickel allergy was confirmed in atopic patients and excluded in healthy volunteers using patch testing. Infection by S. aureus was tested in atopic patients and healthy volunteers by use of API Staph system. The specific IgE for staphylococcal enterotoxin A and B were measured. Secretion of IFN-g, IL-2, IL-13 by PBMC under nickel sulfate and the enterotoxins A and B stimulations were studied with ELISpot. We found the increased number of infections by S. aureus in atopic patients with nickel allergy in comparison to atopic patients and healthy volunteers without nickel allergy. The elevated secretion of IL-2 under nickel sulfate stimulation in vitro was exclusively found in atopic patients with nickel allergy infected by S. aureus. Our data suggest that nickel allergy and infection by S. aureus are linked in atopic dermatitis. Copyright © 2015 Elsevier GmbH. All rights reserved.

  16. The role of oxidative stress in nickel and chromate genotoxicity.

    Science.gov (United States)

    Costa, Max; Salnikow, Konstantin; Sutherland, Jessica E; Broday, Limor; Peng, Wu; Zhang, Qunwei; Kluz, Thomas

    2002-01-01

    Some general principles regarding oxidative stress and molecular responses to toxic metals are presented in this manuscript. The remainder of the manuscript, however, will focus on the role of oxidative stress in particulate nickel-induced genetic damage and mutations. The phagocytosis of particulate nickel compounds and the dissolution of the particles inside the cell and the resulting oxidative stress produced in the nucleus is a key component of the nickel carcinogenic mechanism. The crosslinking of amino acids to DNA by nickel that does not involve direct participation of nickel in a ternary complex but nickel-induced oxidative stress will be discussed as well. The selective ability of particulate nickel compounds to silence the expression of genes located near heterochromatin and the effect of vitamin E on the genotoxicity and mutations induced by particulate and soluble nickel compounds will also be discussed. Particulate nickel compounds have been shown to produce more oxidative stress than water-soluble nickel compounds. In addition to nickel, the role of oxidative stress in chromate-induced genotoxicity will also be discussed with particular attention directed to the effects of vitamin E on mutations and chromosomal aberrations inducedby chromate.

  17. Large Scale Evaluation fo Nickel Aluminide Rolls

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-01

    This completed project was a joint effort between Oak Ridge National Laboratory and Bethlehem Steel (now Mittal Steel) to demonstrate the effectiveness of using nickel aluminide intermetallic alloy rolls as part of an updated, energy-efficient, commercial annealing furnace system.

  18. Zirconium modified nickel-copper alloy

    Science.gov (United States)

    Whittenberger, J. D. (Inventor)

    1977-01-01

    An improved material for use in a catalytic reactor which reduces nitrogen oxide from internal combustion engines is in the form of a zirconium-modified, precipitation-strengthened nickel-copper alloy. This material has a nominal composition of Ni-30 Cu-0.2 Zr and is characterized by improved high temperature mechanical properties.

  19. Nickel Complexes of Thiosemicarbazone Derivatives of Lawsone

    OpenAIRE

    Sanjay Gaikwad

    2013-01-01

    Thiosemicarbazone derivative at 1 position of the Lawsone ( 2-hydroxy-1,4-naphthalenedione ) i.e. 1-TSCND is an important derivative, Which possesses a powerful chelating ability, appreciable analytical utility and significant biological activity[1]. Its Nickel (II) complex is newly reported here

  20. Diffusion brazing nickel-plated stainless steel

    Science.gov (United States)

    Beuyukian, C. S.; Mitchell, M. J.

    1976-01-01

    To bond parts, sandwich assembly is made up of aluminum core, aluminum face sheet with brazing alloy interface, and nickel plated stainless steel part. Sandwich is placed between bottom and top glide sheet that is placed in stainless steel retort where assembly is bonded at 580 C.

  1. Nickel hydroxide modified electrodes for urea determination

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Dall´Antonia

    2007-03-01

    Full Text Available Nickel hydroxide films were prepared by electrodeposition from a solution Ni(NO32 0,05 mol L ?¹ on ITO electrodes (Tin oxide doped with Indium on PET-like plastic film, applying a current of - 0,1 A cm ?² during different time intervals between 1800 and 7200 s. The electrochemical behavior of the nickel hydroxide electrode was investigated through a cyclic voltammogram, in NaOH 1,0 mol L ?¹, where it was observed two peaks in the profile in 0,410 and 0,280 V, corresponding to redox couple Ni(II/Ni(III. A sensor for urea presenting a satisfactory answer can be obtained when, after the deposit of the film of Ni(OH2 on the electrode of nickel, it is immersed in a solution of NaOH 1,0 mol L ?¹ and applying a potential of + 0,435 V, where the maximum of the anodic current occurs in the cyclic voltammogram. Analyzing the results it can be observed that, for a range of analite concentration between 5 to 50 m mol L ?¹, the behavior is linear and the sensibility found was of 20,3 mA cm?² (mol L?¹?¹, presenting reproducibility confirming the nickel hydroxide electrodes utilization for the determination of urea.

  2. Surface magnetism in iron, cobalt, and nickel

    DEFF Research Database (Denmark)

    Alde´n, M.; Mirbt, S.; Skriver, Hans Lomholt

    1992-01-01

    We have calculated magnetic moments, work functions, and surface energies for several of the most closely packed surfaces of iron, cobalt, and nickel by means of a spin-polarized Green’s-function technique based on the linear muffin-tin orbitals method within the tight-binding and atomic sphere...

  3. Important Parameters and Applications for Nickel Electroforming

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Benzon, Michael Eis; Rasmussen, J.P.

    1996-01-01

    Electroforming is versatile process that is being used more and more, although the basic idea is almost a hundred years old. This paper will concentrate on the important mechanical properties and electrolyte parameters of nickel electroforming. Electrolyte parameters such as current density, pH...

  4. Multiple use of waste catalysts with and without regeneration for waste polymer cracking.

    Science.gov (United States)

    Salmiaton, A; Garforth, A A

    2011-06-01

    Waste plastics contain a substantial number of valuable chemicals. The wastes from post-consumer as well as from industrial production can be recycled to valuable chemical feedstock, which can be used in refineries and/or petrochemical industries. This chemical recycling process is an ideal approach in recycling the waste for a better environment. Polymer cracking using a laboratory fluidized bed reactor concentrated on the used highly contaminated catalyst, E-Cat 2. Even though E-Cat 2 had low activity due to fewer acid sites, the products yielded were similar with amorphous ASA and were far better than thermal cracking. The high levels of heavy metals, namely nickel and vanadium, deposited during their lifetime as an FCC catalyst, did not greatly affect on the catalyst activity. It was also shown that E-Cat 2 could be used with and without regeneration. Although there was more deactivation when there was no regeneration step, the yield of gases (C(2)-C(7)) remained fairly constant. For the first time, these results indicate that "waste" FCC catalyst (E-Cat) is a good candidate for future feedstock recycling of polymer waste. The major benefits of using E-Cat are a low market price, the ability to tolerate reuse and regeneration capacity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Deactivating Carbon Formation on a Ni/Al2O3 Catalyst under Methanation Conditions

    DEFF Research Database (Denmark)

    Olesen, Sine Ellemann; Andersson, Klas J.; Damsgaard, Christian Danvad

    2017-01-01

    The carbon formation causing deactivation during CO methanation was studied for a Ni/Al2O3 catalyst. Sulfur-free methanation at low temperature (573 K) for various lengths of time was followed by temperature-programmed hydrogenation (TPH) providing information on carbon types involved in the deac......The carbon formation causing deactivation during CO methanation was studied for a Ni/Al2O3 catalyst. Sulfur-free methanation at low temperature (573 K) for various lengths of time was followed by temperature-programmed hydrogenation (TPH) providing information on carbon types involved...... in the deactivation of the catalyst.Three main carbon hydrogenation peaks were evident from TPHs following methanation: ∼460, ∼650, and ∼775 K. It is suggested that the ∼460 K TPH peak was composed of two peaks: a surface carbide peak at 445–460 K, and a peak due to carbon dissolved into the nickel at 485 K based...... on CO and CH4 adsorption measurements and XRD analysis. The 650 and 775 K temperature peaks are assigned to polymerized carbon structures and the ∼775K peak was found to be the primary cause of deactivation as judged by a linear correlation between its amount and the degree of catalyst deactivation...

  6. Epicutaneous exposure to nickel induces nickel allergy in mice via a MyD88-dependent and interleukin-1-dependent pathway

    DEFF Research Database (Denmark)

    Vennegaard, Marie T; Dyring-Andersen, Beatrice; Skov, Lone

    2014-01-01

    of nickel in the epidermis, and induces nickel allergy in mice. The allergic response to nickel following epicutaneous exposure is MyD88-dependent and interleukin (IL)-1 receptor-dependent, but independent of toll-like receptor (TLR)-4. CONCLUSION: This new model for nickel allergy that reflects...... epicutaneous exposure to nickel in humans shows that nickel allergy is dependent on MyD88 and IL-1 receptor signalling, but independent of TLR4....

  7. Reduction of CO2 by nickel (II) macrocycle catalyst at HMDE

    Indian Academy of Sciences (India)

    Unknown

    it an inefficient consumer of energy and restricting the possibility of practical application. To diminish the ... to its geometry, i.e. because square planar structure provides the axial site free for the approach and interaction of ... and a voltage scan generator with a graphtec XY-recorder WX 2300, using a three- electrode system ...

  8. On the preparation and characterisation of MCM-41 supported heterogeneous nickel and molybdenum catalysts

    NARCIS (Netherlands)

    Lensveld, Dennis

    2003-01-01

    MCM-41 is an ordered mesoporous material, displaying a honeycomb-like structure of uniform mesopores (3 nm in diameter) running through a matrix of amorphous silica. Because of the high porosity (pore volume » 1.0 ml g-1) and concomitant large surface area (approximately 1,000 m2 g-1) MCM-41 is in

  9. SYNTHESIS AND CHARACTERIZATION OF NANOCOMPOSITES OF OXIDES AND METALLIC NICKEL FOR USE AS CARBON NANOTUBES CATALYST

    OpenAIRE

    RONALD BEYNER MEJIA SANCHEZ

    2014-01-01

    Foram desenvolvidos nanocompósitos de óxidos dopados com níquel metálico pelo processo Sol-Gel modificado pelo uso do PVA (Álcool Polivinílico) na função de matriz de crescimento dos nanocompósitos. Os precursores dos óxidos foram os nitratos de seus próprios metais. Foram sintetizados três tipos de nanocompósitos óxido de magnésio, óxido de alumínio e óxido de zinco. O trabalho envolveu quatro etapas principais: levantamento bibliográfico, desenvolvimento e caracterização dos nanocompósitos ...

  10. Plasma-assisted catalytic dry reforming of methane: Highly catalytic performance of nickel ferrite nanoparticles embedded in silica

    Science.gov (United States)

    Zheng, Xiaogang; Tan, Shiyu; Dong, Lichun; Li, Shaobo; Chen, Hongmei

    2015-01-01

    Spinel nickel ferrite nanoparticles (NiFe2O4 NPs) embedded in silica (NiFe2O4#SiO2) was prepared to enhance the reaction performance of the dry reforming of methane in a coaxial dielectric barrier discharge reactor. NiFe2O4 NPs of around 10 nm were effectively embedded in porous SiO2 NPs (∼100 nm in diameter). Compared to the supported Ni-based catalysts (Ni/γ-Al2O3, Ni-Fe/γ-Al2O3, Ni-Fe/SiO2, and NiFe2O4), the NiFe2O4#SiO2 catalyst placed at the discharge zone exhibited excellent catalytic performance and high resistance to carbon formation during dry reforming under ambient conditions without the involvement of extra heat. The synergetic effect between the non-thermal plasma and the NiFe2O4#SiO2 catalyst favored the conversion of CH4 and CO2 into syngas. The results indicated that the special structure of the as-synthesized NiFe2O4#SiO2 catalyst was capable of restraining the aggregation of Ni-Fe alloy and suppressing the carbon formation in the reforming process.

  11. Catalyst containing oxygen transport membrane

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Jonathan A.; Wilson, Jamie R.; Christie, Gervase Maxwell; Petigny, Nathalie; Sarantopoulos, Christos

    2017-02-07

    A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a microstructure exhibiting substantially uniform pore size distribution as a result of using PMMA pore forming materials or a bi-modal particle size distribution of the porous support layer materials. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

  12. Catalyst containing oxygen transport membrane

    Science.gov (United States)

    Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

    2012-12-04

    A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

  13. Heterogenization of alkene epoxidation catalysts

    Directory of Open Access Journals (Sweden)

    Buffon Regina

    2003-01-01

    Full Text Available This account describes our efforts to heterogenize epoxidation catalysts. Anchored and sol-gel entrapped molybdenum were shown to be very selective, but had a strongly reduced activity. On the other hand, molybdenum silicates were very active and stable as long as no diols were present in the reaction mixture. Heterogenized rhenium catalysts were less active but allowed the use of anhydrous hydrogen peroxide as oxidant. However, the high cost and difficult regeneration prevents the industrial use of these catalysts. During these investigations, we found that alumina alone is active in the epoxidation with anhydrous hydrogen peroxide, giving good conversions to epoxides with high selectivity. More research is needed in order to clarify the nature of the hydroxyl groups responsible for its catalytic activity and thus to produce an appropriate material which would allow the obtention of epoxides with high selectivity under industrial conditions.

  14. Rhenium Nanochemistry for Catalyst Preparation

    Directory of Open Access Journals (Sweden)

    Vadim G. Kessler

    2012-08-01

    Full Text Available The review presents synthetic approaches to modern rhenium-based catalysts. Creation of an active center is considered as a process of obtaining a nanoparticle or a molecule, immobilized within a matrix of the substrate. Selective chemical routes to preparation of particles of rhenium alloys, rhenium oxides and the molecules of alkyltrioxorhenium, and their insertion into porous structure of zeolites, ordered mesoporous MCM matrices, anodic mesoporous alumina, and porous transition metal oxides are considered. Structure-property relationships are traced for these catalysts in relation to such processes as alkylation and isomerization, olefin metathesis, selective oxidation of olefins, methanol to formaldehyde conversion, etc.

  15. Bismuth catalysts in aqueous media.

    Science.gov (United States)

    Kobayashi, Shū; Ueno, Masaharu; Kitanosono, Taku

    2012-01-01

    Several bismuth-catalyzed synthetic reactions, which proceed well in aqueous media, are discussed. Due to increasing demand of water as a solvent in organic synthesis, catalysts that can be used in aqueous media are becoming more and more important. Although bismuth Lewis acids are not very stable in water, it has been revealed that they can be stabilized by basic ligands. Chiral amine and related basic ligands combined with bismuth Lewis acids are particularly useful in asymmetric catalysis in aqueous media. On the other hand, bismuth hydroxide is stable and works as an efficient catalyst for carbon-carbon bond-forming reactions in water.

  16. Quick Guide to Flash Catalyst

    CERN Document Server

    Elmansy, Rafiq

    2011-01-01

    How do you transform user interface designs created in Photoshop or Illustrator into interactive web pages? It's easier than you think. This guide shows you how to use Adobe Flash Catalyst to create interactive UIs and website wireframes for Rich Internet Applications-without writing a single line of code. Ideal for web designers, this book introduces Flash Catalyst basics with detailed step-by-step instructions and screenshots that illustrate every part of the process. You'll learn hands-on how to turn your static design or artwork into working user interfaces that can be implemented in Fla

  17. Novel Fischer-Tropsch catalysts. [DOE patent

    Science.gov (United States)

    Vollhardt, K.P.C.; Perkins, P.

    Novel compounds are described which are used as improved Fischer-Tropsch catalysts particularly for the conversion of CO + H/sub 2/ to gaseous and liquid hydrocarbons at milder conditions than with prior catalysts.

  18. Automotive Catalyst State Diagnosis Using Microwaves

    National Research Council Canada - National Science Library

    Moos, Ralf; Fischerauer, Gerhard

    2015-01-01

    .... The soot or ash loading of Diesel particulate filters, the oxygen loading degree in three-way catalysts, the amount of stored ammonia in SCR catalysts, or the NOx loading degree in NOx storage...

  19. Catalyst for Decomposition of Nitrogen Oxides

    Science.gov (United States)

    Schryer, David R. (Inventor); Jordan, Jeffrey D. (Inventor); Akyurtlu, Ates (Inventor); Akyurtlu, Jale (Inventor)

    2015-01-01

    This invention relates generally to a platinized tin oxide-based catalyst. It relates particularly to an improved platinized tin oxide-based catalyst able to decompose nitric oxide to nitrogen and oxygen without the necessity of a reducing gas.

  20. Hydrogen Production via Glycerol Dry Reforming over La-Ni/Al2O3 Catalyst

    Directory of Open Access Journals (Sweden)

    Kah Weng Siew

    2013-12-01

    Full Text Available Glycerol (a bio-waste generated from biodiesel production has been touted as a promising bio-syngas precursor via reforming route. Previous studies have indicated that carbon deposition is the major performance-limiting factor for nickel (Ni catalyst during glycerol steam reforming. In the current paper, dry (CO2-reforming of glycerol, a new reforming route was carried out over alumina (Al2O3-supported non-promoted and lanthanum-promoted Ni catalysts. Both sets of catalysts were synthesized via wet co-impregnation procedure. The physicochemical characterization of the catalyst showed that the promoted catalyst possessed smaller metal crystallite size, hence higher metal dispersion compared to the virgin Ni/Al2O3 catalyst. This was also corroborated by the surface images captured by the FESEM analysis. In addition, BET surface area measurement gave 92.05m²/g for non-promoted Ni catalyst whilst promoted catalysts showed an average of 1 to 6% improvement depending on the La loading. Reaction studies at 873 K showed that glycerol dry reforming successfully produced H2 with glycerol conversion and H2 yield that peaked at 9.7% and 25% respectively over 2wt% La content. The optimum catalytic performance by 2%La-Ni/Al2O3 can be attributed to the larger BET surface area and smaller crystallite size that ensured accessibility of active catalytic sites.  © 2013 BCREC UNDIP. All rights reservedReceived: 12nd May 2013; Revised: 7th October 2013; Accepted: 16th October 2013[How to Cite: Siew, K.W., Lee, H.C., Gimbun, J., Cheng, C.K. (2013. Hydrogen Production via Glycerol Dry Reforming over La-Ni/Al2O3 Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (2: 160-166. (doi:10.9767/bcrec.8.2.4874.160-166][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.2.4874.160-166