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Sample records for ru pd ir

  1. Synthesis, crystal structure, and electronic properties of high-pressure PdF2-type oxides MO2 (M = Ru, Rh, Os, Ir, Pt).

    Science.gov (United States)

    Shirako, Yuichi; Wang, Xia; Tsujimoto, Yoshihiro; Tanaka, Kie; Guo, Yanfeng; Matsushita, Yoshitaka; Nemoto, Yoshihiro; Katsuya, Yoshio; Shi, Youguo; Mori, Daisuke; Kojitani, Hiroshi; Yamaura, Kazunari; Inaguma, Yoshiyuki; Akaogi, Masaki

    2014-11-03

    The polycrystalline MO2's (HP-PdF2-type MO2, M = Rh, Os, Pt) with high-pressure PdF2 compounds were successfully synthesized under high-pressure conditions for the first time, to the best of our knowledge. The crystal structures and electromagnetic properties were studied. Previously unreported electronic properties of the polycrystalline HP-PdF2-type RuO2 and IrO2 were also studied. The refined structures clearly indicated that all compounds crystallized into the HP-PdF2-type structure, M(4+)O(2-)2, rather than the pyrite-type structure, M(n+)(O2)(n-) (n superconductivity nor a magnetic transition was detected down to a temperature of 2 K, unlike the case of 3d transition metal chalcogenide pyrites.

  2. Coexistence of magnetic order, heavy fermion and intermediate valence behaviour in Ce{sub 7}X{sub 3} (X=Ni, Ru, Pd, Pt, Ir and Rh)

    Energy Technology Data Exchange (ETDEWEB)

    Trovarelli, O. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche; Sereni, J.G. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche; Schmerber, G. [IPCMS-GEMM, 23 rue du Loess, 67037 Strasbourg (France); Kappler, J.P. [IPCMS-GEMM, 23 rue du Loess, 67037 Strasbourg (France)

    1995-02-01

    Low temperature specific heat, AC magnetic susceptibility and magnetization measurements were performed on the Ce{sub 7}X{sub 3} compounds (X=Ni, Ru, Rh, Pd, Ir and Pt). They exhibit coexistence of magnetic order (MO), heavy fermion (HF) and intermediate valence (IV) behaviour and the results are interpreted in terms of the three Ce sublattices (1Ce{sub I}, 3Ce{sub II} and 3Ce{sub III}) present in the Th{sub 7}Fe{sub 3}-type structure. From entropic considerations it is found that sublattice Ce{sub III} presents an IV behaviour in all these compounds and Ce{sub II} show MO or have a HF behaviour depending on the Ce-ligand electronic structure. The Ce{sub I} atoms (more than 6A distant from each other) exhibit MO only when the Ce{sub II} sublattice provides a high density of electronic states. ((orig.)).

  3. Screening of electrocatalysts for direct ammonia fuel cell: Ammonia oxidation on PtMe (Me: Ir, Rh, Pd, Ru) and preferentially oriented Pt(1 0 0) nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Vidal-Iglesias, F.J.; Solla-Gullon, J.; Montiel, V.; Feliu, J.M.; Aldaz, A. [Instituto de Electroquimica, Universidad de Alicante, Apartado 99, 03080 Alicante (Spain)

    2007-09-27

    Ammonia has attracted attention as a possible fuel for direct fuel cells since it is easy to handle and to transport as liquid or as concentrated aqueous solution. However, on noble metal electrodes ammonia oxidation is a sluggish reaction and the electrocatalyst needs to be improved for developing efficient ammonia fuel cells. In this work, ammonia electrooxidation reaction on 3-4-nm bimetallic PtMe (Ir, Rh, Pd, Ru) and on preferentially oriented Pt(1 0 0) nanoparticles is reported. PtMe nanoparticles have been prepared by using water-in-oil microemulsions to obtain a narrow size distribution whereas preferentially oriented Pt nanoparticles have been prepared through colloidal routes. Among all the bimetallic samples tested, only Pt{sub 75}Ir{sub 25} and Pt{sub 75}Rh{sub 25} nanoparticles show, at the low potential range, an enhancement of the oxidation density current with respect to the behaviour found for pure platinum nanoparticles prepared by the same method. In addition, two Pt(1 0 0) preferentially oriented nanoparticles of different particle size (4 and 9 nm) have been also studied. These oriented nanoparticles show higher current densities than polycrystalline Pt nanoparticles due to the sensitivity of ammonia oxidation toward the presence of surface sites with square symmetry. The reactivity of the different 4-nm nanoparticles parallels well with that expected from bulk PtMe alloys and Pt single crystal electrodes. (author)

  4. RuS2-OsS2-IrS2的类质同象矿物系列和PdS-PtS矿物系列

    Institute of Scientific and Technical Information of China (English)

    任英忱; 邓禹仁

    1973-01-01

    Based on the results from, studies of minerals belonging to these two systems ,and by reference to pertinent data available, the authors are of thc following opinious: The system RiS2-Os4S2-IrS2 is a complete isomorphous series. Unit cell parameters and physical properties of the mincrals vary with chemical compositions in a systematic manner. PdS-FtS is a limited isomorphous series. Two groups, cooperite [including(Pd0-0.113Pt1-0.387)1.00S1.00] platinum.bearing palladium sulfides [chemical formula(Pd0.86-0.39Pt0.14-0.61)1.00S1.00] can be distinguished within this system. Beeause of differences in crystal structures between the two groups, which is also responsible for the significant differences in physical properties of these minerals, the system PdS-PtS is discontinuous, but each group itself constitutes a complete isomorphous series.

  5. Partial phase diagram of Pd-Ag-Ru-Gd quaternary system

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    On the basis of the Ag-Pd-Gd, Ag-Ru-Gd and Pd-Ru-Gd ternary systems, the partial phase diagram of Pd-Ag-Ru-Gd(Gd<25% atom fraction) quaternary system has been studied by means of X-ray diffraction analysis, differential thermal analysis, electron probe microanalysis and optical microscopy.The 700℃ isothermal sections of the Ag-Pd-5Ru-Gd, Ag-Pd-20Ru-Gd and Ag-Pd-50Ru-Gd (Gd≤25%atom fraction) phase diagrams were determined respectively. And the 700℃ isothermal section of the PdAg-Ru-Gd (Gd≤25% atom fraction) quaternary system phase diagram was finally irferred. The section consists of four single-phase regions: solid solution Pd(Ag), (Ru), Pd3Gd and Ag51 Gd14; five two-phase regions: Pd(Ag) + (Ru), Pd(Ag) + Ag51 Gd14 , (Ru) + Ag51 Gd14 , Pd(Ag) + Pd3Gd and (Ru) +Pd3Gd; three three-phase regions: Pd(Ag) + Pd3Gd+ (Ru), Pd(Ag) + Ag51Gd14 + (Ru) and (Ru) +Ag51Gd14 + Pd3Gd; one four-phase region Pd(Ag) + (Ru) + Ag51Gd14 + Pd3Gd. No new quaternary intermetallic phase is found.

  6. Ordered Porous Pd Octahedra Covered with Monolayer Ru Atoms.

    Science.gov (United States)

    Ge, Jingjie; He, Dongsheng; Bai, Lei; You, Rui; Lu, Haiyuan; Lin, Yue; Tan, Chaoliang; Kang, Yan-Biao; Xiao, Bin; Wu, Yuen; Deng, Zhaoxiang; Huang, Weixin; Zhang, Hua; Hong, Xun; Li, Yadong

    2015-11-25

    Monolayer Ru atoms covered highly ordered porous Pd octahedra have been synthesized via the underpotential deposition and thermodynamic control. Shape evolution from concave nanocube to octahedron with six hollow cavities was observed. Using aberration-corrected high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy, we provide quantitative evidence to prove that only a monolayer of Ru atoms was deposited on the surface of porous Pd octahedra. The as-prepared monolayer Ru atoms covered Pd nanostructures exhibited excellent catalytic property in terms of semihydrogenation of alkynes.

  7. Submonolayered Ru Deposited on Ultrathin Pd Nanosheets used for Enhanced Catalytic Applications.

    Science.gov (United States)

    Zhang, Zhicheng; Liu, Ye; Chen, Bo; Gong, Yue; Gu, Lin; Fan, Zhanxi; Yang, Nailiang; Lai, Zhuangchai; Chen, Ye; Wang, Jie; Huang, Ying; Sindoro, Melinda; Niu, Wenxin; Li, Bing; Zong, Yun; Yang, Yanhui; Huang, Xiao; Huo, Fengwei; Huang, Wei; Zhang, Hua

    2016-12-01

    Ultrathin Pd nanosheets (NSs) coated with submonolayered Ru, referred to as Pd@Ru NSs, are synthesized via a seed-mediated growth method. The underpotential deposition can be the driving force for the formation of Pd@Ru NSs. The Pd@Ru NSs exhibit superior catalytic properties in the reduction of 4-nitrophenol and the semihydrogenation of 1-octyne, compared to the pure Pd NSs and Ru NSs.

  8. Ternary rare-earth aluminium intermetallics RE10TAl3 (RE = Y, Ho, Tm, Lu; T = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt) with an ordered anti-Co2Al5 structure.

    Science.gov (United States)

    Benndorf, Christopher; Eckert, Hellmut; Janka, Oliver

    2017-01-24

    Twenty new rare-earth metal rich intermetallic aluminium compounds, RE10TAl3 (RE = Y, Ho, Tm, Lu; T = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt), were synthesized by arc melting the elements. The compounds crystallize, in analogy to e.g. the respective Cd representatives, with a ternary ordered structure as anti-type to the hexagonal Co2Al5 type, with the space group P63/mmc. The three crystallographically independent rare-earth metal sites occupy the aluminium positions of the aristotype, while the transition metal and aluminium atoms are ordered on the two cobalt sites. Like other rare-earth rich compounds the RE10TX3 members also exhibit transition-metal-centred T@RE6 trigonal prisms as striking structural building units. The prepared compounds have been investigated by susceptibility measurements and (27)Al solid-state MAS-NMR measurements conducted on the Pauli-paramagnetic Y and Lu compounds. Some compounds show a certain amount of disorder as seen from the single crystal structure analysis and from signal broadening in the NMR investigations. By separating Knight shifts from second-order quadrupolar shifts via field dependent measurements, monotonic trends can be discerned regarding the effect of the T atom valence electron concentration and period number, as well as the effect of the closed 4f shell contributed in the Lu compounds. The results confirm that a comparison of Knight shifts within a series of isotypic compounds can reveal important electronic structure information in intermetallic systems.

  9. High-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles for phenol hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chao [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Yang, Xu [Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou (China); Yang, Hui; Huang, Peiyan; Song, Huiyu [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Liao, Shijun, E-mail: chsjliao@scut.edu.cn [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China)

    2014-10-01

    Graphical abstract: The addition of Ru could significantly improve the performance of the mesoporous silica nanoparticles supported PdRu/MSN catalyst, which showed over 5 times higher mass activity than the mono-Pd/MSN towards the liquid-phase hydrogenation of phenol. The improved dispersion and the electronic interaction contributed to the enhanced catalytic activity for the catalyst towards phenol hydrogenation. - Highlights: • PdRu bimetal catalyst supported on mesoporous silica nanoparticles was prepared. • The average sizeof PdRu alloy is smaller than that of mono-Pd. • The addition of Ru to Pd modulates the electronic properties between Pd and Ru. • PdRu/MSN catalyst shows superior activity on phenol hydrogenation than Pd/MSN. • PdRu/MSN catalyst shows good selectivity for cyclohexanol to some extent. - Abstract: A high-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles (MSN), PdRu/MSN, was prepared by a facile impregnation–hydrogen reduction method. It was found that PdRu/MSN showed 5 times higher activity than that of Pd/MSN towards the liquid-phase hydrogenation of phenol. The catalysts were characterized comprehensively by multiple techniques, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and hydrogen temperature program reduction (TPR). It was revealed that adding Ru could effectively improve the Pd dispersion and promote the electronic interaction between the Pd and Ru, both of which contribute to enhancing the catalytic activity.

  10. Contribution à la cristallochimie des isotypes de ThCr 2Si 2 et CaBe 2Ge 2. I. Les systèmes La T2- xT' xGe 2 ( T, T' = Ru, Rh, Pd, Ir, Pt) et La 1- xCa xCa xIr 2Ge 2: Distribution des éléments de transition dans le type CaBe 2Ge 2

    Science.gov (United States)

    Venturini, G.; Malaman, B.; Roques, B.

    1989-03-01

    There are several singularities in the systems investigated. Although the three germanides La T2Ge 2( T = Ru, Rh, Pd) are isostructural with ThCr 2Si 2, a complete solid solution occurs only between LaRu 2Ge 2 and LaRh 2Ge 2; in the system LaRh 2Ge 2LaPd 2Ge 2, there is a range of CaBe 2Ge 2-type solid solutions. The lattice constants of the ThCr 2Si 2-type compounds vary curiously according to the valence electron concentration (VEC). The CaBe 2Ge 2-type germanides are confined in a narrow range of VEC. The new compound CaIr 2Ge 2 is then of the ThCr 2Si 2-type while LaIr 2Ge 2 is of the CaBe 2Ge 2-type. In the latter structural type, the square pyramids of Ge atoms are favorite sites for Ir or Pt atoms. These results are discussed.

  11. RuPd, RuCo, PdCo and RuPdCo materials as candidates for cathode catalyzers in PEM fuel cells; Materiales RuPd, RuCo, PdCo y RuPdCo como candidatos a catalizadores catodicos en celdas de combustible tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Leyva Noyola, Fatima; Solorza Feria, Omar [Centro de Investigacion y Estudios Superiores del IPN, Mexico, D.F. (Mexico)]. E-mail: fleyva@cinvestav.mx

    2009-09-15

    This work reports on the catalytic activity of RuPd, RuCo, PdCo and RuPdCo material for oxygen reduction reaction (ORR). These materials were synthesized using chemical reduction with NaBH{sub 4} as a reducing agent in THF, in ambient temperature and pressure conditions. The evaluation of the catalytic activity was done using cyclic voltamperometry (CV) and rotary disc electrode (RDE) in H{sub 2}SO{sub 4} 0.5 M. The kinetic results showed that the electrochemical reaction involves 4 electrons and the transfer of the first electron is the determinant stage. The values of {alpha}, i0 and the Tafel slope were very similar for the four materials studied, around 0.4, 5x10{sup -6} mA cm{sup -2} and 60 mV dec-1, respectively. Although these values are less than those reported for nanostructured platinum, they are better than those reported for other materials such as pure Pd, which enables them to be considered as cathode catalysts for a proton exchange membrane fuel cell. [Spanish] En este trabajo se reporta la actividad catalitica de los materiales RuPd, RuCo, PdCo y RuPdCo para la reaccion de reduccion de oxigeno (RRO). Estos materiales fueron sintetizados por el metodo de reduccion quimica, usando NaBH{sub 4} como agente reductor en THF, en condiciones de temperatura y presion ambiental. La evaluacion de la actividad catalitica fue realizada usando Voltamperometria Ciclica (VC) y Electrodo Disco Rotatorio (EDR) en H{sub 2}SO{sub 4} 0.5 M. Los resultados cineticos mostraron que la reaccion electroquimica procede por la via de 4 electrones y la etapa determinante es la transferencia del primer electron. Los valores de {alpha}, i0 y pendiente de Tafel fueron muy similares para los 4 materiales estudiados, siendo estos de alrededor de 0.4, 5x10{sup -6} mA cm{sup -2} y 60 mV dec{sup -1}, respectivamente. Sin embargo, aun cuando estos valores son menores que los reportados para platino nanoestructurado, son mejores que los reportados para otros materiales como el Pd puro

  12. Carbon supported Pd-Sn and Pd-Ru-Sn nanocatalysts for ethanol electro-oxidation in alkaline medium

    CSIR Research Space (South Africa)

    Modibedi, RM

    2011-04-01

    Full Text Available the coverage of the adsorbed ethoxy (CH3COads) species on the nanocatalyst surface, thus yielding an increase in current density. Pd-Sn/C displayed better electrocatalytic activity and stability towards poisoning than Pd-Ru-Sn/C and Pt-Ru/C (E-TEK Inc...

  13. High-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles for phenol hydrogenation

    Science.gov (United States)

    Huang, Chao; Yang, Xu; Yang, Hui; Huang, Peiyan; Song, Huiyu; Liao, Shijun

    2014-10-01

    A high-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles (MSN), PdRu/MSN, was prepared by a facile impregnation-hydrogen reduction method. It was found that PdRu/MSN showed 5 times higher activity than that of Pd/MSN towards the liquid-phase hydrogenation of phenol. The catalysts were characterized comprehensively by multiple techniques, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and hydrogen temperature program reduction (TPR). It was revealed that adding Ru could effectively improve the Pd dispersion and promote the electronic interaction between the Pd and Ru, both of which contribute to enhancing the catalytic activity.

  14. Interference removals on Pd, Ru and Au with ICP-QQQ-MS in PGE RM

    Science.gov (United States)

    Nadeem Hussain Bokhari, Syed; Meisel, Thomas; Walkner, Christoph

    2015-04-01

    Gold and platinum group elements (PGE) are essential industrial precious metals with high world demand due to their unique properties. Struggle for natural exploration of PGE is on great pace and recycling from industrial wastes, electronics and catalytic convertor is on the rise for PGE supply chain. Along with these developments it is becoming more challenging for analytical chemists to determine gold and PGE out of complex matrix which causes severe interferences. The current state of art is online analysis coupled with chromatographic separation of interferences. The ICP-QQQ-MS Agilent 8800 has the capability of using multi tunes and mass shifts. We aim to remove interferences on Pd+ (for direct and isotope dilution analysis) Au+ and Ru+ in lieu of chemical separations. YO+, SrOH+, ZnAr+, NiAr+, ZrO+, CuAr+, MoO+ , Ru+and Cd+ are expected interferences on Pd+ while Au+ is interfered by TaO+, HfOH+, GdAr+ and 102Ru+ ,104Ru+ by 102Pd+ ,104Pd+ etc. Initial test were performed on pure solutions of 1mg/l (interfering elements): 1 ng/l (Pd, Ru & Au) respectively. The outcomes of initial tests were applied on PGE reference material (RM) WMG-1 and SARM-7 (digested with Na2O2 sintering). The results obtained show that YO+, SrOH+ interfere (104Pd,105Pd), 104 Ru+ on (104Pd), ZnAr+ has slight interference on (104Pd and106Pd), ZrO+, NiAr+, CuAr+ interferences are negligible, MoO+ has severe interference on (108Pd, 110Pd) and that Cd+ has severe isobaric interference on (106Pd,108Pd, 110Pd). These interference have been removed by formation of Pd(NH3)3+complex. The TaO+, HfOH+ and GdAr+ interferences on Au+ are best removed by formation of Au(NH3)+ and Au(NH3)2+ complexes. 102Pd+,104Pd+interference on 102Ru+ ,104Ru+ can be removed by formation of Ru(NH3)4+ and RuO+ compounds. The results obtained comply with certified values of RM. The developed method is being tested on low concentration PGE reference materials. References: Sugiyama, N. " Removal of complex spectral

  15. Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts for the alkaline direct ethanol fuel cell (DEFC)

    CSIR Research Space (South Africa)

    Mathe, MK

    2011-08-01

    Full Text Available Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts were prepared by the chemical reduction method, using sodium borohydride and ethylene glycol mixture as the reducing agent. The catalytic activity towards ethanol electro-oxidation in alkaline medium...

  16. Methane Direct Conversion on Mo/ZSM-5 Catalysts Modified by Pd and Ru

    Institute of Scientific and Technical Information of China (English)

    Priscila Dias Sily; Fabio Bellot Noronha; Fabio Barboza Passos

    2006-01-01

    The effect of addition of Ru and Pd to Mo/HZSM-5 catalysts used in the dehydroaromatization of methane was investigated. Catalytic tests and temperature-programmed oxidation results showed that Pd-based catalysts were more selective to naphthalene and suffered strong deactivation. The presence of Ru improved the activity and stability, with a decrease in the carbonaceous deposit probably because of a mechanism of protection of the Mo2C surface.

  17. Photocatalytic Reduction of Carbon Dioxide with Modify Pd, Ru on TiO2 Surface

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Photocatalytic reduction of CO2 to organic compounds was reduction in semiconductor suspension system under simulated solar in laboratory. TiO2 load catalysts were prepared in different ways, and they were used in photocatalytic reduction of CO2 . Experimental results show that the photocatalytic activity can be improve by dressing Pd, Ru on TiO2 Surface and is obvious different when catalysts were prepared in different ways. The photocatalytic mechanism of dressing Pd on TiO2 Surface; dressing Pd and Ru on TiO2 Surface were also discussed in this paper.

  18. The Mechanism of Direct Formic Acid Fuel Cell Using Pd, Pt and Pt-Ru

    Science.gov (United States)

    Kamiya, Nobuyuki; Liu, Yan; Mitsushima, Shigenori; Ota, Ken-Ichiro; Tsutsumi, Yasuyuki; Ogawa, Naoya; Kon, Norihiro; Eguchi, Mika

    The electro-oxidation of formic acid, 2-propanol and methanol on Pd black, Pd/C, Pt-Ru/C and Pt/C has been investigated to clear the reaction mechanism. It was suggested that the formic acid is dehydrogenated on Pd surface and the hydrogen is occluded in the Pd lattice. Thus obtained hydrogen acts like pure hydrogen supplied from the outside and the cell performance of the direct formic acid fuel cell showed as high as that of a hydrogen-oxygen fuel cell. 2-propanol did not show such dehydrogenation reaction on Pd catalyst. Platinum and Pt-Ru accelerated the oxidation of C-OH of 2-propanol and methanol. Slow scan voltammogram (SSV) and chronoamperometry measurements showed that the activity of formic acid oxidation increased in the following order: Pd black > Pd 30wt.%/C > Pt50wt.%/C > 27wt.%Pt-13wt.%Ru/C. A large oxidation current for formic acid was found at a low overpotential on the palladium electrocatalysts. These results indicate that formic acid is mainly oxidized through a dehydrogenation reaction. For the oxidation of 2-propanol and methanol, palladium was not effective, and 27wt.%Pt-13wt.%Ru/C showed the best oxidation activity.

  19. The Effect of PtRuIr Nanoparticle Crystallinity in Electrocatalytic Methanol Oxidation

    Directory of Open Access Journals (Sweden)

    Vladimir Linkov

    2013-04-01

    Full Text Available Two structural forms of a ternary alloy PtRuIr/C catalyst, one amorphous and one highly crystalline, were synthesized and compared to determine the effect of their respective structures on their activity and stability as anodic catalysts in methanol oxidation. Characterization techniques included TEM, XRD, and EDX. Electrochemical analysis using a glassy carbon disk electrode for cyclic voltammogram and chronoamperometry were tested in a solution of 0.5 mol L−1 CH3OH and 0.5 mol L−1 H2SO4. Amorphous PtRuIr/C catalyst was found to have a larger electrochemical surface area, while the crystalline PtRuIr/C catalyst had both a higher activity in methanol oxidation and increased CO poisoning rate. Crystallinity of the active alloy nanoparticles has a big impact on both methanol oxidation activity and in the CO poisoning rate.

  20. Evolution of magnetism in Ru doped Na2IrO3

    Science.gov (United States)

    Mehlawat, Kavita; Singh, Yogesh

    2016-05-01

    We synthesized Ru doped single crystalline samples of the honeycomb iridate material Na2IrO3 and studied their magnetic properties using AC and DC magnetic susceptibility. The parent compound Na2IrO3 is a spin orbit driven Mott insulator with long range order below TN = 15 K. We find that even smallest substitution of Ru changes the antiferromagnetic long range order state to a spin glass like state indicating the fragile nature of magnetism in Na2IrO3. We track the freezing temperature Tg as a function of Ru concentration and the shift of Tg with frequency f of the ac modulation in AC susceptibility which is found to be very different from canonical spin-glasses like Cu-Mn.

  1. Conversion of isopropyl alcohol over Ru and Pd loaded N-doped carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Anas Benyounes; Mohamed Kacimi; Mahfoud Ziyad; Philippe Serp

    2014-01-01

    Ru and Pd (2 wt%) loaded on pure and on N-doped carbon nanotubes (N-CNTs) were prepared and tested using the isopropyl alcohol decomposition reaction as probe reaction. The presence of nitro-gen functionalities (pyridinic, pyrrolic, and quaternary nitrogen) on the nitrogen doped support induced a higher metal dispersion:Pd/N-CNT (1.8 nm)<Pd/CNT (4.9 nm), and Ru/N-CNT (2.4 nm)<Ru/CNT (3.0 nm). The catalytic activity of the supports was determined first. Isopropyl alcohol conversion produces acetone on CNTs while on N-CNTs it led to both dehydration and dehydro-genation products. At 210 °C and in the presence of air, the isopropyl alcohol conversion was higher on the N-CNTs (25%) than on the CNTs (11%). The Pd loaded catalysts were more active and more selective than the Ru ones. At 115 °C, the Pd catalysts were 100%selective towards acetone for a conversion of 100%, whereas the Ru catalysts led to dehydration and dehydrogenation products. The nitrogen doping induced the appearance of redox properties when oxygen is present in the reaction mixture.

  2. The effect of peripheral bipyridine ligands on the photocatalytic hydrogen production activity of Ru/Pd catalysts

    NARCIS (Netherlands)

    Bindra, Gurmeet Singh; Schulz, Martin; Paul, Avishek; Soman, Suraj; Groarke, Robert; Inglis, Jane; Pryce, Mary T.; Browne, Wesley R.; Rau, Sven; Maclean, Brian J.; Vos, Johannes G.

    2011-01-01

    A pyrazine bridged ruthenium/palladium bimetallic photocatalyst with peripheral 4,4'-dicarboxyethyl-2,2'-bipyridine ligands, EtOOC-RuPd, is reported, together with its 2,2'-bipyridine analogue. Upon irradiation with visible light, EtOOC-RuPd catalyses the production of hydrogen gas whereas the compl

  3. New Phase Regions of Ir-Ru-Ti System with Eutectic-Peritectic Transformation

    Science.gov (United States)

    Lutsyk, V.; Vorob'eva, V.

    2013-12-01

    Special surfaces, corresponding to phase transformation type changing, have been found and designed within six three-phase regions of the system Ti-Ir-Ru with a help of 3D computer model of its T-x-y diagram.

  4. Mixed-phase PdRu bimetallic structures with high activity and stability for formic acid electrooxidation.

    Science.gov (United States)

    Wu, Dongshuang; Zheng, Zhaoliang; Gao, Shuiying; Cao, Minna; Cao, Rong

    2012-06-14

    Aiming at investigating the effect of structure on electrocatalytic properties, Pd(50)Ru(50) nanoparticles (NPs) with three different structures were carefully designed in a one-pot polyol process for application in formic acid electrooxidation. The three structures are: (1) single-phase PdRu nanodendrites (denoted as PR-1), (2) a mixed-phase mixture of PdRu nanodendrites and monometallic Ru NPs (denoted as PR-2), and (3) a mixed-phase mixture of monometallic Pd and Ru NPs (denoted as PR-3). From PR-1 to PR-3, the structure was varied from single-phase to mixed-phase. The relative position of Ru was altered from completely Pd-connected (PR-1), to a mixture of Pd-connected and monometallic (PR-2), and completely monometallic (PR-3). All PdRu NPs outperform the commercial Pd/C. PR-2 exhibits the highest peak current density, but its stability is slightly lower than that of PR-3. When both the current density and the durability are taken into consideration, PR-2 is the best choice of catalyst for formic acid oxidation. It indicates that both the Pd-connected Ru NPs and monometallic Ru NPs in the mixed-phase PR-2 are essential to improve the electrocatalytic properties. Our study also illustrates that the electrochemical active surface area (ECSA) and hydrogen storage capacity of the as-prepared PdRu NPs are greatly enhanced after several hundred scans in formic acid, indicating the possibility for highly restorable catalysts in direct formic acid fuel cells.

  5. Catalytic Hydrotreatment of Alcell Lignin Using Supported Ru, Pd, and Cu Catalysts

    NARCIS (Netherlands)

    Kloekhorst, Arjan; Heeres, Hero

    2015-01-01

    A catalyst screening study on the catalytic hydrotreatment of Alcell lignin in a batch setup was performed using supported Ru (C, Al2O3,TiO2), Pd (C, Al2O3), and a Cu/ZrO2 catalyst with the objective to determine the best catalyst for high yields of biobased aromatics and alkylphenolics. Experiments

  6. The role of bridging ligand in hydrogen generation by photocatalytic Ru/Pd assemblies

    NARCIS (Netherlands)

    Bindra, Gurmeet Singh; Schulz, Martin; Paul, Avishek; Groarke, Robert; Soman, Suraj; Inglis, Jane L.; Browne, Wesley R.; Pfeffer, Michael G.; Rau, Sven; MacLean, Brian J.; Pryce, Mary T.; Vos, Johannes G.

    2012-01-01

    The synthesis and characterisation of two terpyridine based ruthenium/palladium heteronuclear compounds are presented. The photocatalytic behaviour of the Ru/Pd complex containing the linear 2,2':5',2 ''-terpyridine bridge (1a) and its analogue the non-linear 2,2':6',2 ''-terpyridine bridge (2a) are

  7. The role of bridging ligand in hydrogen generation by photocatalytic Ru/Pd assemblies

    NARCIS (Netherlands)

    Bindra, Gurmeet Singh; Schulz, Martin; Paul, Avishek; Groarke, Robert; Soman, Suraj; Inglis, Jane L.; Browne, Wesley R.; Pfeffer, Michael G.; Rau, Sven; MacLean, Brian J.; Pryce, Mary T.; Vos, Johannes G.

    2012-01-01

    The synthesis and characterisation of two terpyridine based ruthenium/palladium heteronuclear compounds are presented. The photocatalytic behaviour of the Ru/Pd complex containing the linear 2,2':5',2 ''-terpyridine bridge (1a) and its analogue the non-linear 2,2':6',2 ''-terpyridine bridge (2a) are

  8. Carbon-supported Pd-Ir catalyst as anodic catalyst in direct formic acid fuel cell

    Science.gov (United States)

    Wang, Xin; Tang, Yawen; Gao, Ying; Lu, Tianhong

    It was reported for the first time that the electrocatalytic activity of the Carbon-supported Pd-Ir (Pd-Ir/C) catalyst with the suitable atomic ratio of Pd and Ir for the oxidation of formic acid in the direct formic acid fuel cell (DFAFC) is better than that of the Carbon-supported Pd (Pd/C) catalyst, although Ir has no electrocatalytic activity for the oxidation of formic acid. The potential of the anodic peak of formic acid at the Pd-Ir/C catalyst electrode with the atomic ratio of Pd and Ir = 5:1 is 50 mV more negative than that and the peak current density is 13% higher than that at the Pd/C catalyst electrode. This is attributed to that Ir can promote the oxidation of formic acid at Pd through the direct pathway because Ir can decrease the adsorption strength of CO on Pd. However, when the content of Ir in the Pd-Ir/C catalyst is too high the electrocatalytic activity of the Pd-Ir/C catalyst would be decreased because Ir has no electrocatalytic activity for the oxidation of formic acid.

  9. Mesoporous silica nanoparticle supported PdIr bimetal catalyst for selective hydrogenation, and the significant promotional effect of Ir

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hui; Huang, Chao; Yang, Fan [The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China); Yang, Xu [Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou (China); Du, Li [The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China); Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou (China); Liao, Shijun, E-mail: chsjliao@scut.edu.cn [The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China); Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou (China)

    2015-12-01

    Graphical abstract: A mesoporous silica nanoparticle (MSN) supported bimetal catalyst, PdIr/MSN, was prepared by a facile impregnation and hydrogen reduction method. The strong promotional effect of Ir was observed and thoroughly investigated. At the optimal molar ratio of Ir to Pd (N{sub Ir}/N{sub Pd} = 0.1), the activity of PdIr{sub 0.1}/MSN was up to eight times and 28 times higher than that of monometallic Pd/MSN and Ir/MSN, respectively. The catalysts were characterized comprehensively by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and hydrogen temperature programmed reduction, which revealed that the promotional effect of Ir may be due to the enhanced dispersion of active components on the MSN, and to the intensified Pd–Ir electronic interaction caused by the addition of Ir. - Highlights: • Mesoporous nanoparticles were synthesized and used as support for metal catalyst. • PdIr bimetallic catalyst exhibited significantly improved hydrogenation activity. • The strong promotion of Ir was recognized firstly and investigated intensively. • PdIr exhibits 18 times higher activity than Pd to the hydrogenation of nitrobenzene. - Abstract: A mesoporous silica nanoparticle (MSN) supported bimetal catalyst, PdIr/MSN, was prepared by a facile impregnation and hydrogen reduction method. The strong promotional effect of Ir was observed and thoroughly investigated. At the optimal molar ratio of Ir to Pd (N{sub Ir}/N{sub Pd} = 0.1), the activity of PdIr{sub 0.1}/MSN was up to eight times and 28 times higher than that of monometallic Pd/MSN and Ir/MSN, respectively. The catalysts were characterized comprehensively by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and hydrogen temperature programmed reduction, which revealed that the promotional effect of Ir may be due to the enhanced dispersion of active components on the MSN, and to the intensified Pd–Ir electronic interaction

  10. High-activity PtRuPd/C catalyst for direct dimethyl ether fuel cells.

    Science.gov (United States)

    Li, Qing; Wen, Xiaodong; Wu, Gang; Chung, Hoon T; Gao, Rui; Zelenay, Piotr

    2015-06-22

    Dimethyl ether (DME) has been considered as a promising alternative fuel for direct-feed fuel cells but lack of an efficient DME oxidation electrocatalyst has remained the challenge for the commercialization of the direct DME fuel cell. The commonly studied binary PtRu catalyst shows much lower activity in DME than methanol oxidation. In this work, guided by density functional theory (DFT) calculation, a ternary carbon-supported PtRuPd catalyst was designed and synthesized for DME electrooxidation. DFT calculations indicated that Pd in the ternary PtRuPd catalyst is capable of significantly decreasing the activation energy of the CO and CH bond scission during the oxidation process. As evidenced by both electrochemical measurements in an aqueous electrolyte and polymer-electrolyte fuel cell testing, the ternary catalyst shows much higher activity (two-fold enhancement at 0.5 V in fuel cells) than the state-of-the-art binary Pt50 Ru50 /C catalyst (HiSPEC 12100).

  11. Hyperfine specific heats of PrX 2 ( X = Ir, Pt, Rh, Ru) laves phase compounds

    Science.gov (United States)

    Greidanus, F. J. A. M.; de Jongh, L. J.; Huiskamp, W. J.; Buschow, K. H. J.

    1980-01-01

    Specific heat data below 1 K for the C-15 compounds PrX 2 (X = Ir, Pt, Rh, Ru) reveal Schottky-type anomalies, ascribed to hyperfine interactions. Apparently the 4f-moments are magnetically ordered. The values deduced for these moments are only ≈ 70% of that for J = 4, indicating that the Pr 3+ moment is partially quenched by the crystal field.

  12. Solid solution alloy nanoparticles of immiscible Pd and Ru elements neighboring on Rh: changeover of the thermodynamic behavior for hydrogen storage and enhanced CO-oxidizing ability.

    Science.gov (United States)

    Kusada, Kohei; Kobayashi, Hirokazu; Ikeda, Ryuichi; Kubota, Yoshiki; Takata, Masaki; Toh, Shoichi; Yamamoto, Tomokazu; Matsumura, Syo; Sumi, Naoya; Sato, Katsutoshi; Nagaoka, Katsutoshi; Kitagawa, Hiroshi

    2014-02-05

    Pd(x)Ru(1-x) solid solution alloy nanoparticles were successfully synthesized over the whole composition range through a chemical reduction method, although Ru and Pd are immiscible at the atomic level in the bulk state. From the XRD measurement, it was found that the dominant structure of Pd(x)Ru(1-x) changes from fcc to hcp with increasing Ru content. The structures of Pd(x)Ru(1-x) nanoparticles in the Pd composition range of 30-70% consisted of both solid solution fcc and hcp structures, and both phases coexist in a single particle. In addition, the reaction of hydrogen with the Pd(x)Ru(1-x) nanoparticles changed from exothermic to endothermic as the Ru content increased. Furthermore, the prepared Pd(x)Ru(1-x) nanoparticles demonstrated enhanced CO-oxidizing catalytic activity; Pd0.5Ru0.5 nanoparticles exhibit the highest catalytic activity. This activity is much higher than that of the practically used CO-oxidizing catalyst Ru and that of the neighboring Rh, between Ru and Pd.

  13. Research on Electrochemical Behavior of Ti-Ir-Ru Anode Coating in Electrolytic Antifouling of Flowing Brine

    Science.gov (United States)

    Liang, Chenghao; Huang, Naibao

    2009-11-01

    By electrochemical techniques, the electrochemical behavior of Ti-Ir-Ru anode coating was studied in electrolytic antifouling of flowing brine. The effect of the brine’s flow rate and the anode/cathode interval on electrolysis was also considered. The results indicated that the brine’s flow rate had remarkable effect on the characteristic of the Ti-Ir-Ru anode. The electrolytic voltage and the evolved active chlorine concentration of Ti-Ir-Ru anode increased with increasing flow rate. Its energy consumption displayed the same variable rule as the electrolytic voltage. But the current density reduced with increasing flow rate. Increasing flow rate favored attenuation of the thickness of mass-transfer control layer and expediting the oxygen’s mass transfer, which accelerated the cathode polarization and the oxygen absorption reaction. The maximal current efficiency for Ti-Ir-Ru anode was obtained at the anode/cathode interval of 5 cm with the current density of 60 mA/cm2. At this point, Ti-Ir-Ru anode also had relatively low electrolytic voltage. The above operating procedure was ideal for electrolyzing flowing brine using Ti-Ir-Ru anode coating.

  14. Significantly Enhanced Hydrogen Evolution Activity of Freestanding Pd-Ru Distorted Icosahedral Clusters with less than 600 Atoms.

    Science.gov (United States)

    Dai, Zhihui; Liu, Suli; Zhang, Qinghua; Bao, Jianchun; Li, Yafei; Gu, Lin

    2017-07-24

    Freestanding metal nanoclusters can tune, precisely and effectively, the Gibbs free energy (ΔGH) of atomic hydrogen on the surface of materials. This enables the enhancement of hydrogen evolution activity. In this paper, we report a study of freestanding Pd-Ru distorted icosahedral clusters (ico-clusters) with less than 600 atoms using a simple one-pot synthesis method. This Pd-Ru ico-cluster can be used as an efficient electrocatalyst for the hydrogen evolution reaction (HER) in acidic water, which is a promising alternative to Pt. The experimental and theoretical results suggest that the fcc freestanding Pd-Ru distorted ico-clusters with less than 600 atoms ensure increased active edges and distorted defect sites that reduce the coordination number for the atoms on the catalyst surface. Furthermore, Ru is a more effective hydrogen dissociation source, while Pd has a better hydrogen storage function. Pd-Ru can tune the ΔGH of atomic hydrogen adsorbed on a catalyst and reach an optimal equilibrium state that improves the HER performance. Our studies represent a robust approach towards the development of freestanding Pd-Ru distorted ico-clusters and advanced catalysts with non-Pt content for HER and many other heterogeneous reactions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Single-particle isomeric states in 121Pd and 117Ru

    CERN Document Server

    Lalkovski, S; Bacelar, A M Denis; Gorska, M; Pietri, S; Podolyak, Zs; Bednarczyk, P; Caceres, L; Casarejos, E; Cullen, I J; Doornenbal, P; Farrelly, G F; Garnsworthy, A B; Geissel, H; Gelletly, W; Gerl, J; Grcebosz, J; Hinke, C; Ilie, G; Jaworski, G; Kisyov, S; Kojouharov, I; Kurz, N; Myalski, S; Palacz, M; Prokopowicz, W; Regan, P H; Schaffner, H; Steer, S; Tashenov, S; Walker, P M; Wollersheim, H J; Zhekova, M

    2011-01-01

    Neutron-rich nuclei were populated in a relativistic fission of 238U. Gamma-rays with energies of 135 keV and 184 keV were associated with two isomeric states in 121Pd and 117Ru. Half-lives of 0.63(5) microseconds and 2.0(3) micrisecondss were deduced and the isomeric states were interpreted in terms of deformed single-particle states.

  16. Extended IBA consistent-Q formalism applied to Ru and Pd isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Bucurescu, D.; Cata, G.; Cutoiu, D.; Constantinescu, G.; Ivascu, M.; Zamfir, N.V.

    1986-08-01

    A consistent-Q formalism extended to an IBA-1 hamiltonian applicable also in the U(5) limit, is applied to Ru and Pd isotopes with N around 60. A good description of energy levels and E2 transition in these nuclei is obtained. The model is able to reproduce the main features of this transitional region, characterized by both rigid triaxial deformation and ..gamma..-softness.

  17. Ánodos de Pt-Ru y Pt-Ir para Celdas de Combustible Alimentadas con Metano y Propano Directo Pt-Ru and Pt-Ir Anodes for Direct Methane and Propane Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Bibian A Hoyos

    2007-01-01

    Full Text Available En este trabajo se evalúa el efecto de la temperatura en el desempeño de celdas de combustible de membrana de intercambio protónico alimentadas con metano y propano, utilizando oxígeno como alimentación en el cátodo. Para la oxidación de los combustibles en los ánodos, se probaron cinco catalizadores soportados en carbón: Pt, Pt85Ru15, Pt50Ru50, Pt90Ir10 y Pt50Ir50. Como catalizador en el cátodo se usó platino puro soportado en carbón. El desempeño de las celdas de combustible fue evaluado mediante curvas de polarización obtenidas a partir de los datos corriente-potencial. Los resultados indican que la oxidación de metano se ve favorecida a altas temperaturas sobre los catalizadores Pt90/Ir10, Pt50/Ir50 y Pt50/Ru50. A bajas temperaturas los mejores catalizadores resultaron ser Pt y Pt85/Ru15. La mezcla bimetálica Pt85/Ru15 fue la que presentó mejor desempeño para llevar a cabo la oxidación de propano a 30 °C.In this paper, the effect of temperature in the performance of proton exchange membrane fuel cells feed with methane and propane, using oxygen as feed to the cathode, is presented. For the fuel oxidation in the anodes, five carbon supported catalysts were tested: Pt, Pt85/Ru15, Pt50/Ru50, Pt90/Ir10, and Pt50/Ir50. Carbon-supported pure platinum was used as catalysts in the cathode side. The performance of the fuel cells was evaluated by polarization curves obtained from the current-potential data. Results indicate that methane oxidation is favoured at high temperatures on the Pt90/Ir10, Pt50/Ir50 and Pt50/Ru50 catalysts. At low temperatures the best catalysts were Pt and Pt85/Ru15. The Pt85/Ru15 bimetallic mixture showed the best performance to carry out propane oxidation at 30 °C.

  18. A Synthetic Pseudo-Rh: NOx Reduction Activity and Electronic Structure of Pd-Ru Solid-solution Alloy Nanoparticles.

    Science.gov (United States)

    Sato, Katsutoshi; Tomonaga, Hiroyuki; Yamamoto, Tomokazu; Matsumura, Syo; Zulkifli, Nor Diana Binti; Ishimoto, Takayoshi; Koyama, Michihisa; Kusada, Kohei; Kobayashi, Hirokazu; Kitagawa, Hiroshi; Nagaoka, Katsutoshi

    2016-06-24

    Rh is one of the most important noble metals for industrial applications. A major fraction of Rh is used as a catalyst for emission control in automotive catalytic converters because of its unparalleled activity toward NOx reduction. However, Rh is a rare and extremely expensive element; thus, the development of Rh alternative composed of abundant elements is desirable. Pd and Ru are located at the right and left of Rh in the periodic table, respectively, nevertheless this combination of elements is immiscible in the bulk state. Here, we report a Pd-Ru solid-solution-alloy nanoparticle (PdxRu1-x NP) catalyst exhibiting better NOx reduction activity than Rh. Theoretical calculations show that the electronic structure of Pd0.5Ru0.5 is similar to that of Rh, indicating that Pd0.5Ru0.5 can be regarded as a pseudo-Rh. Pd0.5Ru0.5 exhibits better activity than natural Rh, which implies promising applications not only for exhaust-gas cleaning but also for various chemical reactions.

  19. Ir-Ru/Al2O3 catalysts used in satellite propulsion

    Directory of Open Access Journals (Sweden)

    T.G. Soares Neto

    2003-09-01

    Full Text Available Ir/Al2O3, Ir-Ru/Al2O3 and Ru/Al2O3, catalysts with total metal contents of 30% were prepared using the methods of incipient wetness and incipient coimpregnation wetness and were tested in a 2N microthruster. Their performances were then compared with that of the Shell 405 commercial catalyst (30% Ir/Al2O3. Tests were performed in continuous and pulsed regimes, where there are steep temperature and pressure gradients, from ambient values up to 650 ºC and 14 bar. Performance stability, thrust produced, temperature and stagnation pressure in the chamber and losses of mass were analyzed and compared to the corresponding parameters in Shell 405 tests. It was observed that the performance of all the above-mentioned catalysts was comparable to that of the commercial one, except for in loss of mass, where the values was higher, which was attributed to the lower mechanical resistance of the support.

  20. Surface noble metal modified PdM/C (M = Ru, Pt, Au) as anode catalysts for direct ethanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Han; Huang, Tao, E-mail: huangt@fudan.edu.cn; Yu, Aishui, E-mail: asyu@fudan.edu.cn

    2016-08-15

    In this article, we studied the surface noble metal modification on Pd nanoparticles, other than the homogeneous or core-shell structure. The surface modification will lead to the uneven constitution within the nanoparticles and thus more obvious optimization effect toward the catalyst brought by the lattice deformation. The surface of the as-prepared Pd nanoparticles was modified with Ru, Pt or Au by a moderate and green approach, respectively. XPS results confirm the interactive electron effects between Pd and the modified noble metal. Electrochemical measurements show that the surface noble metal modified catalysts not only show higher catalytic activity, but also better stability and durability. The PdM/C catalysts all exhibit good dispersion and very little agglomeration after long-term potential cycles toward ethanol oxidation. With only 10% metallic atomic ratio of Au, PdAu/C catalyst shows extraordinary catalytic activity and stability, the peak current reaches 1700 mA mg{sup −1} Pd, about 2.5 times that of Pd/C. Moreover, the PdAu/C maintains 40% of the catalytic activity after 4500 potential cycles. - Highlights: • Pd-based catalysts with complicated exposed facets. • Much enhanced electrocatalytic activity and stability with about 10% noble metal M (M = Ru, Pt, Au) on Pd nanoparticles. • The outstanding electrocatalytic performance of PdAu/C towards ethanol oxidation after the Au modification.

  1. Enhanced formic acid electro-oxidation reaction on ternary Pd-Ir-Cu/C catalyst

    Science.gov (United States)

    Chen, Jinwei; Zhang, Jie; Jiang, Yiwu; Yang, Liu; Zhong, Jing; Wang, Gang; Wang, Ruilin

    2015-12-01

    Aim to further reduce the cost of Pd-Ir for formic acid electro-oxidation (FAEO), the Cu was used to construct a ternary metallic alloy catalyst. The prepared catalysts are characterized using XRD, TGA, EDX, TEM, XPS, CO-stripping, cyclic voltammetry and chronoamperometry. It is found that the Pd18Ir1Cu6 nanoparticles with a mean size of 3.3 nm are highly dispersed on carbon support. Componential distributions on catalyst are consistent with initial contents. Electrochemical measurements show that the PdIrCu/C catalyst exhibits the highest activity for FAEO. The mass activity of Pd in Pd18Ir1Cu6/C at 0.16 V (vs. SCE) is about 1.47, 1.62 and 2.08 times as high as that of Pd18Cu6/C, Pd18Ir1/C and Pd/C, respectively. The activity enhancement of PdIrCu/C should be attributed to the weakened CO adsorption strength and the removal of adsorbed intermediates at lower potential with the addition of Cu and Ir.

  2. Effect of pressure on the Curie temperature of Mn2RuSn and Mn2PdSn

    Science.gov (United States)

    Adachi, Y.; Watanabe, T.; Kanomata, T.; Hayasaka, M.; Endo, K.; Nishihara, H.; Xu, X.; Kainuma, R.

    2017-04-01

    Effect of pressure on the Curie temperature TC of the Mn-rich Heusler alloys Mn2RuSn and Mn2PdSn has been investigated by measuring the temperature dependence of initial permeability at various pressures up to 10 kbar. It was found that the Curie temperatures of Mn2RuSn and Mn2PdSn decrease with increasing pressure. The pressure derivatives of TC were estimated to be -0.59 K/kbar for Mn2RuSn and -0.80 K/kbar for Mn2PdSn. On the basis of the experimental results, the relationship between the magnetic transition temperature and the Mn-Mn distance is discussed.

  3. Optimization of the Gilbert damping constant by annealing CoFeB films sandwiched by Ta, Ru, and Pd layers

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Cheong-Gu; Moon, Joon; Kim, Joo-Sung; Choe, Sug-Bong [Seoul National University, Seoul (Korea, Republic of); Moon, Cheol-Hyun; Min, Byoung-Chul [Korea Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Sang-Il; Park, Seung-Young [Korea Basic Science Institute, Daejeon (Korea, Republic of)

    2014-11-15

    The effects of annealing on the Gilbert damping constant and the magnetic properties are investigated in CoFeB films sandwiched by either Ta, Ru, or Pd layers. As the annealing temperature increases, the damping constant is found to be slightly decreased first and then, rapidly increased. The minimum damping constant is, thus, obtained with a 300 .deg. C-annealed Ta/CoFeB/Ta film while the samples with Ru and Pd layers exhibit their minimum at 200 .deg. C. The coercive field also exhibits a behavior similar to the damping constant; thus, an empirical correlation between them is proposed.

  4. Communication: Enhanced oxygen reduction reaction and its underlying mechanism in Pd-Ir-Co trimetallic alloys

    Science.gov (United States)

    Ham, Hyung Chul; Manogaran, Dhivya; Lee, Kang Hee; Kwon, Kyungjung; Jin, Seon-ah; You, Dae Jong; Pak, Chanho; Hwang, Gyeong S.

    2013-11-01

    Based on a combined density functional theory and experimental study, we present that the electrochemical activity of Pd3Co alloy catalysts toward oxygen reduction reaction (ORR) can be enhanced by adding a small amount of Ir. While Ir tends to favorably exist in the subsurface layers, the underlying Ir atoms are found to cause a substantial modification in the surface electronic structure. As a consequence, we find that the activation barriers of O/OH hydrogenation reactions are noticeably lowered, which would be mainly responsible for the enhanced ORR activity. Furthermore, our study suggests that the presence of Ir in the near-surface region can suppress Co out-diffusion from the Pd3Co substrate, thereby improving the durability of Pd-Ir-Co catalysts. We also discuss the relative roles played by Ir and Co in enhancing the ORR activity relative to monometallic Pd catalysts.

  5. In situ spectroscopic ellipsometry during atomic layer deposition of Pt, Ru and Pd

    Science.gov (United States)

    Leick, N.; Weber, J. W.; Mackus, A. J. M.; Weber, M. J.; van de Sanden, M. C. M.; Kessels, W. M. M.

    2016-03-01

    The preparation of ultra-thin platinum-group metal films, such as Pt, Ru and Pd, by atomic layer deposition (ALD) was monitored in situ using spectroscopic ellipsometry in the photon energy range of 0.75-5 eV. The metals’ dielectric function was parametrized using a ‘flexible’ Kramers-Kronig consistent dielectric function because it was able to provide accurate curve shape control over the optical response of the metals. From this dielectric function, it was possible to extract the film thickness values during the ALD process. The important ALD process parameters, such as the nucleation period and growth per cycle of Pt, Ru and Pd could be determined from the thickness evolution. In addition to process parameters, the film resistivity in particular could be extracted from the modeled dielectric function. Spectroscopic ellipsometry thereby revealed itself as a feasible and valuable technique to be used in research and development applications, as well as for process monitoring during ALD.

  6. On the antitumor properties of novel cyclometalated benzimidazole Ru(II), Ir(III) and Rh(III) complexes.

    Science.gov (United States)

    Yellol, Gorakh S; Donaire, Antonio; Yellol, Jyoti G; Vasylyeva, Vera; Janiak, Christoph; Ruiz, José

    2013-12-21

    Smart design and efficient synthesis of benzimidazole Ru, Ir and Rh cyclometalated complexes are reported with promising cytotoxic activity against HT29, T47D, A2780 and A2780cisR cancer cell lines. Their apoptosis, accumulation, cell cycle arrest, protein binding and DNA binding effects are also discussed.

  7. Ligand Effects on the Hydrogenation of Biomass-Inspired Substrates with Bifunctional Ru, Ir, and Rh Complexes

    NARCIS (Netherlands)

    Jansen, E.; Jongbloed, L.S.; Tromp, D.S.; Lutz, M.; de Bruin, B.; Elsevier, C.J.

    2013-01-01

    We herein report on the application and structural investigation of a new set of complexes that contain bidentate N-heterocyclic carbenes (NHCs) and primary amine moieties of the type [M(arene)Cl(L)] [M=Ru, Ir, or Rh; arene=p-cymene or pentamethylcyclopentadienyl; L=1-(2-aminophenyl)-3-(n-alkyl)imid

  8. Oxygen reduction behavior of RuO{sub 2}/Ti, IrO{sub 2}/Ti and IrM (M: Ru, Mo, W, V) O{sub x}/Ti binary oxide electrodes in a sulfuric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Takasu, Yoshio; Yoshinaga, Norihiro; Sugimoto, Wataru [Department of Fine Materials Engineering, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567 (Japan)

    2008-04-15

    Some oxide catalysts, such as RuO{sub 2}/Ti, IrO{sub 2}/Ti and IrM(M: Ru, Mo, W, V)O{sub x}/Ti binary oxide electrodes, were prepared by using a dip-coating method on a Ti substrate. Their catalytic behavior for the oxygen reduction reaction (ORR) was evaluated by cyclic voltammetry in 0.5 M H{sub 2}SO{sub 4} at 60 C. These catalysts were found to exhibit considerably high activity, and the most active one among them was Ir{sub 0.6}V{sub 0.4}O{sub 2}/Ti prepared at 450 C, showing onset potential for the ORR at about 0.86 V-0.90 (vs RHE). (author)

  9. Impact of IrRu oxygen evolution reaction catalysts on Pt nanostructured thin films under start-up/shutdown cycling

    Science.gov (United States)

    Cullen, David A.; More, Karren L.; Atanasoska, Ljiljana L.; Atanasoski, Radoslav T.

    2014-12-01

    Electron microscopy and X-ray photoelectron spectroscopy (XPS) were utilized to study the role of oxygen evolution reaction (OER) catalysts in mitigating degradation arising from start-up/shutdown events. Pt nanostructured thin films (NSTF) were coated with a Ru0.1Ir0.9 OER catalyst at loadings ranging from 1 to 10 μg cm-2 and submitted to 5000 potential cycles within a membrane electrode assembly. Analysis of the as-deposited catalyst showed that the Ir and Ru coating is primarily metallic, and further evidence is provided to support the previously reported interaction between Ru and the perylene-red support. Aberration-corrected scanning transmission electron microscopy and energy dispersive X-ray spectroscopy were used to observe the impact of the OER catalysts on Pt dissolution and migration into the membrane. Elemental mapping showed a high percentage of the Ir catalyst was maintained on the NSTF whisker surfaces following testing. The presence of the OER catalysts greatly reduced the smoothing of the Pt NSTF whiskers, which has been correlated with Pt dissolution and losses in electrochemically active surface area. The dissolution of both Ir and Pt led to the formation of IrPt nanoparticle clusters in the membrane close to the cathode, as well as the formation of a Pt band deeper in the membrane.

  10. Synthesis, structural, optical and anti-rheumatic activity of metal complexes derived from (E)-2-amino-N-(1-(2-aminophenyl)ethylidene)benzohydrazide (2-AAB) with Ru(III), Pd(II) and Zr(IV).

    Science.gov (United States)

    Hosny, Nasser Mohammed; Sherif, Yousery E

    2015-02-05

    Three new metal complexes derived from Pd(II), Ru(III) and Zr(IV) with (E)-2-amino-N-(1-(2-aminophenyl)ethylidene)benzohydrazide (2-AAB) have been synthesized. The isolated complexes were characterized by elemental analyses, FT-IR, UV-Vis, ES-MS, (1)H NMR, XRD, thermal analyses (TGA and DTA) and conductance. The morphology and the particle size were determined by transmittance electron microscope (TEM). The results showed that, the ligand coordinates to Pd(II) in the enol form, while it coordinates to Ru(III) and Zr(IV) in the keto form. A square planar geometry is suggested for Pd(II) complex and octahedral geometries are suggested for Ru(III) and Zr(IV) complexes. The optical band gaps of the isolated complexes were measured and indicated the semi-conductivity nature of the complexes. The anti-inflammatory and analgesic activities of the ligand and its complexes showed that, Ru(III) complex has higher effect than the well known drug "meloxicam".

  11. Structural, electronic, elastic and superconducting properties of noble metal nitrides MN{sub 2} (M = Ru, Rh, Pd)

    Energy Technology Data Exchange (ETDEWEB)

    Puvaneswari, S. [Department of Physics, E.M.G. Yadava Women' s College, Madurai, Tamilnadu 625 014 (India); Rajeswarapalanichamy, R., E-mail: rrpcaspd2003@gmail.com [Department of Physics, N.M.S.S. Vellaichamy Nadar College, Madurai, Tamilnadu 625019 (India); Sudha Priyanga, G. [Department of Physics, N.M.S.S. Vellaichamy Nadar College, Madurai, Tamilnadu 625019 (India)

    2015-02-01

    The structural stability, electronic structure, elastic and superconducting properties of noble metal nitrides MN{sub 2} (M = Ru, Rh, Pd) are investigated in tetragonal (P4/mbm), fluorite (Fm3m), orthorhombic (Pnnm), pyrite (Pa-3) and hexagonal (P6/mmm) phases using first principles calculations. The calculated lattice parameters are in good agreement with other theoretical results. Among the considered structures, RhN{sub 2} and PdN{sub 2} are found to be most stable in tetragonal structure, whereas RuN{sub 2} is stable in fluorite structure. A sequence of structural phase transition is predicted under high pressure in these metal nitrides. The electronic structure reveals that these nitrides are metallic. These metal nitrides are found to be covalent, ionic and metallic in the stable phase. The observations show that these metal nitrides are mechanically stable at ambient condition. The superconducting transition temperatures for RuN{sub 2}, RhN{sub 2} and PdN{sub 2} are found to be 1.65 K, 5.01 K and 8.7 K respectively. - Highlights: • Electronic, structural and elastic properties of RuN{sub 2}, RhN{sub 2} and PdN{sub 2} are studied. • A pressure induced structural phase transition is predicted. • Electronic structure reveals that these materials exhibit metallic behavior. • High bulk modulus indicates that RuN{sub 2}, RhN{sub 2} and PdN{sub 2} are superhard materials. • Superconducting temperature values are reported.

  12. Room temperature biogenic synthesis of multiple nanoparticles (Ag, Pd, Fe, Rh, Ni, Ru, Pt, Co, and Li) by Pseudomonas aeruginosa SM1

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Sarvesh Kumar; Constanti, Magda, E-mail: magdalena.constanti@urv.cat [Universitat Rovira i Virgili, Departament d' Enginyeria Quimica (Spain)

    2012-03-15

    Room temperature biosynthesis of Ag, Pd, Fe, Rh, Ni, Ru, Pt, Co, and Li nanoparticles was achieved using Pseudomonas aeruginosa SM1 without the addition of growth media, electron donors, stabilizing agents, preparation of cell/cell-free extract or temperature, and pH adjustments. The resulting nanoparticles were characterized by Transmission electron microscopy and X-ray diffraction. It was observed that P. aeruginosa SM1 is capable of producing both intracellular (Co and Li) and extracellular (Ag, Pd, Fe, Rh, Ni, Ru, and Pt) nanoparticles in both crystalline and amorphous state. The FT-IR spectra clearly showed the presence of primary and secondary amines which may be responsible for the reduction and subsequent stabilization of the resulting extracellular nanoparticles which were obtained as a one-step process. This suggests toward an unknown 'selection mechanism' that reduces certain metal ions and allows others to enter the cell membrane. Finally, in this first of its kind study, single strain of bacteria was used to produce several different mono-metallic nanoparticles.

  13. Room temperature biogenic synthesis of multiple nanoparticles (Ag, Pd, Fe, Rh, Ni, Ru, Pt, Co, and Li) by Pseudomonas aeruginosa SM1

    Science.gov (United States)

    Srivastava, Sarvesh Kumar; Constanti, Magda

    2012-03-01

    Room temperature biosynthesis of Ag, Pd, Fe, Rh, Ni, Ru, Pt, Co, and Li nanoparticles was achieved using Pseudomonas aeruginosa SM1 without the addition of growth media, electron donors, stabilizing agents, preparation of cell/cell-free extract or temperature, and pH adjustments. The resulting nanoparticles were characterized by Transmission electron microscopy and X-ray diffraction. It was observed that P. aeruginosa SM1 is capable of producing both intracellular (Co and Li) and extracellular (Ag, Pd, Fe, Rh, Ni, Ru, and Pt) nanoparticles in both crystalline and amorphous state. The FT-IR spectra clearly showed the presence of primary and secondary amines which may be responsible for the reduction and subsequent stabilization of the resulting extracellular nanoparticles which were obtained as a one-step process. This suggests toward an unknown "selection mechanism" that reduces certain metal ions and allows others to enter the cell membrane. Finally, in this first of its kind study, single strain of bacteria was used to produce several different mono-metallic nanoparticles.

  14. Stability and ordering properties of fcc alloys based on Rh, Ir, Pd, and Pt

    Science.gov (United States)

    Turchi, P. E. A.; Drchal, V.; Kudrnovský, J.

    2006-08-01

    Stability properties and ordering trends for the six face-centered cubic binary combinations of the four transition metals Rh, Ir, Pd, and Pt are examined in the context of electronic structure calculations. The method is based on a Green’s function description of the electronic structure of random alloys. Configurational order is treated within the generalized perturbation method. On one hand, the three alloys Pd-Rh, Pd-Ir, and Pt-Ir that have been studied experimentally are confirmed to behave like phase-separating systems. On the other hand, the other three mixtures Pd-Pt, Rh-Ir, and Pt-Rh, for which phase-separating trends have been inferred from experiments, are found to display chemical order with ordering of the (1 0 0) and (11/20) family types and a mixture of both, respectively. The origin of these results is discussed in terms of electronic structure properties.

  15. σ-Aromaticity in polyhydride complexes of Ru, Ir, Os, and Pt.

    Science.gov (United States)

    Jimenez-Izal, Elisa; Alexandrova, Anastassia N

    2016-04-28

    Transition-metal hydrides represent a unique class of compounds, which are essential for catalysis, organic synthesis, and hydrogen storage. In this work we study IrH5(PPh3)2, (RuH5(P(i)Pr3)2)(-), (OsH5(P(i)Pr3)2)(-), and OsH4(PPhMe2)3 polyhydride complexes, inspired by the recent discovery of the σ-aromatic PtZnH5(-) cluster anion. The distinctive feature of these molecules is that, like in the PtZnH5(-) cluster, the metal is five-fold coordinated in-plane, and holds additional ligands at the axial positions. This work shows that the unusual coordination in these compounds indeed can be explained by σ-aromaticity in the pentagonal arrangement, stabilized by the atomic orbitals on the metal. Based on this newly elucidated bonding principle, we additionally propose a new family of polyhydrides that display a uniquely high coordination. We also report the first indications of how aromaticity may impact the reactivity of these molecules.

  16. Epitaxial growth of unusual 4H hexagonal Ir, Rh, Os, Ru and Cu nanostructures on 4H Au nanoribbons

    KAUST Repository

    Fan, Zhanxi

    2016-09-12

    Metal nanomaterials normally adopt the same crystal structure as their bulk counterparts. Herein, for the first time, the unusual 4H hexagonal Ir, Rh, Os, Ru and Cu nanostructures have been synthesized on 4H Au nanoribbons (NRBs) via solution-phase epitaxial growth under ambient conditions. Interestingly, the 4H Au NRBs undergo partial phase transformation from 4H to face-centered cubic (fcc) structures after the metal coating. As a result, a series of polytypic 4H/fcc bimetallic Au@M (M = Ir, Rh, Os, Ru and Cu) core-shell NRBs has been obtained. We believe that the rational crystal structure-controlled synthesis of metal nanomaterials will bring new opportunities for exploring their phase-dependent physicochemical properties and promising applications.

  17. Specific heat, resistivity, and AC susceptibility of the cubic PrX 2 compounds (X = Pt, Ru, Ir, Rh)

    Science.gov (United States)

    Greidanus, F. J. A. M.; Nieuwenhuys, G. J.; de Jongh, L. J.; Huiskamp, W. J.; Capel, H. W.; Buschow, K. H. J.

    1983-04-01

    Specific-heat, differential-susceptibility and electrical-resistivity measurements on PrX 2 (X = Ir, Pt, Rh, Ru) compounds reveal phase transitions at Tc = 11.2±0.5 K, 7.7±0.5 K, 7.9±0.5 Kand 33.9±0.5 K for X = Ir, Pt, Rh, and Ru, respective ly. From earlier neutron inelastic scattering experiments, the crystalline electric field levels of these compounds have been determined. The specific-heat results are compared with the results of a mean-field calculation, assuming bilinear exchange interactions. The presence of broad secondary maxima in the temperature dependence of the specific heat of PrRh 2, PrRu 2 and especially PrIr 2 can qualitatively be explained by the presence of biquadratic (quadrupolar) interactions. The behaviour of the susceptibility is in agreement with ferromagnetic ordering. The electrical resistivity drops markedly below Tc, and the dϱ/d T versus T curve is similar to that of the specific heat.

  18. Characterization of some synthetic Ru and Ir complexes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

    NARCIS (Netherlands)

    Lou, X.; Buijtenen, J. van; Bastiaansen, J.J.A.M.; Waal, B.F.M. de; Langeveld, B.M.W.; Dongen, J.L.J. van

    2005-01-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was applied to the analysis of Ru(OCOCF 3)2(CO)(PPh3)2, Ru(OCOC 3F7)2(CO)(PPh3)2, Ir(tBuppy)3 and Ir(ppy)2(acac) complexes. A troublesome problem in the MALDI-TOFMS characterization of these metal complexes is

  19. Characterization of some synthetic Ru and Ir complexes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

    NARCIS (Netherlands)

    Lou, X.; Buijtenen, J. van; Bastiaansen, J.J.A.M.; Waal, B.F.M. de; Langeveld, B.M.W.; Dongen, J.L.J. van

    2005-01-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was applied to the analysis of Ru(OCOCF 3)2(CO)(PPh3)2, Ru(OCOC 3F7)2(CO)(PPh3)2, Ir(tBuppy)3 and Ir(ppy)2(acac) complexes. A troublesome problem in the MALDI-TOFMS characterization of these metal complexes is

  20. Partition coefficients for Ni, Cu, Pd, Pt, Rh, and Ir between monosulfide solid solution and sulfide liquid and the formation of compositionally zoned Ni-Cu sulfide bodies by fractional crystallization of sulfide liquid

    DEFF Research Database (Denmark)

    Barnes, S.J.; Makovicky, E.; Makovicky, M.

    1996-01-01

    Many nickel–copper sulfide orebodies contain Cu- and Fe-rich portions. The Fe-rich ore is generally richer in Os, Ir, Ru, and Rh and poorer in Pt, Pd, and Au than the Cu-rich ore. In komatiite-hosted ores Ni tends to be concentrated in the Cu-rich ore, whereas in tholeiitic ores it tends to be co...

  1. CO adsorption over Pd nanoparticles: A general framework for IR simulations on nanoparticles

    Science.gov (United States)

    Zeinalipour-Yazdi, Constantinos D.; Willock, David J.; Thomas, Liam; Wilson, Karen; Lee, Adam F.

    2016-04-01

    CO vibrational spectra over catalytic nanoparticles under high coverages/pressures are discussed from a DFT perspective. Hybrid B3LYP and PBE DFT calculations of CO chemisorbed over Pd4 and Pd13 nanoclusters, and a 1.1 nm Pd38 nanoparticle, have been performed in order to simulate the corresponding coverage dependent infrared (IR) absorption spectra, and hence provide a quantitative foundation for the interpretation of experimental IR spectra of CO over Pd nanocatalysts. B3LYP simulated IR intensities are used to quantify site occupation numbers through comparison with experimental DRIFTS spectra, allowing an atomistic model of CO surface coverage to be created. DFT adsorption energetics for low CO coverage (θ → 0) suggest the CO binding strength follows the order hollow > bridge > linear, even for dispersion-corrected functionals for sub-nanometre Pd nanoclusters. For a Pd38 nanoparticle, hollow and bridge-bound are energetically similar (hollow ≈ bridge > atop). It is well known that this ordering has not been found at the high coverages used experimentally, wherein atop CO has a much higher population than observed over Pd(111), confirmed by our DRIFTS spectra for Pd nanoparticles supported on a KIT-6 silica, and hence site populations were calculated through a comparison of DFT and spectroscopic data. At high CO coverage (θ = 1), all three adsorbed CO species co-exist on Pd38, and their interdiffusion is thermally feasible at STP. Under such high surface coverages, DFT predicts that bridge-bound CO chains are thermodynamically stable and isoenergetic to an entirely hollow bound Pd/CO system. The Pd38 nanoparticle undergoes a linear (3.5%), isotropic expansion with increasing CO coverage, accompanied by 63 and 30 cm- 1 blue-shifts of hollow and linear bound CO respectively.

  2. Synthetic, structural and antifungal studies of coordination compounds of Ru(III, Rh(III and Ir(III with tetradentate Schiff bases

    Directory of Open Access Journals (Sweden)

    ANKITA SRIVASTAVA

    2006-09-01

    Full Text Available A series of octahedral Ru(III, Rh(III and Ir(III complexes have been prepared with tetradentate Schiff bases derived by condensing isatin with 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,2-diaminobenzene and 1,3-diaminobenzene. The obtained complexes were characterized on the basis of their elemental analyses, magnetic moment, conductance, IR, electronic, 1HNMR and FAB mass spectra, as well as thermal analyses. The Ru(III complexes are low spin paramagnetic, while Rh(III and Ir(III behave as diamagnetic complexes. The IR spectral data revealed that all the Schiff bases behave as tetradentate and are coordinated to Ru(III, Rh(III and Ir(III via nitrogen and oxygen. Antifungal studies of the ligands as well as their complexes were carried out by the agar plate method.

  3. Influence of rapid thermal annealing effect on electrical and structural properties of Pd/Ru Schottky contacts to n-type GaN

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, N. Nanda Kumar [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Reddy, V. Rajagopal, E-mail: reddy_vrg@rediffmail.com [Department of Physics, Sri Venkateswara University, Tirupati 517 502 (India); Choi, Chel-Jong [School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center (SPRC), Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2011-11-01

    Highlights: {yields} Annealing effects on the electrical and structural properties of Ru/Pd/n-GaN SBDs are studied. {yields} The optimum annealing temperature for Pd/Ru Schottky contact is 300 deg. C. {yields} Increase in SBH upon annealing at 300 deg. C could be attributed to the formation of gallide phases. {yields} The overall surface morphology of the Pd/Ru Schottky contacts on n-GaN is fairly smooth. - Abstract: Pd/Ru metallization scheme is fabricated on n-GaN as a Schottky contact, and the electrical and structural properties have been investigated as a function of annealing temperature by current-voltage (I-V), capacitance-voltage (C-V), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) measurements. As-deposited Ru/Pd/n-GaN contact yielded Schottky barrier height (SBH) of 0.67 eV (I-V) and 0.79 eV (C-V), respectively. Further, it is observed that the Schottky barrier height increases to 0.80 eV (I-V) and 0.96 eV (C-V) for the contact annealed at 300 deg. C. However, both I-V and C-V measurements indicate that the barrier height slightly decreased when the contacts are annealed at 400 deg. C and 500 deg. C. From the above observations, the optimum annealing temperature for Pd/Ru Schottky contact is 300 deg. C. Norde method is also employed to extract the barrier height of Pd/Ru Schottky contacts which are in good agreement with those obtained by the I-V technique. X-ray photoelectron spectroscopy results shows that the Ga 2p core-level shift towards the low-energy side for the contact annealed at 300 deg. C compared to the as-deposited contact. Based on the XPS and XRD results, the reason for the increase in SBH upon annealing at 300 deg. C could be attributed to the formation of gallide phases at the Ru/Pd/n-GaN interface vicinity. The AFM results showed that the overall surface morphology of the Pd/Ru Schottky contacts on n-GaN is fairly smooth. The above observations reveal that the Pd/Ru Schottky contact is attractive for high

  4. Enhanced formic acid electro-oxidation on PdIr nanoparticles prepared by ethylene glycol-assisted NaBH4 reduction process.

    Science.gov (United States)

    Chen, Jinwei; Wang, Gang; Wang, Xueqin; Tian, Jing; Zhu, Shifu; Wang, Ruilin

    2013-10-01

    The carbon supported PdIr nanoparticles were synthesized by an ethylene glycol-assisted NaBH4 reduction method, and the mass ratio of Pd to Ir was optimized. Then, their performances for formic acid electro-oxidation (FAEO) were investigated. The XRD and TEM characterizations show that the prepared PdIr/C catalysts have small mean size and good dispersion of PdIr nanoparticles. The electrochemical measurements demonstrate that the PdIr/C catalysts have greatly enhanced performance for FAEO compared with the Pd/C catalyst. The PdIr/C catalysts show higher current density and more than 50 mV negative shift of onset and peak potential than that of the Pd/C catalyst. With the optimal mass ratio of Pd to Ir, the PdIr/C-5 catalyst presents the highest catalytic activity for FAEO.

  5. Influence of hydrogen on the thermoelectric power of palladium alloyed with neighbouring elements: I. Pd/Ru/H and Pd/Rh/H alloys

    CERN Document Server

    Szafranski, A W

    2003-01-01

    Pd/Ru and Pd/Rh alloys have been loaded with hydrogen in high-pressure conditions. The resulting hydrogen contents were close to the stoichiometric composition, H/(Pd + Me) = 1. Lower hydrogen contents have been obtained by successive partial desorptions. The thermoelectric power and electrical resistance of one- and two-phase alloys have been measured simultaneously in the temperature range between 80 and 300 K. A Nordheim-Gorter type correlation of the two quantities has been observed in many cases and the partial thermopowers corresponding to electron-phonon scattering and lattice disorder could be determined. The observed anomalous behaviour of the total and partial thermopowers is attributed to virtual bound states of ruthenium or rhodium.

  6. Pd-Ir Core-Shell Nanocubes: A Type of Highly Efficient and Versatile Peroxidase Mimic.

    Science.gov (United States)

    Xia, Xiaohu; Zhang, Jingtuo; Lu, Ning; Kim, Moon J; Ghale, Kushal; Xu, Ye; McKenzie, Erin; Liu, Jiabin; Ye, Haihang

    2015-10-27

    Peroxidase mimics with dimensions on the nanoscale have received great interest as emerging artificial enzymes for biomedicine and environmental protection. While a variety of peroxidase mimics have been actively developed recently, limited progress has been made toward improving their catalytic efficiency. In this study, we report a type of highly efficient peroxidase mimic that was engineered by depositing Ir atoms as ultrathin skins (a few atomic layers) on Pd nanocubes (i.e., Pd-Ir cubes). The Pd-Ir cubes exhibited significantly enhanced efficiency, with catalytic constants more than 20- and 400-fold higher than those of the initial Pd cubes and horseradish peroxidase (HRP), respectively. As a proof-of-concept demonstration, the Pd-Ir cubes were applied to the colorimetric enzyme-linked immunosorbent assay (ELISA) of human prostate surface antigen (PSA) with a detection limit of 0.67 pg/mL, which is ∼110-fold lower than that of the conventional HRP-based ELISA using the same set of antibodies and the same procedure.

  7. Electronic Structure of the fcc Transition Metals Ir, Rh, Pt, and Pd

    DEFF Research Database (Denmark)

    Andersen, O. Krogh

    1970-01-01

    /atom)/Ry, respectively. Spin-orbit coupling is important for all four metals and the coupling parameter varies by 30% over the d bandwidth. Detailed comparisons with de Haas—van Alphen Fermi-surface dimensions have previously been presented and the agreement was very good. Comparison with measured electronic specific......We give a complete description of a relativistic augmented-plane-wave calculation of the band structures of the paramagnetic fcc transition metals Ir, Rh, Pt, and Pd. The width and position of the d band decrease in the sequence Ir, Pt, Rh, Pd; and N(EF)=13.8,23.2,18.7, and 32.7 (states...

  8. Template-engaged synthesis of RuSe 2 and Pd 17Se 15 nanotubes by reacting precursor salts with selenium nanowires

    Science.gov (United States)

    Jiang, Xuchuan; Mayers, Brian; Wang, Yuliang; Cattle, Bryan; Xia, Younan

    2004-02-01

    In the present work, nanowires of trigonal selenium ( t-Se) were reacted with Ru(acac) 3 and Pd(acac) 2 (or PdCl 2) to generate RuSe 2 and Pd 17Se 15 on the surface of each t-Se nanowire as a uniform, conformal sheath. The unreacted cores of selenium could be evaporated by heating the as-synthesized Se@RuSe 2 and Se@Pd 17Se 15 nanocables to yield selenide nanotubes with their typical wall-thickness around 6 nm. This template-engaged approach allowed for the production of both nanocables and nanotubes in a relatively large scale, and is believed to be able to get extended to synthesize other chalcogenides as tubular nanostructures.

  9. Production of ultrapure hydrogen in a Pd-Ag membrane reactor using Ru/La{sub 2}O{sub 3} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Faroldi, B.; Carrara, C.; Lombardo, E.A.; Cornaglia, L.M. [Instituto de Investigaciones en Catalisis y Petroquimica (FIQ, UNL-CONICET), Santiago del Estero, 2829-3000 Santa Fe (Argentina)

    2007-03-01

    Ru catalysts supported on lanthanum oxide with different loadings were prepared by wet impregnation. These solids were characterized by laser Raman spectroscopy (LSR), XPS, XRD and TPR. The catalytic activity toward hydrogen production through the dry reforming of methane was determined in a fixed-bed reactor and a membrane reactor. The reaction rate expressed per gram of Ru decreased when the metal loading increased. In the Pd-Ag membrane reactor, when the sweep gas flow rate (SG) increased, the conversions overcame the equilibrium values and the difference between CH{sub 4} and CO{sub 2} conversions decreased. Both Ru(0.6) and Ru(1.2) catalysts were able to restore the equilibrium for the dry reforming reaction up to values of SG = 30 ml min{sup -1}; Ru(0.6) was the most effective catalyst. By employing a CO{sub 2}/CH{sub 4} 1 and a SG of 0.05 mmol s{sup -1}, both a high H{sub 2} permeation flux of 5.68 x 10{sup -7} mol s{sup -1} m{sup -2} and a hydrogen recovery of 80% were obtained. Both the TPR and the Raman spectroscopy data indicated the presence of Ru(III) strongly interacting with La. Significantly, this observation was further confirmed by the appearance of Ru(III) on the surface. When the Ru content increased, the higher Ru 3d binding energy component was proposed as arising from Ru(IV). Concerning the Ru(1.2) solid, the presence of Ru(IV) was detected by means of TPR experiments, in agreement with the high proportion of Ru(IV) on the surface. Therefore, a fraction of Ru loading was present in this solid as species with weaker metal-support interaction leading to the slight deactivation of this catalyst in the membrane reactor. (author)

  10. [Determination of ru, rh and Pd in 30% trialkyl phosphine oxide (TRPO)-kerosene by inductively coupled plasma-atomic emission spectrum (ICP-AES)].

    Science.gov (United States)

    Wang, Jian-Chen; Zhang, Lin

    2013-07-01

    The determination method of Ru, Rh and Pd in 30% TRPO-kerosene ICP-AES was studied by using aqueous calibration reference solution and choosing ethanol as diluent. The effects of the contents of 30% TRPO-kerosene and aqueous solution and the concentration of HNO3 in 30% TRPO-kerosene on the intensities of Ru, Rh and Pd were described. The optimized condition for preparing samples and calibration solutions was chosen as follows: The contents of 30% TRPO-kerosene and aqueous phase were 10% (V/V) and 5% (V/V) respectively and the concentration of HNO3 30% TRPO-kerosene was 0.20 mol x L(-1). The determination method of Au, Ru and Pd was set up according to the above condition. The detection limit, precision and recovery ratio of Ru, Rh and Pd are well. The method is not only used in determination of Au, Ru and Pd in 30% TRPO-kerosene, but also used in other organic phases.

  11. Bifunctional electrodes with ir and Ru oxide mixtures and pt for unified regenerative cells; Electrodos bifuncionales basados en mezclas de oxidos de Ir y Ru con Pt para celdas regenerativas unificadas

    Energy Technology Data Exchange (ETDEWEB)

    Duron-Torres, S.M.; Escalante-Garcia, I.L. [Universidad Autonoma de Zacatecas, Zacatecas (Mexico); Cruz, J. C.; Arriaga-Hurtado; L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Pedro Escobedo, Queretaro (Mexico)]. E-mail: duronsm@prodigy.net.mx

    2009-09-15

    Unified regenerative fuel cells (URFC) represent an attractive option to obtain hydrogen and generate energy using a compact device. Nevertheless, the fusion of a fuel cell (PEMFC) and a water electrolyzer continue to be a challenge because of the wide range of conditions to which this type of device is subject. Because of its kinetic characteristics, oxygen reduction reaction (ORR) in PEMFC and oxygen evolution reaction (OER) in PEMWE are the limiting stages of the URFC depending on the mode of operation. The primary focus of research related to URFC is the obtainment of bifunctional electrocatalysts that satisfactorily perform in both oxygen reactions and support the different working conditions found in a fuel cell and an electrolyzer. The present work contributes to the research on bifunctional electrocatalysts and shows some preliminary results from the electrochemical study of different Pt gcc, IrO{sub 2} and RuO{sub 2} mixtures supported in Ebonex® as oxygen electrodes. The electrochemical characterization with cyclic voltamperometry (CV), linear voltamperometry (LV) and electrochemical impedance spectroscopy (EIS) in H{sub 2}SO{sub 4} 0.5 M, in the absence and present of oxygen shows that Ebonex®-supported bifunctional electrodes IrO{sub 2}-Pt and RuO{sub 2}-Pt present reasonable electrocatalytic properties for oxygen evolution and reduction reactions and present the possibility of their use in an URFC. The Ir- based oxide electrodes show greater stability than ruthenium-oxide electrodes. [Spanish] Las celdas de combustible regenerativas unificadas (URFC) representan una atractiva opcion para la obtencion de hidrogeno y generacion de energia en un dispositivo compacto. Sin embargo, la fusion de una celda de combustible (PEMFC) y un electrolizador de agua (PEMWE) sigue siendo un reto por la amplia gama de condiciones a que se sujeta un dispositivo de este tipo. Por sus caracteristicas cineticas, la reaccion de reduccion de oxigeno (ORR) en la PEMFC y la

  12. Relationship between element-selective electronic states and hydrogen absorption properties of Pd-M (M =Ru ,Rh,Ag, and Au) alloys

    Science.gov (United States)

    Fujii, Kanako; Ishimatsu, Naoki; Maruyama, Hiroshi; Shishidou, Tatsuya; Hayakawa, Shinjiro; Kawamura, Naomi

    2017-01-01

    To understand how the constituent atoms participate in the hydrogenation of Pd-based alloys at ˜0.1 MPa of hydrogen pressure (PH2),we investigated the electronic states in Pd-M (M =Ru,Rh,Ag, and Au) alloys and their hydrides element-selectively by using x-ray absorption spectroscopy at the L2 ,3 edges. Spectral changes near the absorption edge demonstrate that both Pd and M atoms form bonds with H atoms in the Pd-M (M =Ru and Rh) alloys even at PH 2˜0.1 MPa. This is a striking result because high pressures of more than 1 GPa are required for the hydrogenation of Rh and Ru pure metals. In contrast, only Pd atoms bond with H atoms and the M -H bond is absent in the case of Pd-M (M =Ag and Au) alloys. Therefore, the hydrogen-induced changes in the electronic states differ between M s with fully occupied d shells and M s with partially occupied d shells. This study reveals that the thermodynamic hydrogenation properties of Pd-M alloys can be determined by a combination of the formation of the M -H bond and lattice expansion or compression by alloying Pd metal with M .

  13. Impedance and Stability of M/CGO (M: Ni, Pd, Ru) Co-infiltrated Nb-doped SrTiO3 SOFC Anodes

    DEFF Research Database (Denmark)

    Ramos, Tania; Veltzé, Sune; Reddy Sudireddy, Bhaskar;

    2014-01-01

    at 850°C, 50% H2O/H2 decreased in the order Ni/CGO≫Pd/CGO > Ru/CGO. After 200h of exposure Ru/CGO not only continued to exhibit low impedance, with final total Rp ≅ 0.02 Ωcm2, but also negligible degradation. For comparison, Ni/CGO degraded close to a factor of 3 to ca. 0.25 Ωcm2 in an equivalent period...

  14. Effect of pressure on the Curie temperature of Mn{sub 2}RuSn and Mn{sub 2}PdSn

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Y., E-mail: adachy@yz.yamagata-u.ac.jp [Graduate School of Science and Engineering, Yamagata University, Yonezawa 992-8510 (Japan); Watanabe, T. [Faculty of Engineering, Yamagata University, Yonezawa 992-8510 (Japan); Kanomata, T. [Faculty of Engineering, Tohoku Gakuin University, Tagajo 985-8537 (Japan); Research Institute for Engineering and Technology, Tohoku Gakuin University, 985-8537 (Japan); Hayasaka, M.; Endo, K. [Faculty of Engineering, Tohoku Gakuin University, Tagajo 985-8537 (Japan); Nishihara, H. [Faculty of Science and Technology, Ryukoku University, Otsu 520-2194 (Japan); Xu, X.; Kainuma, R. [Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan)

    2017-04-15

    Effect of pressure on the Curie temperature T{sub C} of the Mn-rich Heusler alloys Mn{sub 2}RuSn and Mn{sub 2}PdSn has been investigated by measuring the temperature dependence of initial permeability at various pressures up to 10 kbar. It was found that the Curie temperatures of Mn{sub 2}RuSn and Mn{sub 2}PdSn decrease with increasing pressure. The pressure derivatives of T{sub C} were estimated to be −0.59 K/kbar for Mn{sub 2}RuSn and −0.80 K/kbar for Mn{sub 2}PdSn. On the basis of the experimental results, the relationship between the magnetic transition temperature and the Mn-Mn distance is discussed.

  15. A general approach for the synthesis of bimetallic M–Sn (M = Ru, Rh and Ir) catalysts for efficient hydrogenolysis of ester

    KAUST Repository

    Samal, Akshaya K.

    2016-11-24

    A versatile synthetic method was applied for the preparation of Sn containing bimetallic catalysts. The synthesis was performed by simply mixing the super hydride [LiB(C2H5)(3)H], with a metal (Ru, Rh or Ir) salt and an organotin complex in tetrahydrofuran solvent without using any surfactant. This leads to the formation of monodispersed M-Sn (M = Ru, Rh or Ir) bimetallic nanoparticles (NPs). These bimetallic catalysts show high performances in the hydrogenolysis of ester to the corresponding alcohol.

  16. Pt, Au, Pd and Ru Partitioning Between Mineral and Silicate Melts: The Role of Metal Nanonuggets

    Science.gov (United States)

    Malavergne, V.; Charon, E.; Jones, J.; Agranier, A.; Campbell, A.

    2012-01-01

    , Ru and Pd in minerals (olivine and diopside) and in silicate melts, but also to characterize the sizes, density and chemistry of HSE nuggets when present in the samples.

  17. Exploring Pd adsorption, diffusion, permeation, and nucleation on bilayer SiO2/Ru as a function of hydroxylation and precursor environment: From UHV to catalyst preparation

    Science.gov (United States)

    Pomp, Sascha; Kaden, William E.; Sterrer, Martin; Freund, Hans-Joachim

    2016-10-01

    The hydroxylation-dependent permeability of bilayer SiO2 supported on Ru(0001) was investigated by XPS and TDS studies in a temperature range of 100 K to 600 K. For this, the thermal behavior of Pd evaporated at 100 K, which results in surface and sub-surface (Ru-supported) binding arrangements, was examined relative to the extent of pre-hydroxylation. Samples containing only defect-mediated hydroxyls showed no effect on Pd diffusion through the film at low temperature. If, instead, the concentration of strongly bound hydroxyl groups and associated weakly bound water molecules was enriched by an electron-assisted hydroxylation procedure, the probability for Pd diffusion through the film is decreased via a pore-blocking mechanism. Above room temperature, all samples showed similar behavior, reflective of particle nucleation above the film and eventual agglomeration with any metal atoms initially binding beneath the film. When depositing Pd onto the same SiO2/Ru model support via adsorption of [Pd(NH3)4]Cl2 from alkaline (pH 12) precursor solution, we observe notably different adsorption and nucleation mechanisms. The resultant Pd adsorption complexes follow established decomposition pathways to produce model catalyst systems compatible with those created exclusively within UHV despite lacking the ability to penetrate the film due to the increased size of the initial Pd precursor groups.

  18. IrPd nanoalloys: simulations, from surface segregation to local electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Andriamiharintsoa, T. H. [Institut de Physique et Chimie des Matériaux de Strasbourg CNRS-UDS UMR 7504 (France); Rakotomahevitra, A. [Institut pour la Maîtrise de l’Énergie, Faculté des sciences d’Antananarivo (Madagascar); Piccolo, L. [Institut de Recherches sur la Catalyse et l’Environnement de Lyon IRCELYON, UMR 5256 CNRS and Université Lyon 1 (France); Goyhenex, C., E-mail: christine.goyhenex@ipcms.unistra.fr [Institut de Physique et Chimie des Matériaux de Strasbourg CNRS-UDS UMR 7504 (France)

    2015-05-15

    Using semi-empirical modeling, namely tight-binding at different levels of accuracy, the chemical, crystallographic, and electronic structures of bimetallic IrPd nanoparticles are characterized. For the purpose, model cuboctahedral particles containing 561 atoms are considered. Atomistic simulations show that core–shell nanoparticles are highly stable, with a strong surface segregation of Pd, at least for one atomic shell thickness. Within self-consistent tight-binding calculations founded on the density functional theory, an accurate insight is given into the electronic structure of these materials which have a high potential as catalysts.

  19. Remarkable activity of PdIr nanoparticles supported on the surface of carbon nanotubes pretreated via a sonochemical process for formic acid electro-oxidation

    Science.gov (United States)

    Chen, Jinwei; Li, Yuanjie; Liu, Shuangren; Wang, Gang; Tian, Jing; Jiang, Chunping; Zhu, Shifu; Wang, Ruilin

    2013-12-01

    It was reported for the first time that the surface treated multi-walled carbon nanotubes supported PdIr (PdIr/CNT-SCP) catalyst presents remarkable electrocatalytic activity and stability for formic acid electro-oxidation (FAEO). The surface of CNTs was functionalized by a sonochemical process for the deposition of PdIr nanoparticles (NPs). The XRD and TEM characterizations show that the prepared PdIr/CNT-SCP catalyst has small mean size and good dispersion of PdIr NPs on CNTs. The electrochemical measurements show that the onset and anodic peak potentials of FAEO on PdIr/CNT-SCP catalyst are 60 and 50 mV more negative than that on the commercial Pd/C catalyst. The mass-normalized peak current density of PdIr/CNT-SCP is 3365 mA mg-1Pd, which is 4.5, 1.4 and 2.7 times higher than that of PdIr/CNT-Untreated, PdIr/C-SCP and commercial Pd/C, respectively. It demonstrates the promotion of Ir and functionalized CNTs to Pd for FAEO.

  20. Interface-driven topological Hall effect in SrRuO3-SrIrO3 bilayer.

    Science.gov (United States)

    Matsuno, Jobu; Ogawa, Naoki; Yasuda, Kenji; Kagawa, Fumitaka; Koshibae, Wataru; Nagaosa, Naoto; Tokura, Yoshinori; Kawasaki, Masashi

    2016-07-01

    Electron transport coupled with magnetism has attracted attention over the years. Among them, recently discovered is topological Hall effect (THE), originating from scalar spin chirality, that is, the solid angle subtended by the spins. THE is found to be a promising tool for probing the Dzyaloshinskii-Moriya (DM) interaction and consequent magnetic skyrmions. This interaction arises from broken inversion symmetry and hence can be artificially introduced at interface; this concept is lately verified in metal multilayers. However, there are few attempts to investigate such DM interaction at interface through electron transport. We clarified how the transport properties couple with interface DM interaction by fabricating the epitaxial oxide interface. We observed THE in epitaxial bilayers consisting of ferromagnetic SrRuO3 and paramagnetic SrIrO3 over a wide region of both temperature and magnetic field. The magnitude of THE rapidly decreases with the thickness of SrRuO3, suggesting that the interface DM interaction plays a significant role. Such interaction is expected to realize a 10-nm-sized Néel-type magnetic skyrmion. The present results established that the high-quality oxide interface enables us to tune the effective DM interaction; this can be a step toward future topological electronics.

  1. Strong anisotropy within a Heisenberg model in the Jeff=1/2 insulating state of Sr2Ir0.8Ru0.2O4

    Science.gov (United States)

    Calder, S.; Kim, J. W.; Taylor, A. E.; Upton, M. H.; Casa, D.; Cao, Guixin; Mandrus, D.; Lumsden, M. D.; Christianson, A. D.

    2016-12-01

    The dispersive magnetic excitations in Sr2IrO4 have previously been well described within an isospin-1/2 Heisenberg model on a square lattice that revealed parallels with La2CuO4 . Here we investigate the inelastic spectra of Sr2Ir0.8Ru0.2O4 with resonant inelastic x-ray scattering (RIXS) at the Ir L3 edge. The results are well described using linear spin-wave theory within a similar Heisenberg model applicable to Sr2IrO4 ; however, the disorder induced by the substitution of 20 %Ir4 + ions for Ru4 + removes longer range exchange interactions. A large spin gap (40 meV) is measured indicating strong anisotropy from spin-orbit coupling that is manifest due to the altered magnetic structure in Sr2Ir0.8Ru0.2O4 with c -axis aligned moments compared to the basal plane moments in the parent. Collectively the results indicate the robustness of a Heisenberg model description even when the magnetic structure is altered and the Jeff=1 /2 moments are diluted.

  2. Ru-assisted synthesis of {111}-faceted Pd truncated bipyramids: a highly reactive, stable and restorable catalyst for formic acid oxidation.

    Science.gov (United States)

    Wu, Dongshuang; Cao, Minna; Cao, Rong

    2014-11-04

    {111}-Faceted Pd truncated triangular bipyramids (TTBPs) are first presented under the assistance of Ru. Attributed to their unique shape, the TTBPs are highly active and stable for formic acid oxidation. The electrochemical active surface area (ECSA) can be restored to its initial value after a harsh degradation test.

  3. Epitaxial Growth of Multimetallic Pd@PtM (M = Ni, Rh, Ru) Core-Shell Nanoplates Realized by in Situ-Produced CO from Interfacial Catalytic Reactions.

    Science.gov (United States)

    Yan, Yucong; Shan, Hao; Li, Ge; Xiao, Fan; Jiang, Yingying; Yan, Youyi; Jin, Chuanhong; Zhang, Hui; Wu, Jianbo; Yang, Deren

    2016-12-14

    Pt-based multimetallic core-shell nanoplates have received great attention as advanced catalysts, but the synthesis is still challenging. Here we report the synthesis of multimetallic Pd@PtM (M = Ni, Rh, Ru) nanoplates including Pd@Pt nanoplates, in which Pt or Pt alloy shells with controlled thickness epitaxially grow on plate-like Pd seeds. The key to achieve high-quality Pt-based multimetallic nanoplates is in situ generation of CO through interfacial catalytic reactions associated with Pd nanoplates and benzyl alcohol. In addition, the accurate control in a trace amount of CO is also of great importance for conformal growth of multimetallic core-shell nanoplates. The Pd@PtNi nanoplates exhibit substantially improved activity and stability for methanol oxidation reaction (MOR) compared to the Pd@Pt nanoplates and commercial Pt catalysts due to the advantages arising from plate-like, core-shell, and alloy structures.

  4. Adsorption and decomposition of monopropellant molecule HAN on Pd(100) and Ir(100) surfaces: A DFT study

    Science.gov (United States)

    Banerjee, Sourav; Shetty, Sharath A.; Gowrav, M. N.; Oommen, Charlie; Bhattacharya, Atanu

    2016-11-01

    We have performed density functional theory calculations with the generalized gradient approximation to investigate the catalytic decomposition reactions of one of the most promising monopropellants, hydroxylammonium nitrate (HAN), on two catalytically active single crystal Pd(100) and Ir(100) surfaces, aiming at exploring different reaction pathways and reactivities of these two surfaces towards the catalytic decomposition of HAN. We find that the HAN molecule binds both the Pd(100) and Ir(100) surfaces molecularly in different orientations with respect to the surface. The HONO elimination is found to possess the lowest activation energy on the Pd(100) surface; whereas, NO2 elimination is predicted to show the lowest activation energy on the Ir(100) surface. Exothermicities associated with different reaction steps are also discussed. This is the first theoretical report on the catalytic decomposition reactions of the HAN molecule on the single crystal Pd(100) and the Ir(100) surfaces using the periodic DFT calculations.

  5. 'Click' generated 1,2,3-triazole based organosulfur/selenium ligands and their Pd(ii) and Ru(ii) complexes: their synthesis, structure and catalytic applications.

    Science.gov (United States)

    Kumar, Satyendra; Saleem, Fariha; Singh, Ajai K

    2016-07-28

    1-(2,6-Diisopropylphenyl)-4-(phenylthio/selenomethyl)-1H-1,2,3-triazole (L1/L2) was synthesized by a 'Click' reaction and treated with [Pd(CH3CN)2Cl2] for 5 h or [(η(6)-C6H6)RuCl(μ-Cl)]2 for 8 h (followed by reaction with NH4PF6) at room temperature, resulting in complexes [Pd(L)Cl2] (1 and 2) or [(η(6)-C6H6)Ru(L)Cl]PF6 (3 and 4) (L = L1 or L2), respectively. The four complexes (1-4) and ligands (L1 and L2) were characterized with (1)H, (13)C{(1)H} and (77)Se{(1)H} NMR spectroscopy and high resolution mass spectrometry. The single crystal structures of 1-4 were solved. The geometry of Pd in 1 and 2 is distorted square planar. The Pd-S and Pd-Se bond distances in 1 and 2 are 2.277(3) and 2.384(6) Å respectively. In 3 and 4, there is a pseudo-octahedral "piano-stool" type disposition of donor atoms around Ru. The Ru-S and Ru-Se bond lengths in 3 and 4 are 2.3728(12) and 2.4741(6) Å respectively. The catalytic activity of complexes 1 and 2 was explored for Suzuki-Miyaura coupling (SMC) in water and the Sonogashira coupling reaction. For various aryl bromides, including deactivated ones, complexes 1 and 2 were found to be efficient catalysts for both couplings. The optimum loading of 1 and 2 required to catalyze both coupling reactions is of the order of 0.001-2 mol% of Pd. For SMC, no additive or phase transfer catalyst was added. For catalysis of the transfer hydrogenation (TH) of aldehydes and ketones, the half-sandwich Ru(ii) complexes 3 and 4 were explored. Their optimum catalytic loading was found to be 0.1-0.4 mol% of Ru. For TH, both the water solvent and the glycerol hydrogen source are environmentally friendly. The catalytic efficiencies of 3 and 4 are comparable with those reported for other catalysts for TH carried out with 2-propanol or glycerol as a H-source. 1, with a sulfur ligand, is more efficient than 2 (Se analog) for both SMC and the Sonogashira coupling. The activities of 3 and 4 for TH are in the order Se > S.

  6. Structural and chelation behaviors of new Ru(II), Pt(IV) and Ir(III) gatifloxacin drug complexes: Spectroscopic characterizations

    Science.gov (United States)

    Alghamdi, Mohammed T.; Alsibaai, A. A.; El-Shahawi, M. S.; Refat, Moamen S.

    2017-02-01

    The interaction between gatifloxacin drug (GAT) with some transition metals (Ru(III), Pt(IV) and Ir(III)) yield the complexes of formulas [Ru(GAT-NH4)(Cl)3(H2O)2], [Pt(GAT-NH4)2(Cl)4]·3H2O and [Ir(GAT-NH4)2(Cl)2(H2O)2]·Cl·2H2O at pH = 7-8. The composition of the GAT complexes was confirmed by elemental data. The IR frequencies reveal the coordination of the GAT with metal ions and the coordination mode of the sbnd N atom of 3-methylpiperazinyl moiety to metal. XRD pattern show isomorphism among the complexes with similar chelation behavior. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used to identify the particle size of GAT complexes. The thermal data reveals that various steps of decomposition of the complexes to form their metal oxide as final product. The electronic spectra and the magnetic susceptibility values reveal that the coordination and geometry of Ru3+, Pt4+ and Ir3+ complexes possess distorted octahedral geometry with six number of coordination. Thermodynamic parameters (E*, ΔS*, ΔH* and ΔG*) were calculated from TG curves dependent on Coats-Redfern and Horowitz-Metzeger non-isothermal methods.

  7. Graphene decorated with Pd4Ir nanocrystals: Ultrasound-assisted synthesis, and application as a catalyst for oxidation of formic acid.

    Science.gov (United States)

    Zhang, Lian Ying; Liu, Ze

    2017-11-01

    An effective strategy of ultrasmall and surface-clean Pd4Ir nanocrystals uniformly decorated on graphene was developed using ultrasnoic-assisted approach. The prepared Us-Pd4Ir@Graphene reduces Pd loading while holds much higher catalytic activity and better stability toward formic acid oxidation than that of commercial Pd-C, offering great promise as a superior anode catalyst for direct formic acid fuel cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Spin-Glass-Like Behavior and Topological Hall Effect in SrRuO3/SrIrO3 Superlattices for Oxide Spintronics Applications.

    Science.gov (United States)

    Pang, Bin; Zhang, Lunyong; Chen, Y B; Zhou, Jian; Yao, Shuhua; Zhang, Shantao; Chen, Yanfeng

    2017-01-25

    The heterostructure interface provides a powerful platform for exploring rich emergent phenomena, such as interfacial superconductivity and nontrivial topological surface states. Here, SrRuO3/SrIrO3 superlattices were epitaxially synthesized. The magnetic and magneto-transport properties of these superlattices were characterized. A broad cusp-type splitting in the zero-field-cooling/field-cooling temperature-dependent magnetization and magnetization relaxation, which follows the modified stretched function model, accompanied by double hysteresis magnetization loops were demonstrated. These physical effects were modulated by the SrIrO3 layer thickness, which confirms the coexistence of interfacial spin glass and ferromagnetic ordering in the superlattices. In addition, the topological Hall effect was observed at low temperatures, and it is weakened with the increase of the SrIrO3 layer thickness. These results suggest that a noncoplanar spin texture is generated at the SrRuO3/SrIrO3 interfaces because of the interfacial Dzyaloshinskii-Moriya interaction. This work demonstrates that SrIrO3 can effectively induce interfacial Dzyaloshinskii-Moriya interactions in superlattices, which would serve as a mechanism to develop spintronic devices with perovskite oxides.

  9. Large exchange bias enhancement in (Pt(or Pd)/Co)/IrMn/Co trilayers with ultrathin IrMn thanks to interfacial Cu dusting

    Energy Technology Data Exchange (ETDEWEB)

    Vinai, G. [SPINTEC, UMR 8191 CEA/CNRS/UJF/Grenoble-INP, CEA/INAC, 17, rue des Martyrs, 38054 Grenoble (France); Crocus Technology, 4 Place Robert Schuman, 38054 Grenoble (France); Moritz, J. [Institut Jean Lamour, UMR 7198 CNRS - Université de Lorraine, Bd des Aiguillettes, BP 70239, F-54506 Vandoeuvre-les-Nancy Cedex (France); Bandiera, S. [Crocus Technology, 4 Place Robert Schuman, 38054 Grenoble (France); Prejbeanu, I. L.; Dieny, B. [SPINTEC, UMR 8191 CEA/CNRS/UJF/Grenoble-INP, CEA/INAC, 17, rue des Martyrs, 38054 Grenoble (France)

    2014-04-21

    The magnitude of exchange bias (H{sub ex}) at room temperature can be significantly enhanced in IrMn/Co and (Pt(or Pd)/Co)/IrMn/Co structures thanks to the insertion of an ultrathin Cu dusting layer at the IrMn/Co interface. The combination of trilayer structure and interfacial Cu dusting leads to a three-fold increase in H{sub ex} as compared to the conventional IrMn/Co bilayer structure, with an increased blocking temperature (T{sub B}) and a concave curvature of the temperature dependence H{sub ex}(T), ideal for improved Thermally Assisted-Magnetic Random Access Memory storage layer. This exchange bias enhancement is ascribed to a reduction of the spin frustration at the IrMn/Co interface thanks to interfacial Cu addition.

  10. Catalytic activity and mechanistic approach of NO reduction by CO over M0.05Co2.95O4 (M = Rh, Pd & Ru) spinel system

    Science.gov (United States)

    Salker, A. V.; Desai, M. S. Fal

    2016-12-01

    Pd, Rh and Ru doped cobalt oxide spinels have been prepared by citric acid assisted sol-gel method to yield nano-catalysts. Compositions have been characterized by XRD, FTIR, TG/DTA, BET, SEM, TEM, TPD and XPS techniques. Simultaneous catalytic detoxification of nitric oxide and carbon monoxide is investigated over the doped and pristine catalysts. Metal doping is found to enhance the activity of the catalysts due to their better adsorption capacity. Moisture and oxygen tolerance is investigated for Rh and Pd substituted catalysts. A probable reaction mechanism on the catalyst surface has been proposed.

  11. Catalytic mechanisms of direct pyrrole synthesis via dehydrogenative coupling mediated by PNP-Ir or PNN-Ru pincer complexes: Crucial role of proton-transfer shuttles in the PNP-Ir system

    KAUST Repository

    Qu, Shuanglin

    2014-04-02

    Kempe et al. and Milstein et al. have recently advanced the dehydrogenative coupling methodology to synthesize pyrroles from secondary alcohols (e.g., 3) and β-amino alcohols (e.g., 4), using PNP-Ir (1) and PNN-Ru (2) pincer complexes, respectively. We herein present a DFT study to characterize the catalytic mechanism of these reactions. After precatalyst activation to give active 1A/2A, the transformation proceeds via four stages: 1A/2A-catalyzed alcohol (3) dehydrogenation to give ketone (11), base-facilitated C-N coupling of 11 and 4 to form an imine-alcohol intermediate (18), base-promoted cyclization of 18, and catalyst regeneration via H2 release from 1R/2R. For alcohol dehydrogenations, the bifunctional double hydrogen-transfer pathway is more favorable than that via β-hydride elimination. Generally, proton-transfer (H-transfer) shuttles facilitate various H-transfer processes in both systems. Notwithstanding, H-transfer shuttles play a much more crucial role in the PNP-Ir system than in the PNN-Ru system. Without H-transfer shuttles, the key barriers up to 45.9 kcal/mol in PNP-Ir system are too high to be accessible, while the corresponding barriers (<32.0 kcal/mol) in PNN-Ru system are not unreachable. Another significant difference between the two systems is that the addition of alcohol to 1A giving an alkoxo complex is endergonic by 8.1 kcal/mol, whereas the addition to 2A is exergonic by 8.9 kcal/mol. The thermodynamic difference could be the main reason for PNP-Ir system requiring lower catalyst loading than the PNN-Ru system. We discuss how the differences are resulted in terms of electronic and geometric structures of the catalysts and how to use the features in catalyst development. © 2014 American Chemical Society.

  12. Degradation mechanism of Methyl Orange by electrochemical process on RuO(x)-PdO/Ti electrode.

    Science.gov (United States)

    Du, Lin; Wu, Jin; Qin, Song; Hu, Changwei

    2011-01-01

    The electrochemical degradation of Methyl Orange in 0.1 M NaCl solution over RuO(x)-PdO/Ti anode was investigated. Chemical oxygen demand (COD), ion chromatography (IC), Fourier Transform Infrared Spectroscopy (FTIR) and Gas chromatography-mass spectrometry (GC-MS) were employed to detect the intermediates formed during the electrochemical degradation. In the present reaction system, Methyl Orange could be effectively degraded. After 1 h treatment, the discoloration could reach 97.9% with COD removal of 57.6%. The results indicated that in the presence of chloride, the electrolysis was able to oxidise the dye with partial mineralisation of carbon, nitrogen and sulfur into CO(2), NO(-)(3) and SO(2-)(4), respectively. After 8 h electrolysis, 62% of sulfur contained in Methyl Orange was transformed to SO(4)(2-), and 17.6% of nitrogen changed to NO(3)(-). The intermediates during electroprocess were detected to be low molecular weight compounds, chlorinated compounds, derivatives of benzene and long chain alkanes. Based on these data, a possible degradation mechanism of Methyl Orange was proposed.

  13. Electrochemical characterization of IrO{sub 2}-Pt and RuO{sub 2}-Pt mixtures as bifunctional electrodes for unitized regenerative fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Escalante-Garcia, I.L.; Duron-Torres, S.M. [Univ. Autonoma de Zacatecas, Zacatecas (Mexico). Unidad Academica de Ciencias Quimicas; Cruz, J.C.; Arriaga-Hurtado, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Pedro Escobedo (Mexico)

    2010-07-15

    A unitized regenerative fuel cell (URFC) is a single electrochemical cell that has the potential to meet the required features of an idealized energy cycle whereby hydrogen can be produced from renewable energy sources. A URFC is a system which can operate as a polymer electrolyte water electrolyzer (PEMWE) or as a polymer electrolyte fuel cell (PEMFC). In the PEMWE mode, water is converted into hydrogen and oxygen by using electricity from solar or wind energy. In the PEMFC mode, the stored hydrogen and oxygen are supplied to generate electricity and water. Combining PEMWEs and PEMFCs remains a great challenge because several practical and structural features must be considered. The limiting reaction steps at the oxygen electrode for PEMFC or PEMWE are the oxygen reduction reaction (ORR) and the water oxidation reaction (OER), respectively. The high-efficiency therefore depends on the type of electrocatalysts and the capability of the oxygen electrode to operate under PEMFC or PEMWE conditions. As such, much research has gone into the development of a new oxygen electrode design for URFCs. Several bifunctional electrodes for OER and ORR were designed in this study using platinum (Pt) and iridium oxide (IrO{sub 2}) electrocatalysts or Pt and ruthenium oxide (RuO{sub 2}) supported electrocatalysts on Ebonex{sup R}. According to electrochemical characterization by CV, LV and EIS in aqueous 0.5 M H{sub 2}SO{sub 4}, IrO{sub 2}-Pt and RuO{sub 2}-Pt supported on Ebonex have high electrocatalytic properties for ORR and OER, indicating potential use in URFCs. IrO{sub 2} based electrodes were more stable than RuO{sub 2} based electrodes. 31 refs., 2 tabs., 6 figs.

  14. New neutron diffraction results on magnetic properties of the cubic rare earth compounds HoP and PrX/sub 2/ (X = Ru, Rh, Ir, Pt)

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, P.; Haelg, W.; Kaldis, E.; Greidanus, F.J.A.M.; Buschow, K.H.J.

    1982-01-01

    Neutron diffraction studies performed on polycrystalline, NaCl type HoP in external magnetic fields yield <100> as easy directions of magnetization in the ferromagnetic state. The magnetic ordering of the MgCu/sub 2/ type Laves phase systems PrX/sub 2/ (X = Ru, Rh, Ir, Pt) was investigated on powdered samples by means of neutron diffraction. Simple ferromagnetic structures were observed. The determined Curie temperatures confirm bulk measurements, and the values of the ordered magnetic moments indicate crystal field effects.

  15. New neutron diffraction results on magnetic properties of the cubic rare earth compounds HoP and PrX2 (X=Ru, Rh, Ir, Pt)

    Science.gov (United States)

    Fischer, P.; Hälg, W.; Kaldis, E.; Greidanus, F. J. A. M.; Buschow, K. H. J.

    1982-09-01

    Neutron diffraction studies performed on polycrystalline, NaCl type HoP in external magnetic fields yield as easy directions of magnetization in the ferromagnetic state. The magnetic ordering of the MgCu2 type Laves phase systems PrX2 (X=Ru, Rh, Ir, Pt) was investigated on powdered samples by means of neutron diffraction. Simple ferromagnetic structures were observed. The determined Curie temperatures confirm bulk measurements, and the values of the ordered magnetic moments indicate crystal field effects.

  16. Self-enhanced N-(aminobutyl)-N-(ethylisoluminol) derivative-based electrochemiluminescence immunosensor for sensitive laminin detection using PdIr cubes as a mimic peroxidase

    Science.gov (United States)

    Jiang, Xinya; Wang, Huijun; Wang, Haijun; Zhuo, Ying; Yuan, Ruo; Chai, Yaqin

    2016-04-01

    Herein, a self-enhanced N-(aminobutyl)-N-(ethylisoluminol) (ABEI) derivative-based electrochemiluminescence (ECL) immunosensor was constructed for the determination of laminin (LN) using PdIr cubes as a mimic peroxidase for signal amplification. Initially, PdIr cubes with efficient peroxidase mimicking properties, large specific surface areas, and good stability and uniformity were synthesized. Then, l-cysteine (l-Cys) and ABEI were immobilized on the PdIr cubes to form the self-enhanced ECL nanocomplex (PdIr-l-Cys-ABEI). In this nanocomplex, PdIr cubes, whose catalytic constant is higher than that of horseradish peroxidase (HRP), could effectively catalyze H2O2 decomposition and thus enhance the ECL intensity of ABEI. Moreover, PdIr cubes can be easily modified with functional groups, which make them adaptable to desired supported platforms. On the other hand, l-Cys as a coreactant of ABEI could effectively enhance the luminous efficiency due to the intramolecular ECL reaction which could reduce the energy loss between l-Cys and ABEI by giving a shorter electron transfer distance. The developed strategy combined an ABEI derivative as a self-enhanced ECL luminophore and PdIr cubes as a mimic peroxidase, resulting in a significantly enhanced ECL signal output. Also, the strategy showed high sensitivity and selectivity for LN, which suggested that our new approach could be potentially applied in monitoring different proteins.

  17. Role of vacancies in the relaxation of Pd-5.3 at % In-0.5 at % Ru alloy foil after hydrogen desorption

    Science.gov (United States)

    Akimova, O. V.; Avdyukhina, V. M.; Shchetinin, I. V.

    2016-02-01

    The Pd-5.3 at % In-0.5 at % Ru foil subjected to electrolytic hydrogenation and subsequent prolonged relaxation (for 55 000 h) has been studied by X-ray diffraction analysis. Diffraction reflections belonging to phases with different indium concentrations and palladium phases enriched in vacancies were found. Phase transformations observed in the absence of hydrogen occur mainly due to the vacancy migration; the vacancies formed during hydrogenation and remained in vacancy complexes and alloy matrix up to the moment of the study.

  18. Pt{sub X}Ru{sub Y}Ir{sub Z} as a bifunctional electrocatalyst for oxygen reduction reaction in a PEM fuel cell; Pt{sub X}Ru{sub Y}Ir{sub Z} como electrocatalizador bifuncional para la reaccion redox del oxigeno en una celda tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Morales, L.; Fernandez, A.M. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Temixco, Morelos (Mexico)]. E-mail: limos@cie.unam.mx; Cano, U. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2009-09-15

    This work presents the synthesis and characterization of the ternary material Pt{sub X}Ru{sub Y}Ir{sub Z}, obtained by chemical reduction with NaBH{sub 4}. Two different atomic compositions were developed (sample A and B) in order to observe the kinetic effect, as suggested by the combinatorial libraries. The main objective of this synthesis is to study the oxygen reduction reaction (ORR and OER) and its potential use in the construction of a bifunctional catalyst. In addition, each of the metals are synthesized separately using the same technique in order to make the corresponding comparison. The compounds obtained were characterized by sweep electron microscopy, x-ray diffraction and composition using fluorescence and energy-dispersive x-ray spectroscopy. The results showed a displacement of the x-ray diffraction peaks for Ir and Pt in sample A, and displacement in sample B for Ru and Ir peaks. These changes suggest the possible formation of a solid solution substitution. Separate cyclic and linear voltamperometry studies were performed for the oxygen reduction and release reactions. The electrochemical analysis showed improved kinetic behavior when combining the three metals according to the composition of sample B. [Spanish] En este trabajo se presenta la sintesis y caracterizacion del material ternario Pt{sub X}Ru{sub Y}Ir{sub Z}, elaborado por la tecnica de Reduccion Quimica utilizando al NaBH{sub 4}. Se elaboraron dos composiciones atomicas diferentes (Muestra A y B) con el fin de observar el efecto cinetico, como lo sugieren las librerias combinatorias. El objetivo principal de esta sintesis es para el estudio de la Reaccion Redox del Oxigeno (RRO y REO) y su potencial uso para la construccion de un catalizador bifuncional. Asi mismo, se realiza la sintesis de cada uno de los metales por separado empleando la misma tecnica, con el proposito de realizar la comparacion correspondiente. Los compuestos obtenidos se caracterizaron por Microscopia Electronica de

  19. Specific heat, differential susceptibility and electrical resistivity of PrX2 (X = Ir, Pt, Rh and Ru) laves phase compounds at temperatures 1.4 K < T < 40 K

    Science.gov (United States)

    van Dongen, J. C. M.; van der Linden, H. W. M.; Greidanus, F. J. A. M.; Nieuwenhuys, G. J.; Mydosh, J. A.; Buschow, K. H. J.

    1980-01-01

    Specific heat and differential susceptibility data of PrX 2 (X = Ir, Pt, Rh, and Ru) compounds reveal phase transitions at Tc = (11.2 ± 0.5) K, (7.7 ± 0.5) K, (7.9 ± 0.5) K and (33.9 ± 0.5) K for X = Ir, Pt, RhandRu, resp. The electrical resistivity drops markedly below Tc, and the dϱ/d T versus T curve is similar to that of the specific heat.

  20. Electronic and magnetic transitions in perovskite SrRu{sub 1-x}Ir{sub x}O{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Abhijit; Lee, Yong Woo; Jeong, Yoon Hee, E-mail: yhj@postech.ac.kr [Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of)

    2015-09-07

    We have investigated the electronic and magnetic properties of perovskite SrRu{sub 1−x}Ir{sub x}O{sub 3} (0.0≤ x ≤ 0.25) thin films grown by pulsed laser deposition on atomically flat (001) SrTiO{sub 3} substrates. SrRuO{sub 3} has the properties of a ferromagnetic metal (resistivity ρ ∼ 200 μΩ · cm at T = 300 K) with Curie temperature T{sub C} ∼ 150 K. Substituting Ir (5d{sup 5+}) for Ru (4d{sup 4+}) in SrRuO{sub 3}, films (0.0 ≤ x ≤ 0.20) showed fully metallic behavior and ferromagnetic ordering, although ρ increased and the ferromagnetic T{sub C} decreased. Films with x = 0.25 underwent the metal-to-insulator transition (T{sub MIT}∼75 K) in ρ, and spin-glass-like ordering (T{sub SG}∼45 K) with the elimination of ferromagnetic long-range ordering caused by the electron localization at the substitution sites. In ferromagnetic films (0.0 ≤ x ≤ 0.20), ρ increased near-linearly with T at T > T{sub C}, but in paramagnetic film (x = 0.25) ρ increased as T{sup 3/2} at T > T{sub MIT}. Moreover, observed spin-glass-like (T{sub SG}) ordering with the negative magnetoresistance at T < T{sub MIT} in film with x = 0.25 validates the hypothesis that (Anderson) localization favors glassy ordering at amply disorder limit. These observations provide a promising approach for future applications and of fundamental interest in 4d and 5d mixed perovskites.

  1. Kinetic and mechanistic investigations of chlorocomplex of Ru(III and Ir(III catalyzed oxidation of d-fructose by N-bromophthalimide in acidic medium

    Directory of Open Access Journals (Sweden)

    Neerja Sachdev

    2016-09-01

    Full Text Available The kinetic and mechanistic studies of Ru(III and Ir(III homogeneously catalyzed oxidation of d-fructose (d-fru by N-bromophthalimide (NBP in the presence of aqueous perchloric acid medium have been made at 303 K using mercuric acetate as Br− ion scavenger. The stoichiometry and the oxidation products in both catalysts were found to be the same. The determined stoichiometric ratio was found to be 1:2 ([d-fru]:[NBP]. Arabinonic and formic acids were obtained as the major oxidized products of both the reactions. The kinetics of the reaction were studied as a function of temperature, ionic strength, concentration of the salt, concentration of the added reaction product, and the dielectric constant of the medium to learn the mechanistic aspects of the reaction. Possible mechanisms are proposed, which are consistent with the kinetics, stoichiometry and products of the reaction.

  2. Magnetic properties of PrX 2 compounds (X = Pt, Rh, Ru, Ir) studied by hyperfine specific heat, magnetization and neutron-diffraction measurements

    Science.gov (United States)

    Greidanus, F. J. A. M.; de Jongh, L. J.; Huiskamp, W. J.; Fischer, P.; Furrer, A.; Buschow, K. H. J.

    1983-04-01

    Magnetic ordering phenomena in rare-earth intermetallic compounds can be unravelled most advantageously in the case of simple crystallographic structure and when a combination of microscopic techniques is applied. Here we shall present the temperature and magnetic field dependence of the magnetic moment of the cubic PrX 2 compounds (X = Pt, Rh, Ru, Ir), as inferred from hyperfine specific-heat, magnetization and neutron-diffraction measurements. The results are compared with a mean-field calculation, taking crystalline electric field and bilinear (dipolar) exchange interactions into account. Adopting experimental values of the Lea, Leask and Wolf parameters x and W from inelastic neutron scattering results, we find satisfactory agreement between our magnetic data and the mean-field theory. An observed discrepancy of about 15% between the calculated and measured saturation values of the spontaneous magnetization can be explained by the presence of quadrupolar interactions.

  3. Surface studies on graphite furnace platforms covered with Pd, Rh and Ir as modifiers in graphite furnace atomic absorption spectrometry of tellurium

    Energy Technology Data Exchange (ETDEWEB)

    Pedro, Juana [Area de Química Analítica, Departamento de Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Stripekis, Jorge [Laboratorio de Análisis de Trazas, Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina); Departamento de Ingeniería Química, Instituto Tecnológico de Buenos Aires, Av. Eduardo Madero 399 (1106), Buenos Aires (Argentina); Bonivardi, Adrian [Area de Química Analítica, Departamento de Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Tudino, Mabel, E-mail: tudino@qi.fcen.uba.ar [Laboratorio de Análisis de Trazas, Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina)

    2015-05-01

    The main objective of this work is the study of correlations between the efficiency of the distribution of the permanent platinum group modifiers Pd, Rh and Ir over the graphite surface with the aim of improving analytical signal of tellurium. Modifier solution was deposited onto the platform and pyrolysed after drying. In the case of Pd, the physical vaporization/deposition technique was also tested. In order to analyze the differences amongst coverings (morphology, topology and distribution), the graphite surfaces were studied with scanning electron microscopy and energy dispersive X-ray microscopy. Micrographs for physical vaporization and pyrolytic deposition of Pd were also analyzed in order to explain the lack of signal obtained for tellurium with the first alternative. Similar micrographs were obtained for pyrolytic deposition of Ir and Rh and then, compared to those of Pd. Ir showed the most homogeneous distribution on the graphite surface and the tallest and sharpest transient. With the aim of improving the analytical signal of tellurium, the correlation between the surface studies and the tellurium transient signal (height, area and shape) is discussed. - Highlights: • Distribution of Rh, Pd and Ir onto graphite furnaces is evaluated by SEM and EDX • Micrographs and spectra showed that surface distribution could influence Te signal. • Ir showed the best signal together with the most homogeneous surface distribution. • Pd-PVD micrographs revealed the absence of graphite and no signal for Te.

  4. Ab Initio evaluation of electron transport properties of Pt, Rh, Ir, and Pd nanowires for advanced interconnect applications

    Science.gov (United States)

    Lanzillo, Nicholas A.

    2017-05-01

    The electronic and structural properties of nanowires composed of either Pt, Ir, Rh, or Pd are calculated using density functional theory and a non-equilibrium Green's function scattering approach. The results for these nanowires are compared with Cu nanowires of comparable dimensions and evaluated for potential use in interconnect technology applications. The cohesive energies of the Pt, Rh and Ir nanowires are found to be stronger than the corresponding value for bulk Cu, indicating superior structural integrity and resistance to electromigration relative to Cu. Several of the nanowires considered are found to exhibit larger values of ballistic conductance relative to Cu, with maximum conductance occurring along the [110] crystallographic direction. Electron scattering at some representative twin grain boundaries is evaluated and an empirical resistivity model is used to quantitatively estimate the impact of grain size on total resistivity.

  5. New self-assembled material based on Ru nanoparticles and 4-sulfocalix[4]arene as an efficient and recyclable catalyst for reduction of brilliant yellow azo dye in water: a new model catalytic reaction

    Science.gov (United States)

    Rambabu, Darsi; Pradeep, Chullikkattil P.; Dhir, Abhimanew

    2016-12-01

    New self-assembled material ( Ru@SC) with ruthenium nanoparticles (Ru NPs) and 4-sulfocalix[4]arene (SC) is synthesized in water at room temperature. Ru@SC is characterized by thermal gravimetric analysis, FT-IR, powder x-ray diffraction, TEM and SEM analysis. The size of Ru nanoparticles in the self-assembly is approximately 5 nm. The self-assembled material Ru@SC shows an efficient catalytic reduction of toxic `brilliant yellow' (BY) azo dye. The reduced amine products were successfully separated and confirmed by single-crystal XRD, NMR and UV-Vis spectroscopy. Ru@SC showed a better catalytic activity in comparison with commercial catalysts Ru/C (ruthenium on charcoal 5 %) and Pd/C (palladium on charcoal 5 and 10 %). The catalyst also showed a promising recyclability and heterogeneous nature as a catalyst for reduction of `BY' azo dye.

  6. CO2对Pd8Y0.23Ru合金膜氢渗透性能的影响%Effect of CO2 on Hydrogen Permeation through Pd8Y0.23Ru Alloy Membrane

    Institute of Scientific and Technical Information of China (English)

    程亮; 陆光达; 张桂凯; 王晓英

    2013-01-01

    Hydrogen permeation through a Pd8Y0.23Ru alloy membrane at 300 ℃~450 ℃ has been investigated in the presence of CO2.The results show that the hydrogen permeability is greatly decreased by CO2 addition.The higher the CO2 concentration is,the more significant the reduction of hydrogen permeation will be.The coexisting CO2 gas has a poison effect on Pd8Y0.23Ru alloy membrane.The poison effect at 450 ℃ is stronger than at 300 ℃.The reduction rate of hydrogen permeation decreases with the permeation duration.Besides poison effect,the negative effects of CO2 on H2 permeation are also caused by two other factors.Firstly,for higher concentration of CO2 (>3%),mass transfer of H2 is blocked by CO2 barrier layer near the membrane surface,which is the main reason for hydrogen permeation reduction.Secondly for lower concentrations (<1%),the main reason is the effects of CO2 adsorbing on the membrane and occupying active dissociation sites of hydrogen.%在300~450℃范围内,研究氢中加入CO2对Pd8Y0.23Ru合金膜氢渗透性能的影响.结果表明,CO2的加入会大大降低膜的氢渗透率,CO2浓度越高,氢渗透率降低越多;CO2对Pd8Y0.23Ru合金膜存在一定的毒化作用,使氢渗透率下降,450℃下的毒化作用明显强于300℃,但随着时间的延长,渗透率降低速率趋缓.CO2降低氢渗透率还有另外2个因素:当CO2浓度较高(>3%,摩尔分数)时,聚集在膜表面附近的CO2对氢气传质的阻塞作用是氢渗透率降低的主要因素;当CO2浓度较低(<1%)时,CO2在膜表面吸附,占据氢的活性点位,是氢渗透率降低的主要因素.

  7. In situ ATR-IR study of nitrite hydrogenation over Pd/Al2O3.

    NARCIS (Netherlands)

    Ebbesen, S.D.; Mojet, Barbara; Lefferts, Leonardus

    2008-01-01

    The mechanism of nitrite hydrogenation over a Pd/Al2O3 catalyst layer deposited on a ZnSe internal reflection element was investigated in water using attenuated total reflection infrared spectroscopy. Nitrite hydrogenates to NO(ads), NH2(ads), and NH+4 on the palladium surface. Hydrogenation of

  8. Electronic and magnetic properties of infinite 1D chains of paddlewheel carboxylates M2(COOR)4 (M = Mo, W, Ru, Rh, Ir, Cu)

    KAUST Repository

    Peskov, Maxim

    2013-03-14

    Dinuclear complexes of transition metals bridged by four carboxylate-groups are examples of stable atomic configurations serving as fundamental building blocks of catalysts and prototypical molecular electronic devices. The electronic structure and magnetic properties of many molecular tetracarboxylate complexes were meticulously studied; however, the properties of the one-dimensional (1D) polymeric chain of associated tetracarboxylates have so far evaded much attention. Using periodic density-functional theory calculations, we analyze the electronic structure of condensed tetracarboxylates Mo(II), W(II), Ru(II), Rh(II), Ir(II), and Cu(II). The relationship between crystal structure of the polymerized tetracarboxylates and the electronic properties of the metal-metal bond in the M24+ core is studied. The electronic effects emanating from the association of dinuclear transition metal tetracarboxylates are important for designing molecular electronic devices. In this study, its influence on both direct and indirect metal-metal interactions, and the electronic structure, in particular transport properties, is discussed. © 2013 American Chemical Society.

  9. 钛基IrO2-RuO2阳极电解处理亚甲基蓝溶液%Electrolytic Treatment of Methylene Blue Solution with Ti-based IrO2-RuO2 Anode

    Institute of Scientific and Technical Information of China (English)

    宋冠军; 杨坚; 李文祥

    2012-01-01

    采用钛基IrO2-RuO2为阳极材料,不锈钢为阴极材料,NaCl质量浓度为10g/L的溶液为电解液,对亚甲基蓝溶液进行电化学处理.实验结果表明:处理初始质量浓度为25 mg/L的亚甲基蓝溶液,电解电流0.050 A,电解20 min后亚甲基蓝去除率达95%;处理初始质量浓度为100 mg/L的亚甲基蓝溶液,电解电流0.100 A,电解30 min后亚甲基蓝去除率达98%.随着电解时间和电解电流的增加,亚甲基蓝去除率均增大.%Methylene blue solution was treated by electrochemical method using Ti-based IrO2-RuO2 as anode material, stainless steel as cathode material and NaCl solution with 10 g/L of the mass concentration as electrolyte. The experimental results show that: When the initial mass concentration of methylene blue is 25 mg/L, the electrolysis current is 0.050 A and the electrolysis time is 20 min, the removal rate of methylene blue is 95%; When the initial mass concentration of methylene blue is 100 mg/L, the electrolysis current is 0.100 A and the electrolysis time is 30 min, the removal rate of methylene blue is 98%; The removal rate of methylene blue increases with the increasing of electrolysis time and electrolysis current.

  10. Pd and Pt-Ru anode electrocatalysts supported on multi-walled carbon nanotubes and their use in passive and active direct alcohol fuel cells with an anion-exchange membrane (alcohol = methanol, ethanol, glycerol)

    Science.gov (United States)

    Bambagioni, Valentina; Bianchini, Claudio; Marchionni, Andrea; Filippi, Jonathan; Vizza, Francesco; Teddy, Jacques; Serp, Philippe; Zhiani, Mohammad

    Palladium and platinum-ruthenium nanoparticles supported on multi-walled carbon nanotubes (MWCNT) are prepared by the impregnation-reduction procedure. The materials obtained, Pd/ MWCNT and Pt-Ru/ MWCNT, are characterized by TEM, ICP-AES and XRPD. Electrodes coated with Pd/ MWCNT are scrutinized for the oxidation of methanol, ethanol or glycerol in 2 M KOH solution in half cells. The catalyst is very active for the oxidation of all alcohols, with glycerol providing the best performance in terms of specific current density and ethanol showing the lowest onset potential. Membrane-electrode assemblies have been fabricated using Pd/ MWCNT anodes, commercial cathodes and anion-exchange membrane and evaluated in both single passive and active direct alcohol fuel cells fed with aqueous solutions of 10 wt.% methanol, 10 wt.% ethanol or 5 wt.% glycerol. Pd/ MWCNT exhibits unrivalled activity as anode electrocatalyst for alcohol oxidation. The analysis of the anode exhausts shows that ethanol is selectively oxidized to acetic acid, detected as acetate ion in the alkaline media of the reaction, while methanol yields carbonate and formate. A much wider product distribution, including glycolate, glycerate, tartronate, oxalate, formate and carbonate, is obtained from the oxidation of glycerol. The results obtained with Pt-Ru/ MWCNT anodes in acid media are largely inferior to those provided by Pd/ MWCNT electrodes in alkaline media.

  11. Adsorption of NO on the Rh-13, Pd-13, Ir-13, and Pt-13 Clusters: A Density Functional Theory Investigation

    DEFF Research Database (Denmark)

    Piotrowski, Mauricio J.; Piquini, Paulo; Zeng, Zhenhua

    2012-01-01

    of real catalyst devices. In this study, we report a density functional theory study of the adsorption properties of NO on the TM13 (TM = Rh, Pd, Ir, Pt) clusters employing the projected augmented wave method. We found that the interaction of NO with TM13 is much more complex than that for NO/TM(111...... of the binding energy of NO to the TM13 clusters compared with the TM(111) surfaces, as the antibonding NO states are not occupied for NO/TM13, and the general relationship based on the d-band model between adsorption energy and the center of gravity of the occupied d-states does not hold for the studied TM13...

  12. Synthesis and Efficiency of a Spherical Macroporous Epoxy-dicyandiamide Chelate Resin for Preconcentrating and Separating Trace Au, Hg, Pd and Ru from Samples

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A novel spherical macroporous epoxy-dicyandiamide chelate resin was synthesized simply and rapidly from epoxy resin and used for the preconcentration and separation of trace amounts of Au( Ⅲ ), Hg (Ⅱ ), Pd ( Ⅳ ) and Ru ( Ⅲ ) ions from solution samples. The analyzed ions can be quantitatively concentrated by the resin at a flow rate of 2.0 mL/min at pH 4, and can also be desorbed with 15 mL of 4 mol/L HCl+0.3 g thiourea from the resin column with recoveries of 96.5%-99.0%. After the chelate resin was reused for 7 times, the recoveries of these ions were still over 92%, and 400-1 000 times of excess of Fe( Ⅲ ), Al( Ⅲ ), Ni( Ⅱ ), Mn( Ⅱ ), Cr ( Ⅲ ), Cu ( Ⅱ ), Cd ( Ⅱ ) and Pb( Ⅱ ) caused little interference with the determination of these ions by an inductively coupled plasma optical emission spectrometer (ICP-OES). The capacities of the resin for the analytes are in the range of 0.35~0.92 mmol/g. The RSDs of the proposed method are in the range of 1.1%~4.0% for each kind of the analyzed ions. The recoveries of a standard added in real solution samples are between 96.5 % and 98. 5 %, and the results for the analyzed ions in a powder sample are in good agreement with their reported values.

  13. Electrochemical oxidation of ammonia on carbon-supported bi-metallic PtM (M = Ir, Pd, SnO{sub x}) nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lomocso, Thegy L. [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis-Pasteur, Ottawa, ON K1N 6N5 (Canada); Baranova, Elena A., E-mail: elena.baranova@uottawa.ca [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis-Pasteur, Ottawa, ON K1N 6N5 (Canada)

    2011-10-01

    Highlights: > Oxidation of NH{sub 3} is investigated on carbon-supported Pt and PtM (M = Pd, Ir, SnO{sub x}) nanoparticles. > Carbon supported PtPd and PtIr nanoparticles show higher catalytic activity if compared to Pt nanocatalyst. > Pt{sub 7}Ir{sub 3} nanoparticles combine good catalytic activity and enhanced stability for NH{sub 3} oxidation. > Electronic effect between two metals in PtIr is responsible for increase in the catalytic activity. - Abstract: Ammonia electro-oxidation was studied in alkaline solution on carbon-supported Pt and bimetallic Pt{sub y}M{sub 1-y} (M = Pd, Ir, SnO{sub x} and y = 70, 50 at.%) nanoparticles. Catalysts were synthesized using the modified polyol method and deposited on carbon, resulting in 20 wt.% of metal loading. Particle size, structure and surface composition of the particles were investigated using TEM, XRD and XPS. Mean size of PtM bi-metallic nanoparticles varied between 2.0 and 4.7 nm, depending on the second metal (M). XRD revealed the structure of all bi-metallic particles to be face-centered cubic and confirmed alloy formation for Pt{sub y}Pd{sub 1-y} (y = 70, 50 at.%) and Pt{sub 7}Ir{sub 3}nanoparticles, as well as partial alloying between Pt and SnO{sub x}. Electrochemical behaviour of ammonia on Pt and PtM nanoparticles is comparable to that expected for bulk Pt and PtM alloys. Addition of Pd to Pt at the nanoscale decreased the onset potential of ammonia oxidation if compared to pure platinum nanoparticles; however stability of the catalyst was poor. For Pt{sub 7}(SnO{sub x}){sub 3}, current densities were similar to Pt, whereas catalyst stability against deactivation was improved. It is found that carbon supported Pt{sub 7}Ir{sub 3} nanoparticles combine good catalytic activity with enhanced stability for ammonia electro-oxidation. Electronic effect generated between two metals in the bimetallic nanoparticles might be responsible for increase in the catalytic activity of Pd- and Ir-containing catalysts, causing

  14. Dependency of anti-ferro-magnetic coupling strength on Ru spacer thickness of [Co/Pd]{sub n}-synthetic-anti-ferro-magnetic layer in perpendicular magnetic-tunnel-junctions fabricated on 12-inch TiN electrode wafer

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Kyo-Suk [MRAM Center, Department of Electronics, Hanyang University, Seoul 133-791 (Korea, Republic of); Samsung Electronics Co., Ltd., San #16 Banwol-dong, Hwasung-City, Gyeonggi-Do 445-701 (Korea, Republic of); Shim, Tae-Hun; Park, Jea-Gun, E-mail: parkjgL@hanyang.ac.kr [MRAM Center, Department of Electronics, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2014-07-21

    We investigated the Ru spacer-thickness effect on the anti-ferro-magnetic coupling strength (J{sub ex}) of a [Co/Pd]{sub n}-synthetic-anti-ferro-magnetic layer fabricated with Co{sub 2}Fe{sub 6}B{sub 2}/MgO based perpendicular-magnetic-tunneling-junction spin-valves on 12-in. TiN electrode wafers. J{sub ex} peaked at a certain Ru spacer-thickness: specifically, a J{sub ex} of 0.78 erg/cm{sup 2} at 0.6 nm, satisfying the J{sub ex} criteria for realizing the mass production of terra-bit-level perpendicular-spin-transfer-torque magnetic-random-access-memory. Otherwise, J{sub ex} rapidly degraded when the Ru spacer-thickness was less than or higher than 0.6 nm. As a result, the allowable Ru thickness variation should be controlled less than 0.12 nm to satisfy the J{sub ex} criteria. However, the Ru spacer-thickness did not influence the tunneling-magneto-resistance (TMR) and resistance-area (RA) of the perpendicular-magnetic-tunneling-junction (p-MTJ) spin-valves since the Ru spacer in the synthetic-anti-ferro-magnetic layer mainly affects the anti-ferro-magnetic coupling efficiency rather than the crystalline linearity of the Co{sub 2}Fe{sub 6}B{sub 2} free layer/MgO tunneling barrier/Co{sub 2}Fe{sub 6}B{sub 2} pinned layer, although Co{sub 2}Fe{sub 6}B{sub 2}/MgO based p-MTJ spin-valves ex-situ annealed at 275 °C achieved a TMR of ∼70% at a RA of ∼20 Ω μm{sup 2}.

  15. Atomic site preferences and its effect on magnetic structure in the intermetallic borides M{sub 2}Fe(Ru{sub 0.8}T{sub 0.2}){sub 5}B{sub 2} (M=Sc, Ti, Zr; T=Ru, Rh, Ir)

    Energy Technology Data Exchange (ETDEWEB)

    Brgoch, Jakoah, E-mail: jrbrgoc@gmail.com [Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Mahmoud, Yassir A. [Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Miller, Gordon J., E-mail: gmiller@iastate.edu [Department of Chemistry, Iowa State University, Ames, IA 50011 (United States)

    2012-12-15

    The site preference for a class of intermetallic borides following the general formula M{sub 2}Fe(Ru{sub 0.8}T{sub 0.2}){sub 5}B{sub 2} (M=Sc, Ti, Zr; T=Ru, Rh, Ir), has been explored using ab initio and semi-empirical electronic structure calculations. This intermetallic boride series contains two potential sites, the Wyckoff 2c and 8j sites, for Rh or Ir to replace Ru atoms. Since the 8j site is a nearest neighbor to the magnetically active Fe atom, whereas the 2c site is a next nearest neighbor, the substitution pattern should play an important role in the magnetic structure of these compounds. The substitution preference is analyzed based on the site energy and bond energy terms, both of which arise from a tight-binding evaluation of the electronic band energy, and are known to influence the locations of atoms in extended solids. According to these calculations, the valence electron-rich Rh and Ir atoms prefer to occupy the 8j site, a result also corroborated by experimental evidence. Additionally, substitution of Rh or Ir at the 8j site results in a modification of the magnetic structure that ultimately results in larger local magnetic moment on the Fe atoms. - Graphical abstract: The site preference for electron rich atoms to occupy the 8j (gray) site is identified in these intermetallic borides, while the magnetic structure is modified as a function of the substituted atoms band center. Highlights: Black-Right-Pointing-Pointer We identify the energetics dictating the site preference in a series of intermetallic borides. Black-Right-Pointing-Pointer Establish substitution rules for use in future directed synthetic preparations. Black-Right-Pointing-Pointer Identified changes in magnetic structure that accompany the site preference.

  16. Mechanistic investigation of CO2 hydrogenation by Ru(II) and Ir(III) aqua complexes under acidic conditions: two catalytic systems differing in the nature of the rate determining step.

    Science.gov (United States)

    Ogo, Seiji; Kabe, Ryota; Hayashi, Hideki; Harada, Ryosuke; Fukuzumi, Shunichi

    2006-10-21

    Ruthenium aqua complexes [(eta(6)-C(6)Me(6))Ru(II)(L)(OH(2))](2+) {L = bpy (1) and 4,4'-OMe-bpy (2), bpy = 2,2'-bipyridine, 4,4'-OMe-bpy = 4,4'-dimethoxy-2,2'-bipyridine} and iridium aqua complexes [Cp*Ir(III)(L)(OH(2))](2+) {Cp* = eta(5)-C(5)Me(5), L = bpy (5) and 4,4'-OMe-bpy (6)} act as catalysts for hydrogenation of CO(2) into HCOOH at pH 3.0 in H(2)O. The active hydride catalysts cannot be observed in the hydrogenation of CO(2) with the ruthenium complexes, whereas the active hydride catalysts, [Cp*Ir(III)(L)(H)](+) {L = bpy (7) and 4,4'-OMe-bpy (8)}, have successfully been isolated after the hydrogenation of CO(2) with the iridium complexes. The key to the success of the isolation of the active hydride catalysts is the change in the rate-determining step in the catalytic hydrogenation of CO(2) from the formation of the active hydride catalysts, [(eta(6)-C(6)Me(6))Ru(II)(L)(H)](+), to the reactions of [Cp*Ir(III)(L)(H)](+) with CO(2), as indicated by the kinetic studies.

  17. Electrochemical oxidation of trace organic contaminants in reverse osmosis concentrate using RuO2/IrO2-coated titanium anodes.

    Science.gov (United States)

    Radjenovic, Jelena; Bagastyo, Arseto; Rozendal, René A; Mu, Yang; Keller, Jürg; Rabaey, Korneel

    2011-02-01

    During membrane treatment of secondary effluent from wastewater treatment plants, a reverse osmosis concentrate (ROC) containing trace organic contaminants is generated. As the latter are of concern, effective and economic treatment methods are required. Here, we investigated electrochemical oxidation of ROC using Ti/Ru(0.7)Ir(0.3)O(2) electrodes, focussing on the removal of dissolved organic carbon (DOC), specific ultra-violet absorbance at 254 nm (SUVA(254)), and 28 pharmaceuticals and pesticides frequently encountered in secondary treated effluents. The experiments were conducted in a continuously fed reactor at current densities (J) ranging from 1 to 250 A m(-2) anode, and a batch reactor at J = 250 A m(-2). Higher mineralization efficiency was observed during batch oxidation (e.g. 25.1 ± 2.7% DOC removal vs 0% removal in the continuous reactor after applying specific electrical charge, Q = 437.0 A h m(-3) ROC), indicating that DOC removal is depending on indirect oxidation by electrogenerated oxidants that accumulate in the bulk liquid. An initial increase and subsequent slow decrease in SUVA(254) during batch mode suggests the introduction of auxochrome substituents (e.g. -Cl, NH(2)Cl, -Br, and -OH) into the aromatic compounds. Contrarily, in the continuous reactor ring-cleaving oxidation products were generated, and SUVA(254) removal correlated with applied charge. Furthermore, 20 of the target pharmaceuticals and pesticides completely disappeared in both the continuous and batch experiments when applying J ≥ 150 A m(-2) (i.e. Q ≥ 461.5 A h m(-3)) and 437.0 A h m(-3) (J = 250 A m(-2)), respectively. Compounds that were more persistent during continuous oxidation were characterized by the presence of electrophilic groups on the aromatic ring (e.g. triclopyr) or by the absence of stronger nucleophilic substituents (e.g. ibuprofen). These pollutants were oxidized when applying higher specific electrical charge in batch mode (i.e. 1.45 kA h m(-3) ROC

  18. Reactivity of [M2 (μ-Cl)2 (cod)2 ] (M=Ir, Rh) and [Ru(Cl)2 (cod)(CH3 CN)2 ] with Na[H2 B(bt)2 ]: Formation of Agostic versus Borate Complexes.

    Science.gov (United States)

    Bakthavachalam, K; Yuvaraj, K; Zafar, Mohammad; Ghosh, Sundargopal

    2016-11-21

    Treatment of [M2 (μ-Cl)2 (cod)2 ] (M=Ir and Rh) with Na[H2 B(bt)2 ] (cod=1,5-cyclooctadiene and bt=2-mercaptobenzothiazolyl) at low temperature led to the formation of dimetallaheterocycles [(Mcod)2 (bt)2 ], 1 and 2 (1: M=Ir and 2: M=Rh) and a borate complex [Rh(cod){κ(2) -S,S'-H2 B(bt)2 }], 3. Compounds 1 and 2 are structurally characterized metal analogues of 1,5-cyclooctadiene. Metal-metal bond distances of 3.6195(9) Å in 1 and 3.6749(9) Å in 2 are too long to consider as bonding. In an attempt to generate the Ru analogue of 1 and 2, that is [(Rucod)2 (bt)2 ], we have carried out the reaction of [Ru(Cl)2 (cod)(CH3 CN)2 ] with Na[H2 B(bt)2 ]. Interestingly, the reaction yielded agostic complexes [Ru(cod)L{κ(3) -H,S,S'-H2 B(bt)2 }], 4 and 5 (4: L=Cl; 5: L=C7 H4 NS2 ). One of the key differences between 4 and 5 is the presence of different ancillary ligands at the metal center. The natural bond orbital (NBO) analysis of 1 and 2 shows that there is four lone pairs of electrons on each metal center with a significant amount of d character. Furthermore, the electronic structures and the bonding of these complexes have been established on the ground of quantum-chemical calculations. All of the new compounds were characterized by IR, (1) H, (11) B, (13) C NMR spectroscopy, and X-ray crystallographic analysis.

  19. Copper-based alloys, crystallographic and crystallochemical parameters of alloys in binary systems Cu-Me (Me=Co, Rh, Ir, Cu, Ag, Au, Ni, Pd, Pt)

    Energy Technology Data Exchange (ETDEWEB)

    Porobova, Svetlana, E-mail: porobova.sveta@yandex.ru; Loskutov, Oleg, E-mail: lom58@mail.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); Markova, Tat’jana, E-mail: patriot-rf@mail.ru [Siberian State Industrial University. 42 Kirov St., Novokuznetsk, 654007 (Russian Federation); Klopotov, Vladimir, E-mail: vdklopotov@mail.ru [Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation); Klopotov, Anatoliy, E-mail: klopotovaa@tsuab.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); National Research Tomsk State University, 36, Lenin Ave., Tomsk, 634050 (Russian Federation); Vlasov, Viktor, E-mail: vik@tsuab.ru [Tomsk State University of Architecture and Building, Russia, Tomsk, 2 Solyanaya sq, Tomsk, 634003 (Russian Federation); Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

    2016-01-15

    The article presents the results of the analysis of phase equilibrium of ordered phases in binary systems based on copper Cu- Me (where Me - Co, Rh, Ir, Ag, Au, Ni, Pd, Pt) to find correlations of crystallochemical and crystallographic factors. It is established that the packing index in disordered solid solutions in binary systems based on copper is close to the value of 0.74 against the background of an insignificant deviation of atomic volumes from the Zen’s law.

  20. FT-IR Spectroscopic characterization of the intermediates in the selective catalytic reduction of NO with methane on Pd/ZrO(formula)-WO(formula) catalyst

    OpenAIRE

    Çayırtepe, İlknur

    2004-01-01

    Cataloged from PDF version of article. This work involves in situ FT-IR spectroscopic study of the routes of formation, composition and thermal stability of strongly bound NOx complexes on the surface of Pd/tungstated zirconia, and transformation of the surface NOx complexes in the presence of methane in order to elucidate the mechanism of selective catalytic reduction of NO with methane. Sol-gel polymer-template synthesis was chosen to obtain high surface area in the prepar...

  1. Screening on binary Zr-1X (X = Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi) alloys with good in vitro cytocompatibility and magnetic resonance imaging compatibility.

    Science.gov (United States)

    Zhou, F Y; Qiu, K J; Li, H F; Huang, T; Wang, B L; Li, L; Zheng, Y F

    2013-12-01

    In this study, the microstructures, mechanical properties, corrosion behaviors, in vitro cytocompatibility and magnetic susceptibility of Zr-1X alloys with various alloying elements, including Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi, were systematically investigated to explore their potential use in biomedical applications. The experimental results indicated that annealed Zr-1X alloys consisted entirely or primarily of α phase. The alloying elements significantly increased the strength and hardness of pure Zr and had a relatively slight influence on elastic modulus. Ru was the most effective enhancing element and Zr-1Ru alloy had the largest elongation. The results of electrochemical corrosion indicated that adding various elements to Zr improved its corrosion resistance, as indicated by the reduced corrosion current density. The extracts of the studied Zr-1X alloys produced no significant deleterious effects on osteoblast-like cells (MG 63), indicating good in vitro cytocompatibility. All except for Zr-1Ag alloy showed decreased magnetic susceptibility compared to pure Zr, and Zr-1Ru alloy had the lowest magnetic susceptibility value, being comparable to that of α' phase Zr-Mo alloy and Zr-Nb alloy and far lower than that of Co-Cr alloy and Ti-6Al-4V alloy. Among the experimental Zr-1X alloys, Zr-1Ru alloy possessing high strength coupled with good ductility, good in vitro cytocompatibility and low magnetic susceptibility may be a good candidate alloy for medical devices within a magnetic resonance imaging environment. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  2. Counterion influence on the vibrational wavenumbers in ternary and quaternary metal hydride salts, A2MH6 (A = alkali metal, alkaline earth, and lanthanides; M = Ir, Fe, Ru, Os, Pt, Mn).

    Science.gov (United States)

    Gilson, Denis F R; Moyer, Ralph O

    2012-02-06

    The wavenumbers of the ν(3) metal-hydrogen stretching mode (T(1u)) in the IR spectra of both ternary and quaternary hexahydrido salts of transition metals from groups 7 to 10 ([Mn(I)H(6)](5-), [Fe(II)H(6)](4-), [Ru(II)H(6)](4-), [Os(II)H(6)](4-), [Ir(III)H(6)](3-), and [Pt(IV)H(6)](2-)) depend linearly upon the ionization energies of the counterions (alkali metal, alkaline earth, and lanthanide) with a separate line for each metal. This relationship provides quantitative support for the charge-transfer mechanism for explaining the stabilities of these compounds.

  3. Catalytic Hydrogenation of Dimethyl Terephthalat to Prepare Dimethyl 1,4-Cyclohexanedicarboxylate over Ru-Pd/C Catalyst%Ru-Pd/C催化对苯二甲酸二甲酯加氢制备1,4-环己烷二甲酸二甲酯

    Institute of Scientific and Technical Information of China (English)

    臧涵; 夏志; 申卫卫; 宋金文

    2014-01-01

    采用纳米级Ru-Pd/C催化剂,在温和条件下将其应用于对苯二甲酸二甲酯(DMT)加氢制备1,4-环己烷二甲酸二甲酯(DMCD)的反应.考察了溶剂、反应温度、压力、催化剂用量对DMT加氢的影响.结果表明,在5 000mL高压反应釜中,最佳工艺条件为:温度140 ℃、压力4.0 MPa、溶剂异丙醇2000 mL、DMT 1 300 g、催化剂65g,在该条件下,DMT转化率为99.8%,DMCD选择性为96.3%.保持反应条件不变,催化剂循环使用22次后,DMT转化率为99.0%,DMCD选择性为95.1%.

  4. EVALUACIÓN DE CELDAS DE COMBUSTIBLE DE ELECTROLITO POLIMÉRICO CON ÁNODOS Pt-M (M= Sn, Ru e Ir PARA LA OXIDACIÓN DE H2 Y CO

    Directory of Open Access Journals (Sweden)

    BIBIAN HOYOS

    2008-01-01

    Full Text Available Se evaluó el desempeño de celdas de combustible de electrolito polimérico alimentadas con hidrógeno, CO y una mezcla H2-(2%CO, utilizando oxígeno en el cátodo. Para la oxidación de los combustibles, se probaron seis catalizadores: Pt, Pt85Ru15, Pt50Ru50, Pt90Ir10, Pt50Ir50 y Pt90Sn10. Como catalizador en el cátodo se usó platino puro. Todos los catalizadores fueron soportados en carbón Vulcan XC-72R ®. La composición de los catalizadores preparados fue verificada en un Microscopio Electrónico de Barrido (SEM y las pruebas de desempeño de las celdas construidas se realizaron mediante curvas corriente-potencial. Los resultados muestran que la técnica depreparación de los electrodos produce mezclas catalíticas con composiciones muy cercanas a las nominales. Las mezclas catalíticas Pt-Ir son las que presentan el desempeño más bajo para las condiciones evaluadas en este trabajo. La mezcla Pt90Sn10 presentó un desempeño similar al del platino a bajas corrientes cuando la celda de combustible fue alimentada con hidrógeno puro y superó el desempeño de los demás catalizadores cuando la celda se alimentó con H2/(2%CO. El electrodo Pt90Sn10 pierde actividad catalítica cuando se emplea CO puro.

  5. Synthesis, crystal structure and physical properties of EuTGe{sub 3} (T = Co, Ni, Rh, Pd, Ir, Pt) single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bednarchuk, Oleksandr; Gągor, Anna; Kaczorowski, Dariusz, E-mail: D.Kaczorowski@int.pan.wroc.pl

    2015-02-15

    Highlights: • Single crystals of EuTGe{sub 3} (T = Co, Ni, Rh, Pd, Ir, Pt) compounds were prepared. • The crystal structures were refined from single-crystal X-ray diffraction data. • The physical properties of oriented single crystals were determined. • For each compound, an antiferromagnetic ordering was found at low temperatures. - Abstract: Single crystals of six EuTGe{sub 3} compounds with T = Co, Ni, Rh, Pd, Ir and Pt were prepared by high-temperature solution growth method. Their crystal structures of the BaNiSn{sub 3}-type were refined from single-crystal X-ray diffraction data. The physical properties of oriented single-crystalline specimens were studied by means of magnetic susceptibility, heat capacity and electrical resistivity measurements. For each compound, an antiferromagnetic ordering was found to set in at low temperatures due to localized magnetic moments carried on divalent Eu ions. Despite the same crystal structure, the EuTGe{sub 3} compounds exhibit diverse magnetic structures with different directions of the ordered magnetic moments and a variety of dissimilar mutual arrangements of adjacent spins.

  6. Synthesis and evaluation of new salicylaldehyde-2-picolinylhydrazone Schiff base compounds of Ru(II), Rh(III) and Ir(III) as in vitro antitumor, antibacterial and fluorescence imaging agents.

    Science.gov (United States)

    Palepu, Narasinga Rao; Nongbri, S L; Premkumar, J Richard; Verma, Akalesh Kumar; Bhattacharjee, Kaushik; Joshi, S R; Forbes, Scott; Mozharivskyj, Yurij; Thounaojam, Romita; Aguan, K; Kollipara, Mohan Rao

    2015-06-01

    Reaction of salicylaldehyde-2-picolinylhydrazone (HL) Schiff base ligand with precursor compounds [{(p-cymene)RuCl2}2] 1, [{(C6H6)RuCl2}2] 2, [{Cp*RhCl2}2] 3 and [{Cp*IrCl2}2] 4 yielded the corresponding neutral mononuclear compounds 5-8, respectively. The in vitro antitumor evaluation of the compounds 1-8 against Dalton's ascites lymphoma (DL) cells by fluorescence-based apoptosis study and by their half-maximal inhibitory concentration (IC50) values revealed the high antitumor activity of compounds 3, 4, 5 and 6. Compounds 1-8 render comparatively lower apoptotic effect than that of cisplatin on model non-tumor cells, i.e., peripheral blood mononuclear cells (PBMC). The antibacterial evaluation of compounds 5-8 by agar well-diffusion method revealed that compound 6 is significantly effective against all the eight bacterial species considered with zone of inhibition up to 35 mm. Fluorescence imaging study of compounds 5-8 with plasmid circular DNA (pcDNA) and HeLa RNA demonstrated their fluorescence imaging property upon binding with nucleic acids. The docking study with some key enzymes associated with the propagation of cancer such as ribonucleotide reductase, thymidylate synthase, thymidylate phosphorylase and topoisomerase II revealed strong interactions between proteins and compounds 5-8. Conformational analysis by density functional theory (DFT) study has corroborated our experimental observation of the N, N binding mode of ligand. Compounds 5-8 exhibited a HOMO (highest occupied molecular orbital)-LUMO (lowest unoccupied molecular orbital) energy gap 2.99-3.04 eV. Half-sandwich ruthenium, rhodium and iridium compounds were obtained by treatment of metal precursors with salicylaldehyde-2-picolinylhydrazone (HL) by in situ metal-mediated deprotonation of the ligand. Compounds under investigation have shown potential antitumor, antibacterial and fluorescence imaging properties. Arene ruthenium compounds exhibited higher activity compared to that of Cp*Rh/Cp*Ir

  7. Electrocatalytic oxidation of GMP on an ITO electrode modified by the photoposition of Pd nanoparticles onto a monolayer TiO2-Ru(Ⅱ)complex hybrid film%Pd纳米粒子敏化的纳米单层TiO2-Ru(Ⅱ)螯合物修饰电极对单磷酸鸟苷的电催化氧化行为

    Institute of Scientific and Technical Information of China (English)

    陈锡安; 王舜; 林娟娟; 刘爱丽; 黄少铭

    2011-01-01

    利用LB膜技术可控制备了纳米单层的二氧化钛-有机钌螯合物杂化膜,并研究了上述无机-有机杂化膜修饰电极在Pd纳米粒子敏化后对单磷酸鸟苷(GMP)的电催化氧化行为.实验结果表明:(1)纳米单层TiO2/[Ru(phen)2(dC18bpy)]2+(简称为TiO2-Ru)杂化膜的平均厚度为(3.2±0.5)nm;(2)在光照条件下TiO2-Ru杂化膜能有效催化还原[Pd(NH3)4]2+形成粒径位于20~200 nm之间的Pd纳米粒子;(3)纳米单层TiO2-Ru/Pd杂化膜能高效催化氧化具有供电子能力的单磷酸鸟苷(GMP),与纳米单层TiO2-Ru杂化膜修饰的ITO电极(ITO/TiO2-Ru)相比,当工作电压为1200mV时,ITO/TiO2-Ru/Pd电极在含有1×10-3 mol L-1 GMP的磷酸盐缓冲液中,单位面积的催化氧化电流提高了约36倍;(4)Pd纳米粒子的引入消除了金属钌螯合物中配体对电子传递的阻碍作用,改变了电子传递途径,从而有效减少了电子空穴对的复合,提高了杂化膜修饰电极(ITO/TiO2-Ru/Pd)的电子传递效率.%An indium tin oxide (ITO) electrode coated with monolayer TiO2/[Ru(phen)2(dC18bpy)]2+ (phen =1,10-phenanthroline, dC18bpy = 4,4'-dioctadecyl-2,2'-bipyridyl) hybrid film (denoted as ITO/TiO2-Ru) has been prepared by the modified Langmuir-Blodgctt (LB) method, and the electrocatalytic oxidation of mononuclcotide of guanosine 5'-monophosphate (GMP) on an ITO/TiO2-Ru electrode after Pd-photodeposition (denoted as ITO/TiO2-Ru/Pd) has been studied.Atomic force microscopy reveals that the single-layered hybrid film of TiO2 nanosheets/[Ru(phen)2(dCl 8bpy)]2+ is closely packed at a surface pressure of 25 mN m-1 and has a thickness of (3.20 ± 0.5) nm.X-ray photoelectron spectra shows the formation of Pd nanoparticlcs on the surface of hybrid film with radii of 20~200 nm by the reduction of [Pd(NH3)4]2+ under light irradiation.When being applied to oxidize GMP, a larger catalytic oxidative current is achieved on thc ITO/TiO2-Ru/Pd electrode at the external potential above 700 m

  8. First principles study on the interfacial properties of NM/graphdiyne (NM = Pd, Pt, Rh and Ir): The implications for NM growing

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Zhansheng; Li, Shuo; Lv, Peng [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007 (China); He, Chaozheng, E-mail: hecz2013@nynu.edu.cn [College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061 (China); Ma, Dongwei [School of Physics, Anyang Normal University, Anyang 455000 (China); Yang, Zongxian, E-mail: yzx@henannu.edu.cn [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007 (China); Collaborative Innovation Center of Nano Functional Materials and Applications, Kaifeng (China)

    2016-01-01

    Graphical abstract: - Highlights: • The NM adatoms belong to embedded adsorption in 18C-hexagon of GDY. • The Rh and Ir/GDY can be applied to single metal catalysts or sensors. • A simple linear relationship between E{sub e-ads} and E{sub b} is presented. • The linear relationship can be used in the noble metal modified GDY. - Abstract: Based on the dispersion-corrected density functional calculations (DFT-D), we systematically studied the adsorption of noble metals (NM), Pd, Pt, Rh and Ir, on graphdiyne (GDY). We present a systematic study on the geometry, embedded adsorption energy and electronic structure of four different adatoms adsorbed on the GDY. The strong interaction between the NM adatoms and the GDY substrate is found with the NM embedded in the 18C-hexagon of the GDY. We investigated the mobility of the NM adatoms on the GDY, and found that the mobility barrier energy increases along with the increasing of the embedded adsorption energy. We present the NM adatoms growth of high concentrations on the GDY. Upon the analysis of the electronic structure and the frontier molecular orbitals, Rh and Ir adatoms of low concentrations (about 1.37 at%) on the GDY have the potential to be applied as single metal catalysts or gas molecule sensors.

  9. Metal-carbon nanocomposites based on activated IR pyrolized polyacrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Efimov, Mikhail N.; Zhilyaeva, Natalya A.; Vasilyev, Andrey A.; Muratov, Dmitriy G.; Zemtsov, Lev M.; Karpacheva, Galina P. [A.V. Topchiev Institute of Petrochemical Synthesis RAS, Leninskiy Prospekt 29, 119991 Moscow Russia (Russian Federation)

    2016-05-18

    In this paper we report about new approach to preparation of metal-carbon nanocomposites based on activated carbon. Polyacrylonitrile is suggested as a precursor for Co, Pd and Ru nanoparticles carbon support which is prepared under IR pyrolysis conditions of a precursor. The first part of the paper is devoted to study activated carbon structural characteristics dependence on activation conditions. In the second part the effect of type of metal introduced in precursor on metal-carbon nanocomposite structural characteristics is shown. Prepared AC and nanocomposite samples are characterized by BET, TEM, SEM and X-ray diffraction.

  10. Computational Study of Metal-Dinitrogen Keggin-Type Polyoxometalate Complexes [PW11O39M(II)N2)](5-) (M = Ru, Os, Re, Ir): Bonding Nature and Dinitrogen Splitting.

    Science.gov (United States)

    Liu, Chun-Guang; Liu, Shuang; Zheng, Ting

    2015-08-17

    Molecular geometry, electronic structure, and metal-dinitrogen bonding nature of a series of metal-dinitrogen derivatives of Keggin-type polyoxometalates (POMs) [PW11O39M(II)N2)](5-) (M = Ru, Os, Re, Ir) have been studied by using a density functional theory (DFT) method with the M06L functional. Among these Keggin-type POM complexes, Os- and Re-substituted POM complexes are the most active for N2 adsorption with considerable adsorption energy. The electronic structure analysis shows that Os(II) and Re(II) centers in their metal-dinitrogen POM complexes possess π(2)xzπ(2)yzπ(2)xy and π(2)xzπ(2)yzπ(1)xy configurations, respectively. DFT-M06L calculations show that the possible synthesis routes proposed in this work for the Ru-, Os-, and Re-dinitrogen POM complexes are thermodynamically feasible under various solvent environments. Meanwhile, the Re-dinitrogen POM complex was assessed for the direct cleavage of dinitrogen molecule. In the reaction mechanism, a dimeric Keggin-type POM derivative of rhenium could represent the intermediate which undergoes N-N bond scission. The calculated free energy barrier (ΔG(⧧)) for a transition state with a zigzag conformation is 16.05 kcal mol(-1) in tetrahydrofuran, which is a moderate barrier for the cleavage of the N-N bond when compared with the literature values. In conclusion, regarding the direct cleavage of the dinitrogen molecule, the findings would be very useful to guide the search for a potential N2 cleavage compound into totally inorganic POM fields.

  11. Fermi-liquid behavior of binary intermetallic compounds Y3 M (M  =  Co, Ni, Rh, Pd, Ir, Pt)

    Science.gov (United States)

    Strychalska-Nowak, Judyta; Wiendlocha, Bartłomiej; Hołowacz, Katarzyna; Reczek, Paula; Podgórski, Mateusz; Winiarski, Michał J.; Klimczuk, Tomasz

    2017-06-01

    A series of polycrystalline samples of Y3 M (M  =  Co, Ni, Rh, Pd, Ir, Pt), intermetallic binary compounds were synthesized by the arc-melting method. Powder x-ray diffraction (pXRD) confirmed the orthorhombic cementite-type crystal structure and allowed for the estimation of the lattice parameters. Physical properties were investigated by means of electrical resistivity and heat capacity measurements between 1.9 K and 300 K. All tested compounds show metallic-like behaviour with RRR values ranging from 1.3 to 8.3, and power-law ρ \\propto {{T}n} temperature dependence of resistivity was observed, with 1.6≤slant n≤slant 2.2 . No superconductivity was detected above 1.9 K. The Debye temperature, estimated from the low temperature heat capacity fit, ranged from 180 K (Y3Pt) to 222 K (Y3Co). The highest value of the Sommerfeld coefficient γ was found for Y3Pd (19.5 mJ mol-1 K-2). The pXRD pattern of Y3Rh indicated the presence of Y5Rh2, a previously unreported Pd5B2-type phase, whose unit cell parameters were refined using the LeBail method. Density functional theory calculations were performed and theoretical results revealed strong enhancement of the measured electronic specific heat, which was 30%-100% larger than computed. Quadratic temperature dependence of resistivity and enhanced electronic specific heat indicated a Fermi-liquid behavior of electrons in these materials.

  12. Radiochemical neutron activation analysis for 36 elements in geological material: Au, Ag, Bi, Br, Cd, Cs, Ge, In, Ir, Ni, Os, Pd, Rb, Re, Sb, Se, Sn, Te, Tl, U, and Zn as well as Sc, Y, and REE

    Energy Technology Data Exchange (ETDEWEB)

    Anders, E; Wolf, R; Morgan, J W; Ebihara, M; Woodrow, A B; Janssens, M J; Hertogen, J

    1988-01-01

    In lunar and terrestrial rocks and in meteorites, the radiochemical neutron activation method decribed here enables determination of the 21 trace and ultratrace elements Ag, Au, Bi, Br, Cd, Cs, Ga, Ge, In, Ir, Ni, Os, Pd, Rb, Re, Sb, Se, Te, Tl, U, Zn, as well as 13 rare earth elements (REE), Sc and Y. Materials, techniques and procedures are discussed. 81 refs.

  13. The silicides YT{sub 2}Si{sub 2} (T = Co, Ni, Cu, Ru, Rh, Pd). A systematic study by {sup 89}Y solid-state NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hoeting, Christoph; Rodewald, Ute C.; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Eckert, Hellmut [Muenster Univ. (Germany). Inst. fuer Physikalische Chemie; Matar, Samir F. [CNRS Bordeaux Univ., Pessac (France). ICMCB

    2014-03-15

    The ThCr{sub 2}Si{sub 2}-type silicides YT{sub 2}Si{sub 2} (T = Co, Ni, Cu, Ru, Rh, Pd) were synthesized from the elements by arc-melting. They were characterized by powder X-ray diffraction, and the structures were refined on the basis of single-crystal X-ray diffractometer data. The course of the lattice parameters shows a distinct anomaly for YRu{sub 2}Si{sub 2} which has by far the smallest c/a ratio along with elongated Y-Si distances. Systematic {sup 89}Y solid-state NMR spectra show large Knight shifts arising from unpaired conduction electron spin density near the Fermi edge. The Knight shift decreases with increasing valence electron count (VEC), reflecting the sensitivity of this parameter to electronic properties. The particularly strong structural distortion observed in YRu{sub 2}Si{sub 2} manifests itself in a sizeable magnetic shielding anisotropy. Electronic structure calculations for YRu{sub 2}Si{sub 2} and YRh{sub 2}Si{sub 2} reveal similar projected density of states (PDOS) shapes with an energy upshift of the Fermi level in YRh{sub 2}Si{sub 2} due to the extra electron brought in by Rh. As a consequence, the PDOS at the Fermi energy is twice as large in the Ru compound as in the Rh compound. While both compounds show the major bonding interaction within the T{sub 2}Si{sub 2} layers, YRh{sub 2}Si{sub 2} exhibits significantly stronger Y-Si bonding. (orig.)

  14. A Theoretical Study of Addition Reactions of L4M(M = Rh, Ir) and L2M(M = Pd, Pt) to Li+@C60.

    Science.gov (United States)

    Yang, Ming-Chung; Sharma, Akhilesh Kumar; Sameera, W M Chamil; Morokuma, Keiji; Su, Ming-Der

    2017-03-16

    The addition reaction of M(Cl)(CO)(PPh3)2 (M = Rh, Ir) and M(PPh3)2 (M = Pd, Pt) fragments with X@C60 (X = 0, Li+) were characterized by density functional theory (DFT) and the artificial force-induced reaction (AFIR) method. The calculated free energy profiles suggested that the η2[6:6]-addition is the most favorable reaction, which is consistent with the experimental observations. In the presence of Li+ ion, the reaction is highly exothermic, leading to η2[6:6] product of L4IrLi+@C60. In contrast, an endothermic reaction was observed in the absence of a Li+ ion. The encapsulated Li+ ion can enhance the thermodynamic stability of the η2[6:6] product. The energy decomposition analysis showed that the interaction between metal fragment and X@C60 fragment is the key for the thermodynamic stability. Among the group IA and IIA metal cations, Be2+ encapsulation is the best candidate for the development of new fullerene-transition metal complexes, which will be useful for future potential applications such as solar cells, catalysts, and electronic devices.

  15. Novel PdCI 2 (RuCI 3)/ZrO2SO3 Catalysts for Synthesis of Carbamates by Oxidative Carbonylation of Amines%一种胺氧化羰化制氨基甲酸酯新催化剂体系

    Institute of Scientific and Technical Information of China (English)

    石峰; 司马天龙; 邓友全

    2000-01-01

    Novel combined PdC12 (RuCl3) with ZrO2-SO3 catalysts were developed for the synthesis of carbamates by oxidative carbonylation of aliphatic and aromatic amines. At 170 ℃ and 4.0 MPa, oxidative carbonylation of aromatic amines to the corresponding carbamates over this catalyst system could be proceeded with a high conversion and selectivity. Especially when β-naphthylamine was used as the substrate, 100% conversion and 95% selectivity were obtained in only 15 min. The catalytic performance of PdCl2/ZrO2-SO3 was better than that of RuCl3/ZrO2-SO3 for such oxidative carbonylation reaction.Possible role of ZrO2-SO3 as co-catalyst was also conjectured.

  16. Anodic incineration of phthalic anhydride using RuO2–IrO2–SnO2–TiO2 coated on Ti anode

    Directory of Open Access Journals (Sweden)

    S. Chellammal

    2016-11-01

    Full Text Available Phthalic anhydride is a toxic and non-biodegradable organic compound and is widely used for the production of dyes. This paper has investigated the electrochemical oxidation of phthalic anhydride in an undivided cell at different experimental parameters such as pH, current density and supporting electrolytes on the anode of titanium substrate coated with mixed metal oxides of RuO2, IrO2, SnO2 and TiO2 prepared by thermal decomposition method. The surface morphology and the structure of the above anode were characterized by scanning electron microscopy, electron dispersion microscopy and X-ray diffraction. The study shows that the electrode exhibits good electro catalytic activity together with chemical stability during the treatment of the phthalic anhydride. At pH 3, the maximum removal of COD of 88% with energy consumption of 30.5 kW h kg−1 was achieved by the addition of 10 g l−1 NaCl in 0.2 mol dm−3 Na2SO4 at 5 Adm−2. This electrolytic investigation offers an attractive alternative method for the destruction of industrial effluents contaminated with phthalic anhydride.

  17. CO2 capture and separation from N2/CH4 mixtures by Co@B8/Co@B8(-) and M@B9/M@B9(-) (M = Ir, Rh, Ru) clusters: a theoretical study.

    Science.gov (United States)

    Wang, Weihua; Zhang, Xiaoxiao; Li, Ping; Sun, Qiao; Li, Zhen; Ren, Cong; Guo, Chao

    2015-01-29

    The discovery of advanced materials with high selectivity and efficiency is essential to realize practical carbon capture and sequestration. Here, we have investigated the interactions of the Co@B8/Co@B8(-) and M@B9/M@B9(-) (M = Ir, Rh, Ru) clusters with CO2, N2, and CH4 gas molecules theoretically. We found that neutral boron clusters have weak interaction with CO2, N2, and CH4 molecules. Similarly, the clusters with their negative charge states have also weak interaction with N2 and CH4 molecules. However, anionic clusters have a strong interaction with CO2, which can be explained by the Lewis acid-base interaction as CO2 (Lewis acid) can gain electron easily from the electron-rich anionic clusters. Moreover, the kinetic stability of the formed complexes after CO2 capture has been validated by ab initio molecular dynamics. In all, the present study demonstrates, for the first time, that the anionic boron wheel ring clusters can be used as potential advanced materials for CO2 capture and separation from flue gas and natural gas mixtures.

  18. Crystal field splittings of PrX 2 compounds (X=Pt, Rh, Ir, Ru, Ni) studied by inelastic neutron scattering

    Science.gov (United States)

    Greidanus, F. J. A. M.; De Jongh, L. J.; Huiskamp, W. J.; Furrer, A.; Buschow, K. H. J.

    1983-01-01

    Neutron inelastic scattering experiments have been performed on polycrystalline samples of the cubic Laves phase compounds PrX 2(X=Pt, Rh, Ir, Ni). Measurements in the paramagnetic state yield LLW parameters 0.6< x<1 and W<0. In this region various levels cross at an x value 0.86 and as a consequence the electronic ground state in the paramagnetic regime is either the singlet Γ 1, or the non-magnetic doublet Γ 3. Measurements in the ferromagnetic state support these conclusions. The crystal-field parameters obtained can be used in model calculations of some macroscopic quantities, in particular the specific heat and the spontaneous magnetization. The variation of the x values in the present series of Laves phase compounds evidences the presence of a contribution by conduction electrons to the crystal field.

  19. Ru Nanoframes with an fcc Structure and Enhanced Catalytic Properties.

    Science.gov (United States)

    Ye, Haihang; Wang, Qingxiao; Catalano, Massimo; Lu, Ning; Vermeylen, Joseph; Kim, Moon J; Liu, Yuzi; Sun, Yugang; Xia, Xiaohu

    2016-04-13

    Noble-metal nanoframes are of great interest to many applications due to their unique open structures. Among various noble metals, Ru has never been made into nanoframes. In this study, we report for the first time an effective method based on seeded growth and chemical etching for the facile synthesis of Ru nanoframes with high purity. The essence of this approach is to induce the preferential growth of Ru on the corners and edges of Pd truncated octahedra as the seeds by kinetic control. The resultant Pd-Ru core-frame octahedra could be easily converted to Ru octahedral nanoframes of ∼2 nm in thickness by selectively removing the Pd cores through chemical etching. Most importantly, in this approach the face-centered cubic (fcc) crystal structure of Pd seeds was faithfully replicated by Ru that usually takes an hcp structure. The fcc Ru nanoframes showed higher catalytic activities toward the reduction of p-nitrophenol by NaBH4 and the dehydrogenation of ammonia borane compared with hcp Ru nanowires with roughly the same thickness.

  20. Synthesis and characterization of (smif)2M(n) (n = 0, M = V, Cr, Mn, Fe, Co, Ni, Ru; n = +1, M = Cr, Mn, Co, Rh, Ir; smif =1,3-di-(2-pyridyl)-2-azaallyl).

    Science.gov (United States)

    Frazier, Brenda A; Bartholomew, Erika R; Wolczanski, Peter T; DeBeer, Serena; Santiago-Berrios, Mitk'El; Abruña, Hector D; Lobkovsky, Emil B; Bart, Suzanne C; Mossin, Susanne; Meyer, Karsten; Cundari, Thomas R

    2011-12-19

    A series of Werner complexes featuring the tridentate ligand smif, that is, 1,3-di-(2-pyridyl)-2-azaallyl, have been prepared. Syntheses of (smif)(2)M (1-M; M = Cr, Fe) were accomplished via treatment of M(NSiMe(3))(2)(THF)(n) (M = Cr, n = 2; Fe, n = 1) with 2 equiv of (smif)H (1,3-di-(2-pyridyl)-2-azapropene); ortho-methylated ((o)Mesmif)(2)Fe (2-Fe) and ((o)Me(2)smif)(2)Fe (3-Fe) were similarly prepared. Metatheses of MX(2) variants with 2 equiv of Li(smif) or Na(smif) generated 1-M (M = Cr, Mn, Fe, Co, Ni, Zn, Ru). Metathesis of VCl(3)(THF)(3) with 2 Li(smif) with a reducing equiv of Na/Hg present afforded 1-V, while 2 Na(smif) and IrCl(3)(THF)(3) in the presence of NaBPh(4) gave [(smif)(2)Ir]BPh(4) (1(+)-Ir). Electrochemical experiments led to the oxidation of 1-M (M = Cr, Mn, Co) by AgOTf to produce [(smif)(2)M]OTf (1(+)-M), and treatment of Rh(2)(O(2)CCF(3))(4) with 4 equiv Na(smif) and 2 AgOTf gave 1(+)-Rh. Characterizations by NMR, EPR, and UV-vis spectroscopies, SQUID magnetometry, X-ray crystallography, and DFT calculations are presented. Intraligand (IL) transitions derived from promotion of electrons from the unique CNC(nb) (nonbonding) orbitals of the smif backbone to ligand π*-type orbitals are intense (ε ≈ 10,000-60,000 M(-1)cm(-1)), dominate the UV-visible spectra, and give crystals a metallic-looking appearance. High energy K-edge spectroscopy was used to show that the smif in 1-Cr is redox noninnocent, and its electron configuration is best described as (smif(-))(smif(2-))Cr(III); an unusual S = 1 EPR spectrum (X-band) was obtained for 1-Cr.

  1. Direct Observation of the Kinetically Relevant Site of CO Hydrogenation on Supported Ru Catalyst at 700 K by Time-Resolved FT-IR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Frei, Heinz; Wasylenko, Walter; Frei, Heinz

    2008-06-04

    Time-resolved FT-IR spectra of carbon monoxide hydrogenation over alumina-supported ruthenium particles were recorded on themillisecond time scale at 700 K using pulsed release of CO and a continuous flow of H2/N2 (ratio 0.067 or 0.15, 1 atm total pressure). Adsorbed carbon monoxide was detected along with gas phase products methane (3016 and 1306 cm-1), water (1900 +- 1300 cm-1), and carbon dioxide (2348 cm-1). Aside from adsorbed CO, no other surface species were observed. The rate of formation of methane is 2.5 +- 0.4 s-1 and coincides with the rate of carbon dioxide growth (3.4 +- 0.6 s-1), thus indicating that CH4 and CO2 originate from a common intermediate. The broad band of adsorbed carbon monoxide has a maximum at 2010 cm-1 at early times (36 ms) that shifts gradually to 1960 cm-1 over a period of 3 s as a result of the decreasing surface concentration of CO. Kinetic analysis of the adsorbed carbon monoxide reveals that surface sites absorbing at the high frequency end of the infrared band are temporally linked to gas phase product growth. Specifically, a (linear) CO site at 2026 cm-1 decays with a rate constant of 2.9 +- 0.1 s-1, which coincides with the rise constant of CH4. This demonstrates that the linear CO site at 2026 cm-1 is the kinetically most relevant one for the rate-determining CO dissociation step under reaction conditions at 700 K.

  2. Fabrication of MgAl2Si2O8 : M0.01 (M = Ni2+, Cu2+, Pd2+, Pt2+ and Ru3+): catalytic effects for the reduction of 2- or 4-nitroanilines in water

    Indian Academy of Sciences (India)

    Serkan Dayan; Sevgi Öztürk; Nilgün Kayaci; Nilgun Kalaycioglu Ozpozan; Esra Öztürk

    2015-10-01

    Five new MgAl2Si2O8 : M0.01 (M = Ni2+, Cu2+, Pd2+, Pt2+ and Ru3+) materials were developed for the reduction of nitroarenes as catalysts by conventional solid state reaction at 1300°C. The prepared materials were characterized by thermal analysis, Fourier transform infrared spectroscopy, X-ray powder diffraction analysis, scanning electron microscopy, energy-dispersive X-ray analysis and nitrogen adsorption–desorption analysis. The catalytic activities of the prepared catalysts were tested in the reduction of 2- or 4-nitroanilines in aqueous media at ambient temperature in the presence of NaBH4 by UV–vis spectrophotometer. Furthermore, the MgAl2Si2O8 : M0.01 catalysts can be recovered by filtration and reused for five cycles for the reduction of 2-nitroaniline. These results show that the MgAl2Si2O8 : M0.01 catalysts can be used in practical applications in the reduction of nitroanilines.

  3. Electrochemical degradation of the β-blocker metoprolol by Ti/Ru 0.7 Ir 0.3 O 2 and Ti/SnO 2-Sb electrodes.

    Science.gov (United States)

    Radjenovic, Jelena; Escher, Beate I; Rabaey, Korneel

    2011-05-01

    Electrochemical oxidation has been proposed for the elimination of pesticides, pharmaceuticals and other organic micropollutants from complex waste streams. However, the detrimental effect of halide ion mediators and the generation of halogenated by-products in this process have largely been neglected thus far. In this study, we investigated the electrochemical oxidation pathways of the β-blocker metoprolol in reverse osmosis concentrate (ROC) from a water reclamation plant using titanium anodes coated with Ru(0.7)Ir(0.3)O(2) or SnO(2)-Sb metal oxide layers. The results of liquid chromatography-mass spectrometry analysis indicated that irrespective of the electrode coating the same oxidant species participated in electrochemical transformation of metoprolol in ROC. Although Ti/SnO(2)-Sb exhibited higher oxidizing power for the same applied specific electrical charge, the generation of large fractions of chloro-, chloro-bromo- and bromo derivatives was observed for both electrode coatings. However, degradation rates of metoprolol and its degradation products were generally higher for the Ti/SnO(2)-Sb anode. Chemical analyses of metoprolol and its by-products were complemented with bioanalytical tools in order to investigate their toxicity relative to the parent compound. Results of the bioluminescence inhibition test with Vibrio fischeri and the combined algae test with Pseudokirchneriella subcapitata indicated a substantial increase in non-specific toxicity of the reaction mixture due to the formed halogenated by-products, while the specific toxicity (inhibition of photosynthesis) remained unchanged. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. DFT Simulation of Structural and Optical Properties of 9-Aminoacridine Half-Sandwich Ru(II), Rh(III), and Ir(III) Antitumoral Complexes and Their Interaction with DNA.

    Science.gov (United States)

    Cerón-Carrasco, José Pedro; Ruiz, José; Vicente, Consuelo; de Haro, Concepción; Bautista, Delia; Zúñiga, José; Requena, Alberto

    2017-08-08

    In this work, we use DFT-based methods to simulate the chemical structures, optical properties, and interaction with DNA of a recently synthesized chelated C^N 9-aminoacridine arene Ru(II) anticancer agent and two new closely related Rh(III) and Ir(III) complexes using DFT-based methods. Four chemical models and a number of theoretical approaches, which representatively include the PBE0, B97D, ωB97X, ωB97X-D, M06, and M06-L density functionals and the LANL2DZ, def2-SVP, and def2-TZVP basis sets, are tested. The best overall accuracy/cost performance for the optimization process is reached at the ωB97X-D/def2-SVP and M06/def2-SVP levels of theory. Inclusion of explicit solvent molecules (CHCl3) further refines the geometry, while taking into account the crystal network gives no significant improvements of the computed bond distances and angles. The analysis of the excited states reveals that the M06 level matches better the experimental absorption spectra, compared to ωB97X-D. The use of the M06/def2-SVP approach is therefore a well-balanced method to study theoretically the bioactivity of this type of antitumoral complexes, so we couple this TD-DFT approach to molecular dynamics simulations in order to assess their reactivity with DNA. The reported results demonstrate that these drugs could be used to inject electrons into DNA, which might broaden their applications in photoactivated chemotherapy and as new materials for DNA-based electrochemical nanodevices.

  5. PVP/Pd/IrO2/Nafion修饰微电极用于成纤维细胞中一氧化氮释放的研究%Direct Monitoring of Nitric Oxide Release from Fibrocytes with PVP/Pd/IrO2/Nafion Chemically Modified Microelectrode

    Institute of Scientific and Technical Information of China (English)

    鲜跃仲; 徐继明; 陆嘉星; 刘梅川; 蔡琪; 金利通

    2002-01-01

    采用PVP/Pd/IrO2/Nafion修饰电极对成纤维细胞中NO的释放情况进行了研究.结果表明,在正常状态下,采用NO前体L-精氨酸和乙酰胆碱对成纤维细胞进行刺激后没有NO的释放;当用脂多糖进行诱导后,则释放出高浓度的NO,加入L-精氨酸和乙酰胆碱都促进了NO的合成,而L-NNA的加入则逆转了L-精氨酸和乙酰胆碱的作用.

  6. Evaluation of Bi as internal standard to minimize matrix effects on the direct determination of Pb in vinegar by graphite furnace atomic absorption spectrometry using Ru permanent modifier with co-injection of Pd/Mg(NO 3) 2

    Science.gov (United States)

    de Oliveira, Silvana Ruella; Neto, José Anchieta Gomes

    2007-09-01

    Bismuth was evaluated as an internal standard for the direct determination of Pb in vinegar by graphite furnace atomic absorption spectrometry using Ru as a permanent modifier with co-injection of Pd/Mg(NO 3) 2. The correlation coefficient of the graph plotted from the normalized absorbance signals of Bi versus Pb was r = 0.989. Matrix effects were evaluated by analyzing the slope ratios between the analytical curve obtained from reference solutions prepared in 0.2% (v/v) HNO 3 and analytical curves obtained from Pb additions in red and white wine vinegar samples. The calculated ratios were around 1.04 and 1.02 for analytical curves established applying an internal standard and 1.3 and 1.5 for analytical curves without. Analytical curves in the 2.5-15 μg L - 1 Pb concentration interval were established using the ratio Pb absorbance to Bi absorbance versus analyte concentration, and typical linear correlations of r = 0.999 were obtained. The proposed method was applied for direct determination of Pb in 18 commercial vinegar samples and the Pb concentration varied from 2.6 to 31 μg L - 1 . Results were in agreement at a 95% confidence level (paired t-test) with those obtained for digested samples. Recoveries of Pb added to vinegars varied from 96 to 108% with and from 72 to 86% without an internal standard. Two water standard reference materials diluted in vinegar sample were also analyzed and results were in agreement with certified values at a 95% confidence level. The characteristic mass was 40 pg Pb and the useful lifetime of the tube was around 1600 firings. The limit of detection was 0.3 μg L - 1 and the relative standard deviation was ≤ 3.8% and ≤ 8.3% ( n = 12) for a sample containing 10 μg L - 1 Pb with and without internal standard, respectively.

  7. X = Pt, Os, Ru, Ir, Rh

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Department of Physics, Federal University of Technology, Akure. Nigeria. ... All structure relaxation and bulk modulus ... using the Sutton-Chen form of Embedded Atom ... In (1) - (3), c is a dimensionless quantity, r is the ij spacing ... to the large numbers of atoms involved, cubic ... in the theoretical prediction of hard materials.

  8. London penetration depth measurements in Ba (Fe1-xTx)2As2(T=Co,Ni,Ru,Rh,Pd,Pt,Co+Cu) superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Ryan T. [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The London penetration depth has been measured in various doping levels of single crystals of Ba(Fe1-xTx)2As2 (T=Co,Ni,Ru,Rh,Pd,Pt,Co+Cu) superconductors by utilizing a tunnel diode resonator (TDR) apparatus. All in-plane penetration depth measurements exhibit a power law temperature dependence of the form Δλab(T) = CTn, indicating the existence of low-temperature, normal state quasiparticles all the way down to the lowest measured temperature, which was typically 500 mK. Several different doping concentrations from the Ba(Fe1-xTx)2As2 (T=Co,Ni) systems have been measured and the doping dependence of the power law exponent, n, is compared to results from measurements of thermal conductivity and specific heat. In addition, a novel method has been developed to allow for the measurement of the zero temperature value of the in-plane penetration depth, λab(0), by using TDR frequency shifts. By using this technique, the doping dependence of λab(0) has been measured in the Ba(Fe1-xCox)2As2 series, which has allowed also for the construction of the doping-dependent superfluid phase stiffness, ρs(T) = [λ(0)/λ(T)]2. By studying the effects of disorder on these superconductors using heavy ion irradiation, it has been determined that the observed power law temperature dependence likely arises from pair-breaking impurity scattering contributions, which is consistent with the proposed s±-wave symmetry of the superconducting gap in the dirty scattering limit. This hypothesis is supported by the measurement of an exponential temperature dependence of the penetration depth in the intrinsically clean LiFeAs, indicative of a nodeless superconducting gap.

  9. Effect of pH on the Nitrite Hydrogenation Mechanism over Pd/Al2O3 and Pt/Al2O3: Details Obtained with ATR-IR Spectroscopy

    DEFF Research Database (Denmark)

    Ebbesen, Sune Dalgaard; Mojet, Barbara L.; Lefferts, Leon

    2011-01-01

    It is well-known that activity and selectivity to N2 during nitrite hydrogenation over noble metal catalysts in water depend on the pH of the solution, but mechanistic understanding is lacking. Attenuated total reflection infrared (ATR-IR) spectroscopy is an ideal tool to perform detailed studies...... on catalytic surfaces in water. In this paper, the influence of pH was studied on adsorption and subsequent hydrogenation of nitrite in water between pH 5 and 9 over Pd/Al2O3 and Pt/Al2O3, using ATR-IR spectroscopy. On both catalysts, pH clearly influenced the surface coverage and reaction rates...

  10. Atomistic modeling of ternary additions to NiTi and quaternary additions to Ni-Ti-Pd, Ni-Ti-Pt and Ni-Ti-Hf shape memory alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mosca, H.O., E-mail: hmosca@cnea.gov.ar [Gcia. Investigacion y Aplicaciones, CNEA, Av. Gral Paz 1499, B1650KNA San Martin (Argentina); GCMM, UTN, FRG Pacheco, Av. H. Yrigoyen 288, Gral. Pacheco (Argentina); Bozzolo, G. [Loyola University Maryland, 4501 N. Charles St., Baltimore, MD 21210 (United States); Grosso, M.F. del [Gcia. Investigacion y Aplicaciones, CNEA, Av. Gral Paz 1499, B1650KNA San Martin (Argentina); GCMM, UTN, FRG Pacheco, Av. H. Yrigoyen 288, Gral. Pacheco (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET (Argentina)

    2012-08-15

    The behavior of ternary and quaternary additions to NiTi shape memory alloys is investigated using a quantum approximate method for the energetics. Ternary additions X to NiTi and quaternary additions to Ni-Ti-Pd, Ni-Ti-Pt, and Ni-Ti-Hf alloys, for X=Au, Pt, Ir, Os, Re, W, Ta,Ag, Pd, Rh, Ru, Tc, Mo, Nb, Zr, Zn, Cu, Co, Fe, Mn, V, Sc, Si, Al and Mg are considered. Bulk properties such as lattice parameter, energy of formation, and bulk modulus of the B2 alloys are studied for variations due to the presence of one or two simultaneous additives.

  11. Microwave irradiation for the facile synthesis of transition-metal nanoparticles (NPs) in ionic liquids (ILs) from metal-carbonyl precursors and Ru-, Rh-, and Ir-NP/IL dispersions as biphasic liquid-liquid hydrogenation nanocatalysts for cyclohexene.

    Science.gov (United States)

    Vollmer, Christian; Redel, Engelbert; Abu-Shandi, Khalid; Thomann, Ralf; Manyar, Haresh; Hardacre, Christopher; Janiak, Christoph

    2010-03-22

    Stable chromium, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, and iridium metal nanoparticles (M-NPs) have been reproducibly obtained by facile, rapid (3 min), and energy-saving 10 W microwave irradiation (MWI) under an argon atmosphere from their metal-carbonyl precursors [M(x)(CO)(y)] in the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF(4)]). This MWI synthesis is compared to UV-photolytic (1000 W, 15 min) or conventional thermal decomposition (180-250 degrees C, 6-12 h) of [M(x)(CO)(y)] in ILs. The MWI-obtained nanoparticles have a very small (IL dispersions (characterization by transmission electron microscopy (TEM), transmission electron diffraction (TED), and dynamic light scattering (DLS)). The ruthenium, rhodium, or iridium nanoparticle/IL dispersions are highly active and easily recyclable catalysts for the biphasic liquid-liquid hydrogenation of cyclohexene to cyclohexane with activities of up to 522 (mol product) (mol Ru)(-1) h(-1) and 884 (mol product) (mol Rh)(-1) h(-1) and give almost quantitative conversion within 2 h at 10 bar H(2) and 90 degrees C. Catalyst poisoning experiments with CS(2) (0.05 equiv per Ru) suggest a heterogeneous surface catalysis of Ru-NPs.

  12. Durable pd-based alloy and hydrogen generation membrane thereof

    Science.gov (United States)

    Benn, Raymond C.; Opalka, Susanne M.; Vanderspurt, Thomas Henry

    2010-02-02

    A durable Pd-based alloy is used for a H.sub.2-selective membrane in a hydrogen generator, as in the fuel processor of a fuel cell plant. The Pd-based alloy includes Cu as a binary element, and further includes "X", where "X" comprises at least one metal from group "M" that is BCC and acts to stabilize the .beta. BCC phase for stability during operating temperatures. The metal from group "M" is selected from the group consisting of Fe, Cr, Nb, Ta, V, Mo, and W, with Nb and Ta being most preferred. "X" may further comprise at least one metal from a group "N" that is non-BCC, preferably FCC, that enhances other properties of the membrane, such as ductility. The metal from group "N" is selected from the group consisting of Ag, Au, Re, Ru, Rh, Y, Ce, Ni, Ir, Pt, Co, La and In. The at. % of Pd in the binary Pd--Cu alloy ranges from about 35 at. % to about 55 at. %, and the at. % of "X" in the higher order alloy, based on said binary alloy, is in the range of about 1 at. % to about 15 at. %. The metals are selected according to a novel process.

  13. Enhanced interlayer exchange coupling in antiferromagnetically coupled ultrathin (Co70Fe30/Pd) multilayers

    Science.gov (United States)

    Meng, Zhaoliang; Qiu, Jinjun; Han, Guchang; Teo, Kie Leong

    2015-12-01

    We report the studies of magnetization reversal and magnetic interlayer coupling in synthetic antiferromagnetic (SAF) [Pd/Co70Fe30]9/Ru(tRu)/Pd(tPd)/[Co70Fe30/Pd]9 structure as functions of inserted Pd layer (tPd) and Ru layer (tRu) thicknesses. We found the exchange coupling field (Hex) and perpendicular magnetic anisotropy (PMA) can be controlled by both the tPd and tRu, The Hex shows a Ruderman-Kittel-Kasuya-Yosida-type oscillatory decay dependence on tRu and a maximum interlayer coupling strength Jex = 0.522 erg/cm2 is achieved at tPd + tRu ≈ 0.8 nm in the as-deposited sample. As it is known that a high post-annealing stability of SAF structure is required for magnetic random access memory applications, the dependence of Hex and PMA on the post-annealing temperature (Ta) is also investigated. We found that both high PMA of the top Co70Fe30/Pd multilayer is maintained and Hex is enhanced with increasing Ta up to 350 °C for tRu > 0.7 nm in our SAF structure.

  14. Casting of MOD inlay using rings with holes on both sides: 12∼18 wt%Au-20∼26Pd-14.48∼26.48Cu-40Ag-1.5Zn-0.02Ir alloys.

    Science.gov (United States)

    Ohkuma, Kazuo; Kazama, Miku; Ogura, Hideo

    2012-01-01

    Using a casting ring with openings on both sides and a water-absorbent polymer, heterogeneity is maintained in a single casting and a precise MOD inlay can be produced. We produced 9 different kinds of gold-silver-palladium (Au-Ag-Pd) alloys by changing the ratio of palladium, gold, and copper and investing them, and changing parameters such as the angulation of the casting ring openings and the water:powder ratios to produce MOD inlay castings. We measured the expansion and shrinkage percentage of the castings in both the buccolingual and mesiodistal directions. From this experiment, we learned that precise MOD inlay castings can be produced using rings with 240° openings when invested in a thick mix having a standard water:powder ratio or using rings with 200° openings when invested in a thick mix having a water:powder ratio for a 12 wt%Au-20∼26Pd-20.48∼26.48Cu-40Ag-1.5Zn-0.02Ir alloyes.

  15. Stopping the growth of particles to silica-supported mono-nuclear Ru hydride surface species by tuning silica with surface silanes

    Energy Technology Data Exchange (ETDEWEB)

    Berthoud, Romain; Fenet, Bernard; Lukens, Wayne; Pelzer, Katrin; Basset, Jean-Marie; Candy, Jean-Pierre; Coperet, Christophe

    2007-07-11

    Tuning silica by replacing surface silanols with silanes allows chemical grafting of Ru(COD)(COT) through a covalent Ru-Si bond, as evidenced by elemental analysis, IR spectroscopy and EXAFS. Treatment of these surface species under H2 at 300 oC yields a mononuclear Ru hydride species, without any sintering of the metal according to TEM and EXAFS analyses. This supported system displays catalytic properties different from those of supported Ru particles (2 nm), selectively hydrogenating olefins over aromatics.

  16. Enhanced thermoelectric power and electronic correlations in RuSe2

    Science.gov (United States)

    Wang, Kefeng; Wang, Aifeng; Tomic, A.; Wang, Limin; Abeykoon, A. M. Milinda; Dooryhee, E.; Billinge, S. J. L.; Petrovic, C.

    2015-04-01

    We report the electronic structure, electric and thermal transport properties of Ru1-xIrxSe2 (x ≤ 0.2). RuSe2 is a semiconductor that crystallizes in a cubic pyrite unit cell. The Seebeck coefficient of RuSe2 exceeds -200 μV/K around 730 K. Ir substitution results in the suppression of the resistivity and the Seebeck coefficient, suggesting the removal of the peaks in density of states near the Fermi level. Ru0.8Ir0.2Se2 shows a semiconductor-metal crossover at about 30 K. The magnetic field restores the semiconducting behavior. Our results indicate the importance of the electronic correlations in enhanced thermoelectricity of RuSb2.

  17. Enhanced thermoelectric power and electronic correlations in RuSe2

    Directory of Open Access Journals (Sweden)

    Kefeng Wang

    2015-04-01

    Full Text Available We report the electronic structure, electric and thermal transport properties of Ru1−xIrxSe2 (x ≤ 0.2. RuSe2 is a semiconductor that crystallizes in a cubic pyrite unit cell. The Seebeck coefficient of RuSe2 exceeds −200 μV/K around 730 K. Ir substitution results in the suppression of the resistivity and the Seebeck coefficient, suggesting the removal of the peaks in density of states near the Fermi level. Ru0.8Ir0.2Se2 shows a semiconductor-metal crossover at about 30 K. The magnetic field restores the semiconducting behavior. Our results indicate the importance of the electronic correlations in enhanced thermoelectricity of RuSb2.

  18. 微波消解-双浊点萃取 ICP -MS 测定地球化学样品中的痕量铂钯钌铑%Determination of Pt,Pd,Ru,Rh in Geochemical Samples by ICP-MS with Microwave Digestion and Dual-cloud Point Extraction

    Institute of Scientific and Technical Information of China (English)

    沈宇; 张尼; 高小红; 李展; 李日升; 郑建斌

    2016-01-01

    Traditional cloud point extraction methods commonly enrich elements in the viscous surfactant. However,the viscosity of the solution will adversely affect the detection signal of the plasma.Harmful agents such as methanol are usually adopted as a thinner to reduce the viscosity of the organic phase,but the organic component affects the stability of the plasma,and organic absorption on the injection tube will enhance elemental memory effect.These disadvantages limit the widespread application of Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)in cloud point extraction.A method to determine Pt,Pd,Ru, Rh in geochemical samples by ICP-MS based dual-cloud point extraction has been established,and is reported in this paper.After the microwave digestion procedure,first cloud point extraction is performed on the sample solution using DDTP as the sequestrant and Triton X-114 as the surfactant.HNO3 is added into the organic phase,and second cloud point extraction is performed by heating so that Pt,Pd,Ru,Rh enter the water phase from the organic phase. Enrichment factors are 45,33,18,35,and detection limits are 0.05,0.02,0.10 and 0.03 μg/L for Pt,Pd,Ru and Rh,respectively.The proposed method succeeds in the simultaneous enrichment of trace platinum group elements in complex matrix geochemical samples,improving the stability of the ICP-MS measurement.%传统浊点萃取技术是将待测元素富集在黏稠的表面活性剂相中,溶液的黏度会对等离子体检测信号产生影响,通常使用甲醇作为稀释剂降低有机相黏度,有机成分也对等离子体的稳定性产生影响,同时有机物在进样管路上的吸附还会提高待测元素的记忆效应,因而限制了 ICP -MS 在浊点萃取中的应用。本文建立了双浊点萃取技术 ICP -MS 测定地球化学样品中铂钯钌铑的分析方法。样品用微波消解处理后,以DDTP 为螯合剂,Triton X -114为表面活性剂,对消解溶液第一次浊点萃取

  19. Atšķirības sieviešu ar augstu un zemu ķermeņa pašvērtējumu spriedumos par sabiedrībā populāru sieviešu ķermeņa izmēriem.

    OpenAIRE

    Kalniņa, Aija

    2009-01-01

    Pētījuma mērķis bija noskaidrot, vai pastāv atšķirības ar savu ķermeni neapmierinātu sieviešu un ar savu ķermeni apmierinātu sieviešu spriedumos par sabiedrībā populāru un medijos bieži redzamu sieviešu ķermeņu izmēriem. Pētījumā piedalījās divas izlases grupas: vienā bija 24 sievietes ar augstu ķermeņa pašvērtējumu, otrā – 25 sievietes ar zemu ķermeņa pašvērtējumu. Sievietes bija vecumā no 18 līdz 25 gadiem, kuru ķermeņa masas indekss (ĶMI) iekļaujas normālos rādītājos, un kurām nav ēšana...

  20. Conversion of biomass-derived sorbitol to glycols over carbon-materials supported Ru-based catalysts

    Science.gov (United States)

    Guo, Xingcui; Guan, Jing; Li, Bin; Wang, Xicheng; Mu, Xindong; Liu, Huizhou

    2015-11-01

    Ruthenium (Ru) supported on activated carbon (AC) and carbon nanotubes (CNTs) was carried out in the hydrogenolysis of sorbitol to ethylene glycol (EG) and 1,2-propanediol (1,2-PD) under the promotion of tungsten (WOx) species and different bases. Their catalytic activities and glycols selectivities strongly depended on the support properties and location of Ru on CNTs, owning to the altered metal-support interactions and electronic state of ruthenium. Ru located outside of the tubes showed excellent catalytic performance than those encapsulated inside the nanotubes. Additionally, the introduction of WOx into Ru/CNTs significantly improved the hydrogenolysis activities, and a complete conversion of sorbitol with up to 60.2% 1,2-PD and EG yields was obtained on RuWOx/CNTs catalyst upon addition of Ca(OH)2. Stability study showed that this catalyst was highly stable against leaching and poisoning and could be recycled several times.

  1. IR intensity

    DEFF Research Database (Denmark)

    Spanget-Larsen, Jens

    2015-01-01

    Definitions, formulas, and code for producing epsilon values (molar absorption coefficients) and IR spectral curve from 'Gaussian' FREQ output.......Definitions, formulas, and code for producing epsilon values (molar absorption coefficients) and IR spectral curve from 'Gaussian' FREQ output....

  2. High energy conformers of M(+)(APE)(H2O)(0-1)Ar(0-1) clusters revealed by combined IR-PD and DFT-MD anharmonic vibrational spectroscopy.

    Science.gov (United States)

    Brites, V; Nicely, A L; Sieffert, N; Gaigeot, M-P; Lisy, J M

    2014-07-14

    IR-PD vibrational spectroscopy and DFT-based molecular dynamics simulations are combined in order to unravel the structures of M(+)(APE)(H2O)0-1 ionic clusters (M = Na, K), where APE (2-amino-1-phenyl ethanol) is commonly used as an analogue for the noradrenaline neurotransmitter. The strength of the synergy between experiments and simulations presented here is that DFT-MD provides anharmonic vibrational spectra that unambiguously help assign the ionic clusters structures. Depending on the interacting cation, we have found that the lowest energy conformers of K(+)(APE)(H2O)0-1 clusters are formed, while the lowest energy conformers of Na(+)(APE)(H2O)0-1 clusters can only be observed through water loss channel (i.e. without argon tagged to the clusters). Trapping of higher energy conformers is observed when the argon loss channel is recorded in the experiment. This has been rationalized by transition state energies. The dynamical anharmonic vibrational spectra unambiguously provide the prominent OH stretch due to the OH···NH2 H-bond, within 10 cm(-1) of the experiment, hence reproducing the 240-300 cm(-1) red-shift (depending on the interacting cation) from bare neutral APE. When this H-bond is not present, the dynamical anharmonic spectra provide the water O-H stretches as well as the rotational motion of the water molecule at finite temperature, as observed in the experiment.

  3. RU28318, an Aldosterone Antagonist, in Combination with an ACE Inhibitor and Angiotensin Receptor Blocker Attenuates Cardiac Dysfunction in Diabetes

    Directory of Open Access Journals (Sweden)

    Ibrahim F. Benter

    2013-01-01

    Full Text Available Aims. We evaluated the effects of RU28318 (RU, a selective mineralocorticoid receptor (MR antagonist, Captopril (Capt, an angiotensin converting enzyme inhibitor, and Losartan (Los, an angiotensin receptor blocker, alone or in combination with ischemia/reperfusion- (I/R- induced cardiac dysfunction in hearts obtained from normal and diabetic rats. Methods. Isolated hearts were perfused for 30 min and then subjected to 30 min of global ischemia (I followed by a period of 30 min of reperfusion (R. Drugs were administered for 30 min either before or after ischemia. Drug regimens tested were RU, Capt, Los, RU + Capt, RU + Los, Capt + Los, and RU + Capt + Los (Triple. Recovery of cardiac hemodynamics was evaluated. Results. Recovery of cardiac function was up to 5-fold worse in hearts obtained from diabetic animals compared to controls. Treatment with RU was generally better in preventing or reversing ischemia-induced cardiac dysfunction in normal hearts compared to treatment with Capt or Los alone. In diabetic hearts, RU was generally similarly effective as Capt or Los treatment. Conclusions. RU treatment locally might be considered as an effective therapy or preventative measure in cardiac I/R injury. Importantly, RU was the most effective at improving -dP/dt (a measure of diastolic function when administered to diabetic hearts after ischemia.

  4. Many metals make the cut: quaternary rare-earth germanides RE4M2InGe4 (M = Fe, Co, Ni, Ru, Rh, Ir) and RE4RhInGe4 derived from excision of slabs in RE2InGe2.

    Science.gov (United States)

    Oliynyk, Anton O; Stoyko, Stanislav S; Mar, Arthur

    2015-03-16

    The formation of quaternary rare-earth (RE) germanides containing transition metals (M's) from groups 6 to 10 was investigated through arc-melting and annealing reactions at 800 °C; about 50 new compounds were obtained. These include several new series of quaternary germanides RE4M2InGe4 (M = Fe, Co, Ru, Rh, Ir), previously known only for M = Mn and Ni; additional members of RE4Ni2InGe4 extended to other RE substituents; and a different but closely related series RE4RhInGe4. Detailed crystal structures were determined by single-crystal X-ray diffraction studies for 20 compounds. Monoclinic structures in space group C2/m are adopted by RE4M2InGe4 (Ho4Ni2InGe4-type, a = 15.1-16.5 Å, b = 4.1-4.4 Å, c = 6.9-7.3 Å, β = 106.2-108.6°) and RE4RhInGe4 (own type, a = 20.0-20.2 Å, b = 4.2-4.3 Å, c = 10.1-10.2 Å, β = 105.0-105.3°). Both structures contain frameworks built from MGe4 tetrahedra, InGe4 square planes, and Ge2 dimers, delimiting tunnels occupied by RE atoms. These structures can also be derived by cutting slabs along different directions from the more symmetrical RE2InGe2 structure. Although the Ge2 dimers are relatively invariant, the InGe4 square planes can undergo distortion to form two sets of short versus long In-Ge distances. This distortion results from a competition between M-Ge bonding in the MGe4 tetrahedra and In-Ge bonding in the InGe4 square planes.

  5. A Synthetic Pseudo-Rh: NOx Reduction Activity and Electronic Structure of Pd–Ru Solid-solution Alloy Nanoparticles

    Science.gov (United States)

    Sato, Katsutoshi; Tomonaga, Hiroyuki; Yamamoto, Tomokazu; Matsumura, Syo; Zulkifli, Nor Diana Binti; Ishimoto, Takayoshi; Koyama, Michihisa; Kusada, Kohei; Kobayashi, Hirokazu; Kitagawa, Hiroshi; Nagaoka, Katsutoshi

    2016-06-01

    Rh is one of the most important noble metals for industrial applications. A major fraction of Rh is used as a catalyst for emission control in automotive catalytic converters because of its unparalleled activity toward NOx reduction. However, Rh is a rare and extremely expensive element; thus, the development of Rh alternative composed of abundant elements is desirable. Pd and Ru are located at the right and left of Rh in the periodic table, respectively, nevertheless this combination of elements is immiscible in the bulk state. Here, we report a Pd–Ru solid-solution-alloy nanoparticle (PdxRu1-x NP) catalyst exhibiting better NOx reduction activity than Rh. Theoretical calculations show that the electronic structure of Pd0.5Ru0.5 is similar to that of Rh, indicating that Pd0.5Ru0.5 can be regarded as a pseudo-Rh. Pd0.5Ru0.5 exhibits better activity than natural Rh, which implies promising applications not only for exhaust-gas cleaning but also for various chemical reactions.

  6. Degradation mechanism of diethyl phthalate with electrogenerated hydroxyl radical on a Pd/C gas-diffusion electrode

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hui, E-mail: wanghui616@gmail.com [College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083 (China); Sun Dezi [College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083 (China); Bian Zhaoyng, E-mail: bzy@mail.ipc.ac.cn [Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2010-08-15

    Using a self-made Pd/C gas-diffusion electrode as the cathode and a Ti/IrO{sub 2}/RuO{sub 2} anode, the degradation of diethyl phthalate (DEP) has been investigated in an undivided electrolysis device by electrochemical oxidation processes. Hydroxyl radical (HO{center_dot}) was determined in the reaction mixture by the electron spin resonance spectrum (ESR). The result indicated that the Pd/C catalyst in Pd/C gas-diffusion electrode system accelerated the two-electron reduction of fed O{sub 2} to H{sub 2}O{sub 2}, which is in favor of producing HO{center_dot}. Additionally, the percentage removal of DEP and COD reached about 80.9 and 40.2% after 9 h electrolysis, respectively. It suggested that most of DEP were oxidized to intermediates using the Pd/C gas-diffusion electrode. Furthermore, the ratio of BOD{sub 5}/COD of resulted solutions was three times larger than the initial ones. Hence, the electrochemical oxidation enhanced the biodegradation character of the DEP solution. Finally, main aromatic intermediates (e.g., monoethyl phthalate (MEP) and phthalic acid (PA)) and main aliphatic carboxylic intermediates (e.g., formic, mesoxalic, oxalic, malonic, succinic, maleic, dodecanoic, and hexadecanoic acids) were identified by GC-MS. Moreover, a reaction scheme involving all these intermediates was proposed.

  7. Degradation mechanism of diethyl phthalate with electrogenerated hydroxyl radical on a Pd/C gas-diffusion electrode.

    Science.gov (United States)

    Wang, Hui; Sun, De-Zhi; Bian, Zhao-Yong

    2010-08-15

    Using a self-made Pd/C gas-diffusion electrode as the cathode and a Ti/IrO(2)/RuO(2) anode, the degradation of diethyl phthalate (DEP) has been investigated in an undivided electrolysis device by electrochemical oxidation processes. Hydroxyl radical (HO) was determined in the reaction mixture by the electron spin resonance spectrum (ESR). The result indicated that the Pd/C catalyst in Pd/C gas-diffusion electrode system accelerated the two-electron reduction of fed O(2) to H(2)O(2), which is in favor of producing HO. Additionally, the percentage removal of DEP and COD reached about 80.9 and 40.2% after 9h electrolysis, respectively. It suggested that most of DEP were oxidized to intermediates using the Pd/C gas-diffusion electrode. Furthermore, the ratio of BOD(5)/COD of resulted solutions was three times larger than the initial ones. Hence, the electrochemical oxidation enhanced the biodegradation character of the DEP solution. Finally, main aromatic intermediates (e.g., monoethyl phthalate (MEP) and phthalic acid (PA)) and main aliphatic carboxylic intermediates (e.g., formic, mesoxalic, oxalic, malonic, succinic, maleic, dodecanoic, and hexadecanoic acids) were identified by GC-MS. Moreover, a reaction scheme involving all these intermediates was proposed. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Nitrogen Scattering at Ru Surfaces

    NARCIS (Netherlands)

    Zaharia, T.; Ueta, H.; Kleyn, A.W.; Gleeson, M.A.

    2013-01-01

    Results on the scattering of hyperthermal N2 molecules from bare and N-covered Ru(0001) surfaces are presented. These are compared with Ar scattering from the same surfaces as a reference nonreactive system. In the case of bare Ru(0001) the measured angular distributions are consistent with scatteri

  9. Nitrogen Scattering at Ru Surfaces

    NARCIS (Netherlands)

    Zaharia, T.; Ueta, H.; Kleyn, A. W.; Gleeson, M. A.

    2013-01-01

    Results on the scattering of hyperthermal N2 molecules from bare and N-covered Ru(0001) surfaces are presented. These are compared with Ar scattering from the same surfaces as a reference non-reactive system. In the case of bare Ru(0001) the measured angular distributions are consistent with scatter

  10. Nitrogen Scattering at Ru Surfaces

    NARCIS (Netherlands)

    Zaharia, T.; Ueta, H.; Kleyn, A.W.; Gleeson, M.A.

    2013-01-01

    Results on the scattering of hyperthermal N-2 molecules from bare and N-covered Ru(0001) surfaces are presented. These are compared with Ar scattering from the same surfaces as a reference non-reactive system. In the case of bare Ru(0001) the measured angular distributions are consistent with scatte

  11. Reactions of ethanol on Ru

    NARCIS (Netherlands)

    Sturm, Jacobus Marinus; Liu, Feng; Lee, Christopher James; Bijkerk, Frederik

    2012-01-01

    The adsorption and reactions of ethanol on Ru(0001) were studied with temperatureprogrammed desorption (TPD) and reflection-absorption infrared spectroscopy (RAIRS). Ethanol was found to adsorb intact onto Ru(0001) below 100 K. Heating to 250 K resulted in formation of ethoxy groups, which undergo

  12. Formation and nitrile hydrogenation performance of Ru nanoparticles on a K-doped Al2O3 surface.

    Science.gov (United States)

    Muratsugu, Satoshi; Kityakarn, Sutasinee; Wang, Fei; Ishiguro, Nozomu; Kamachi, Takashi; Yoshizawa, Kazunari; Sekizawa, Oki; Uruga, Tomoya; Tada, Mizuki

    2015-10-14

    Decarbonylation-promoted Ru nanoparticle formation from Ru3(CO)12 on a basic K-doped Al2O3 surface was investigated by in situ FT-IR and in situ XAFS. Supported Ru3(CO)12 clusters on K-doped Al2O3 were converted stepwise to Ru nanoparticles, which catalyzed the selective hydrogenation of nitriles to the corresponding primary amines via initial decarbonylation, the nucleation of the Ru cluster core, and the growth of metallic Ru nanoparticles on the surface. As a result, small Ru nanoparticles, with an average diameter of less than 2 nm, were formed on the support and acted as efficient catalysts for nitrile hydrogenation at 343 K under hydrogen at atmospheric pressure. The structure and catalytic performance of Ru catalysts depended strongly on the type of oxide support, and the K-doped Al2O3 support acted as a good oxide for the selective nitrile hydrogenation without basic additives like ammonia. The activation of nitriles on the modelled Ru catalyst was also investigated by DFT calculations, and the adsorption structure of a nitrene-like intermediate, which was favourable for high primary amine selectivity, was the most stable structure on Ru compared with other intermediate structures.

  13. Preparation and Nonlinearity properties of Pd Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Pd nanoparticles less than 8 nm were photoinduced by a near-IR femtosecond laser. The sign of the refraction nonlinearity is negative for the Pd nanoparticles with TiO2, while it is positive for those without TiO2.

  14. Geochemistry and mineralogy of Pd in the magnetitite layer within the upper gabbro of the Mesoarchean Nuasahi Massif (Orissa, India)

    Science.gov (United States)

    Prichard, Hazel M.; Mondal, Sisir K.; Mukherjee, Ria; Fisher, Peter C.; Giles, Nicolas

    2017-07-01

    Palladium concentrations of 1-3 ppm with an average Pt/Pd ratio of 0.15 have been located for the first time in a magnetitite layer in the Nuasahi Massif in Orissa India. This layer occurs at a high stratigraphic level in the complex and is nearly 4-km long and 5-12-m thick. The sections of the Pd-rich zone identified to date extend over a distance of 1 km at the southern end of the layer. Several phases of mineralization are evident. The first, primary assemblage of platinum-group minerals (PGM) contains Pd-sulfides (vysotskite), Pd-Pb alloys (zvyagintsevite), and a Pd-In alloy, a mineral probably new to mineralogy. These PGM are confined to central magnetite grains in the magnetitites. The magnetite grains with exsolved fine laths of ilmenite at centers are referred to as central magnetite grains. These central magnetite grains are commonly surrounded by blebs of ilmenite and magnetite that contain the majority of the PGM. These are dominated by Pd-antimonides, variably altered to Pd-oxides, and other PGM including PtAs2 (sperrylite), RuS2 (laurite), and IrRhAsS (irarsite/hollingwothite). Many of these PGM also occur in the interstitial silicates, with rare occurrences in the central magnetite grains. We propose that the platinum-group elements (PGE) crystallized during a minor sulfide saturation event that occurred as the magnetitites crystallized. This event produced the minor Cu-sulfides in these magnetitites. Later introduction of antimony and arsenic, during the alteration event that produced the blebby ilmenite and magnetite, led to the more primary PGM being succeeded by the main PGM assemblage, dominated by Pd-antimonides. These are associated with secondary Cu minerals and sperrylite. Subsequent oxidation during weathering in the hot wet Indian climate produced the Pd-oxides. The Nuasahi Massif is a sill-like Archean layered ultramafic-mafic intrusion genetically linked to high-Mg siliceous basalt or boninites and is characterized by unusually thick

  15. Comparative analysis of deuterium ions implanted and deuterium atoms saturated at high pressure in pure pd and Pd diluted alloys

    Science.gov (United States)

    Didyk, A. Yu.; Kulikauskas, V. S.; Wiśniewski, R.; Wilczynska, T.; Kitowski, K.

    2012-01-01

    Pd and its diluted alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25 keV deuterium ions at a fluence interval of (1.2-2.3) × 1022 m-2. The same property alloys were saturated by deuterium atoms using high pressure chamber during long period with temperature stabilization and electrical resistance measurement of standard Pd wire. The post-treatment depth distributions of deuterium and accompanied hydrogen atoms were measured immediately after implantation (ten days) and after definite time period (three months) after saturation with the usage of elastic recoil detection analysis (ERDA). After two months, the measurements were repeated. The comparison of obtained results in both series of studies allowed one to make an important observation of a relative stability of deuterium and hydrogen atoms in pure Pd and its diluted alloys.

  16. Communication between remote moieties in linear Ru-Ru-Ru trimetallic cyanide-bridged complexes.

    Science.gov (United States)

    Pieslinger, German E; Albores, Pablo; Slep, Leonardo D; Coe, Benjamin J; Timpson, Cliff J; Baraldo, Luis M

    2013-03-18

    In this article, we report the structural, spectroscopic, and electrochemical properties of the cyanide-bridged complex salts trans-[(NC)Ru(II)(L)4(μ-CN)Ru(II)(py)4Cl]PF6 and trans-[Ru(II)(L)4{(μ-CN)Ru(II)(py)4Cl}2](PF6)2 (L = pyridine or 4-methoxypyridine). The mixed-valence forms of these compounds show a variety of metal-to-metal charge-transfer bands, including one arising from charge transfer between the remote ruthenium units. The latter is more intense when L = 4-methoxypyridine and points to the role of the bridging ruthenium unit in promoting mixing between the dπ orbitals of the terminal fragments.

  17. Degradation of 4-chlorophenol by the anodic-cathodic cooperative effect with a Pd/MWNT gas-diffusion electrode.

    Science.gov (United States)

    Wang, H; Wei, X J; Bian, Z Y

    2012-01-01

    Pd/multi-walled carbon nanotubes (MWNTs) catalyst used for the gas-diffusion electrode was prepared by ethylene glycol (EG) reduction and characterized by the X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicated that Pd particles with an average size of 8.0 nm were highly dispersed in the MWNTs with amorphous structure. In a diaphragm electrolysis system with a Ti/RuO(2)/IrO(2) anode and the Pd/MWNT gas diffusion cathode, the degradation of 4-chlorophenol was performed by a combination of electrochemical reduction and oxidation. The combined process was in favor of improving 4-chlorophenol degradation efficiency. The optimum reaction conditions were as following: initial pH 7, aeration with hydrogen and air. Under the optimized electrolysis conditions the removal of 4-chlorophenol in the anodic and cathodic compartments were 98.5 and 90.5%, respectively. Additionally, based on the analysis of electrolysis intermediates using high performance liquid chromatography (HPLC) and ion chromatography (IC), the electrolysis degradation of 4-chlorophenol was proposed containing the intermediates, such as phenol, hydroquinone, benzoquinone, maleic acid, fumaric acid, succinic acid, malonic acid, oxalic acid, acetic acid and formic acid.

  18. IRS organigram

    Science.gov (United States)

    Messerschmid, Ernst

    1991-01-01

    Charts and graphs relative to magnetoplasmadynamic (MPD) thruster technology are given. The research activities at the Institute of Space Transportation, University of Stuttgart, are summarized. Information is given on the Institute's Electric Propulsion and Plasma Wind Tunnel; thermal arcjet research; the nozzle-type thruster, DT-IRS; nozzle-type MPD thrusters; a hot anode thruster; the DT6 thruster; the ZT-1 thruster; the cylindrical MPD thruster; and a comparison of continuous and quasi-steady MPD.

  19. Determination of Pt,Pd,Ir and Au in Ores by Inductively Coupled Plasma Atomic Emission Spectrometry after Preconcentration by Minified Nickel Sulfide Fire Assay%硫化镍试金预富集-ICP-AES测定矿石中的Pt、Pd、Ir、Au

    Institute of Scientific and Technical Information of China (English)

    刘小荣; 董守安; 冯忠; 陈丁文

    2003-01-01

    The effect of various factors on the determination o f Pt,Pd,Ir and Au by ICP-AES was investigated in detail using minified nickel su lfide fire assay preconcentration.The results indicated that after the nickel su lfide bead was dissolved in HCl,filtering the solution by fritted glass crucible and dissolving the residue with HCl+H2O2 were a comparatively ideal analyti cal scheme.During the bead dissolving the losses of Pt and Pd were negligible,th e loss of Au was quite high,and the determination of Au was only semiqantitative .The average recoveries for Pt,Pd and Ir ranged from 96% to 99% for the determin ation of μg/g level,the relative standard derivation(RSD) was 1.7 %~6.8%(n=5).The proposed procedure has been applied to analyse o f ores and concentrates.%详细研究了硫化镍试金预富集-ICP-AES测定矿石中的P t、Pd、Ir、Au的多种影响因素.结果表明硫化镍扣用盐酸溶解,多孔玻砂坩埚过滤溶液, 盐酸和双氧水溶解残渣是比较理想的分析方案.硫化镍扣溶解过程中,Pt、Pd的损失可忽略 .Au的损失相当高,仅能半定量.对于μg/g级的样品,Pt、Pd、Ir、Au的平均回收率在96% ~99%之间,相对标准偏差为1.7%~6.8%(n=5).拟定的方法已用于矿石、精矿的分析.

  20. Growth of {110}-one-axis-oriented perovskite-type oxide films using self-aligned epitaxial (101)PdO//(111) Pd double layers

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Hiroki [Department of Innovative and Engineered Material, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kariya, Tetsuro [Department of Innovative and Engineered Material, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Sanyo Special Steel Co., Ltd, 3007, Nakashima, Shikama-ku, Himeji, Hyogo 672-8677 (Japan); Shimizu, Takao [Department of Innovative and Engineered Material, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan); Uchiyama, Kiyoshi, E-mail: uchiyama@tsuruoka-nct.ac.jp [Department of Creative Engineering, National Institute of Technology, Tsuruoka College, 104 Inooka Sawada, Tsuruoka, Yamagata 997-8511 (Japan); Funakubo, Hiroshi [Department of Innovative and Engineered Material, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8503 (Japan)

    2016-01-29

    Self-aligned (101)-one-axis-oriented PdO layer was obtained on (111) Pd films prepared on (111)Pt/TiO{sub x}/SiO{sub 2}/Si [abbreviated as (111)Pt/Si] substrates by the heat treatment at 750 °C under atmospheric oxygen flow. Films with (110){sub c}-oriented SrRuO{sub 3} with perovskite structure were successfully deposited at 500 °C on a (101)-oriented PdO layer by an RF magnetron sputtering method due to their relatively small lattice mismatch. A (101)-oriented Sr(Zr{sub 0.8}Y{sub 0.2})O{sub 3-δ} (SZYO) film can be successfully prepared on (110){sub c}-oriented SrRuO{sub 3} and its proton conductivity is almost the same as that of (111){sub c}-oriented SZYO but slightly smaller than that of (111){sub c}-oriented one. As the conductivity is strongly affected by the film crystallinity, we can conclude that the newly fabricated (110){sub c}-oriented SZYO has almost the same crystallinity comparing to the films with other orientation. We have successfully demonstrated that the use of (101)PdO//(111)Pd double layer is a good candidate to grow {110}-one-axis-oriented perovskite thin films on Si substrates. - Highlights: • Self-aligned (101)-one-axis-oriented PdO layer were obtained on (111) Pd films • (110){sub c}SrRuO{sub 3} perovskite can be deposited successfully on (101) PdO//Pd double layer • (101){sub c}Sr(Zr{sub 0.8}Y{sub 0.2})O{sub 3–δ} perovskite is also prepared by using (110){sub c} SrRuO{sub 3} layer • (101)PdO//(111)Pd is quite effective for growing {110}-oriented perovskite films.

  1. PD Lab

    NARCIS (Netherlands)

    Bilow, Marcel; Entrop, Alexis Gerardus; Lichtenberg, Jos; Stoutjesdijk, Pieter

    2015-01-01

    PD Lab explores the applications of building sector related product development. PD lab investigates and tests digital production technologies like CNC milled wood connections. It will also act as a platform in its wider meaning to investigate the effects and influences of file to factory

  2. Low-spin excitations in {sup 98}Ru

    Energy Technology Data Exchange (ETDEWEB)

    Radeck, Desiree; Albers, Michael; Bernards, Christian; Fransen, Christoph; Jolie, Jan; Muecher, Dennis [Institut fuer Kernphysik, Universitaet Koeln (Germany)

    2009-07-01

    In the context of collectivity in the A=100 mass region N=52 isotones were investigated in detail and phonon excitations - especially the mixed-symmetry (MS) states - were identified. In order to investigate how states with this MS character evolve with increasing valence neutron number N=54 isotones were studied. While in {sup 96}Mo the one-phonon MS state 2{sup +}{sub 1,ms} was identified, {sup 98}Ru shows a breakdown of vibrational structure above the two-phonon triplet and no candidate for the 2{sup +}{sub 1,ms} state was assigned. The recently investigated N=54 isotone {sup 100}Pd was explained well with an U{sub {pi}}{sub {nu}}(5) fit within the IBM-2. Furthermore, a candidate for the one-phonon MS2{sup +}{sub 1,ms} state was determined. To do further investigations on the N=54 isotone {sup 98}Ru - in particular regarding the breakdown of vibrational symmetry and the one-phonon MS excitation - an experiment was performed at the Cologne Tandem Accelerator using the HORUS spectrometer. The nuclei were populated by the reaction {sup 97}Mo({sup 3}He,2n){sup 98}Ru. By analysing the coincidence and {gamma}{gamma} angular correlation data the level scheme was extended and clarified by determining spins, multipole mixing ratios and branching ratios. The low-energy excitations of positive parity are discussed and compared to theoretical expectations. The results are compared with those for other N=54 isotones.

  3. Study on Selective Hydrogenation of Avermectin to Ivermectin over Ir/γ-Al2O3%负载金属催化剂Ir/γ-Al2O3对阿维菌素选择加氢反应研究

    Institute of Scientific and Technical Information of China (English)

    杨鹏; 樊光银; 马晓艳; 李瑞祥; 李贤均

    2007-01-01

    分别采用氢气、NaBH4、醇水混合溶剂还原,PVP(聚乙烯吡咯烷酮)保护和微乳液法制备了γ-Al2O3负载的Ir金属催化剂,通过XPS、XRD、TEM对催化剂的结构进行了表征,考察了催化剂对阿维菌素选择加氢制备伊维菌素的性能,探讨了催化剂制备方法对催化剂活性和选择性的影响.实验结果表明,在不同金属催化剂Ru/γ-Al2O3、Pd/γ-Al2O3、Pt/γ-Al2O3、Ir/γ-Al2O3中,Ir/γ-Al2O3的活性和选择性最好.用PVP保护的Ir/γ-Al2O3,其催化活性和选择性比没有PVP保护的催化剂有显著提高;采用微乳液法制备的Ir/γ-Al2O3催化剂显示出最好的活性,但反应选择性比PVP保护的催化剂差.

  4. Round table on RU486.

    Science.gov (United States)

    Shallat, L

    1993-01-01

    As a non-invasive means of early abortion, RU-486 has the potential to increase women's reproductive options; at the same time, the "abortion pill" has stimulated debate about the ethics and safety of new medical technologies. When combined with a prostaglandin (PG), the success rate for RU-486 is 96% for pregnancies of up to 9 weeks' gestation. In France, over 120,000 women have used RU-486/PG to terminate pregnancy, and this regimen is now used in about 25% of abortions. Clinical trials of RU-486 are underway in Cuba, China, India, Singapore, and Zambia. The Program for Appropriate Technology has identified four considerations for introducing RU-486 to developing countries: whether abortion or menstrual regulation is legal; whether women find the method acceptable and can comply with the multiple visit treatment regimen; whether the health infrastructure can support safe method use, including prevention of misuse and provision of appropriate medical backup personnel and facilities; and whether the cost of the regimen is affordable to individuals and/or programs --conditions unlikely to be met in most such countries. Ideal would be development of a medical abortifacient that is single dose and the lowest possible dose of each drug, provokes miscarriage within a more predictable time frame with less acute and prolonged bleeding, is safe and effective beyond two months, has minimal side effects, and maximizes short-term safety and minimizes long-term effects. Technological advances are being undermined, however, by political and religious attacks on the method. Even some feminists have expressed concerns about potential long-term effects of RU-486 use.

  5. Effect of Ru thickness on spin pumping in Ru/Py bilayer

    Energy Technology Data Exchange (ETDEWEB)

    Behera, Nilamani; Singh, M. Sanjoy; Chaudhary, Sujeet; Pandya, Dinesh K., E-mail: dkpandya@physics.iitd.ac.in; Muduli, P. K. [Department of Physics, Thin Film Laboratory, Indian Institute of Technology Delhi, New Delhi 110016 (India)

    2015-05-07

    We report the effect of Ru thickness (t{sub Ru}) on ferromagnetic resonance (FMR) line-width of Ru(t{sub Ru})/Py(23 nm) bilayer samples grown on Si(100)/SiO{sub 2} substrates at room temperature by magnetron sputtering. The FMR line-width is found to vary linearly with frequency for all thicknesses of Ru, indicating intrinsic origin of damping. For Ru thicknesses below 15 nm, Gilbert-damping parameter, α is almost constant. We ascribe this behavior to spin back flow that is operative for Ru thicknesses lower than the spin diffusion length in Ru, λ{sub sd}. For thicknesses >15 nm (>λ{sub sd}), the damping constant increases with Ru thickness, indicating spin pumping from Py into Ru.

  6. Peroxydisulfate activation by [RuII(tpy)(pic)(H2O)]+. Kinetic, mechanistic and anti-microbial activity studies.

    Science.gov (United States)

    Chatterjee, Debabrata; Banerjee, Priyabrata; Bose, Jagadeesh C K; Mukhopadhyay, Sudit

    2012-03-07

    The oxidation of [Ru(II)(tpy)(pic)H(2)O](+) (tpy = 2,2',6',2''-terpyridine; pic(-) = picolinate) by peroxidisulfate (S(2)O(8)(2-)) as precursor oxidant has been investigated kinetically by UV-VIS, IR and EPR spectroscopy. The overall oxidation of Ru(II)- to Ru(IV)-species takes place in a consecutive manner involving oxidation of [Ru(II)(tpy)(pic)H(2)O](+) to [Ru(III)(tpy)(pic)(OH)](+), and its further oxidation of to the ultimate product [Ru(IV)(tpy)(pic)(O)](+) complex. The time course of the reaction was followed as a function of [S(2)O(8)(2-)], ionic strength (I) and temperature. Kinetic data and activation parameters are interpreted in terms of an outer-sphere electron transfer mechanism. Anti-microbial activity of Ru(II)(tpy)(pic)H(2)O](+) complex by inhibiting the growth of Escherichia coli DH5α in presence of peroxydisulfate has been explored, and the results of the biological studies have been discussed in terms of the [Ru(IV)(tpy)(pic)(O)](+) mediated cleavage of chromosomal DNA of the bacteria.

  7. On-line measurements of RuO{sub 4} during a PWR severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Reymond-Laruinaz, S.; Doizi, D. [CEA, DEN, Departement de Physico-chimie, CEA/Saclay, 91191 Gif sur Yvette Cedex, (France); Manceron, L. [Societe Civile Synchrotron SOLEIL, L' Orme des Merisiers, St-Aubin BP48, 91192 Gif-sur-Yvette Cedex, (France); MONARIS, UMR 8233, Universite Pierre et Marie Curie, 4 Place Jussieu, case 49, F-75252 Paris Cedex 05, (France); Boudon, V. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, F-21078 Dijon Cedex, (France); Ducros, G. [CEA, DEN, Departement d' Etudes des Combustibles, CEA/Cadarache, 13108 Saint-Paul-lez-Durance cedex, (France)

    2015-07-01

    After the Fukushima accident, it became essential to have a way to monitor in real time the evolution of a nuclear reactor during a severe accident, in order to react efficiently and minimize the industrial, ecological and health consequences of the accident. Among gaseous fission products, the tetroxide of ruthenium RuO{sub 4} is of prime importance since it has a significant radiological impact. Ruthenium is a low volatile fission product but in case of the rupture of the vessel lower head by the molten corium, the air entering into the vessel oxidizes Ru into gaseous RuO{sub 4}, which is not trapped by the Filtered Containment Venting Systems. To monitor the presence of RuO{sub 4} allows making a diagnosis of the core degradation and quantifying the release into the atmosphere. To determine the presence of RuO{sub 4}, FTIR spectrometry was selected. To study the feasibility of the monitoring, high-resolution IR measurements were realized at the French synchrotron facility SOLEIL on the infrared beam line AILES. Thereafter, theoretical calculations were done to simulate the FTIR spectrum to describe the specific IR fingerprint of the molecule for each isotope and based on its partial pressure in the air. (authors)

  8. New insights into the nuclear structure in neutron-rich 112,114,115,116,117,118Pd

    Energy Technology Data Exchange (ETDEWEB)

    Y. X. Luo; J. O. Rasmussen; J. H. Hamilton; A. V. Ramayya; S. Frauendorf; J. K. Hwang; N. J. Stone; S. J. Zhu; N. T. Brewer; E. Wang; I. Y. Lee; S. H. Liu; G. M. TerAkopian; A. V. Daniel; Yu.Ts. Oganessian; M. A. Stoyer; R. Donangelo; W.C. Ma; J. Cole; Yue Shi; F. R. Xu

    2013-12-01

    New level schemes of 112,114,115,116,117,118Pd are established by means of ?–?–??–?–?, ?–?–?–??–?–?–? and ?–?(0)?–?(0) measurements of prompt fission y rays from 252Cf using the Gammasphere multi-detector array. Spins/parities were assigned to levels based on ?–??–? angular correlation measurements, level systematics and decay patterns. In the even-N isotopes 112,114,116Pd, two sets of odd-parity bands were identified and extended with spins measured in each band. The odd-parity bands with large level staggerings were interpreted as disturbed chirality with less pronounced triaxial deformations in the Pd isotopes than observed in the chiral symmetry breaking 110,112Ru with maximum triaxiality. Onset of wobbling motion was identified from the sign of the signature splitting in the ? band of even–even 114Pd, and probably also in 116Pd, as first seen in the N=68N=68 isotone 112Ru. Maximal triaxiality in Ru and Pd isotopes is found to be reached for N=68N=68, 112Ru and 114Pd, 4 neutrons more than predicted in the theoretical calculations. The new data and TRS calculations allowed a systematic study of the band crossings in the even-N112,114,116Pd and odd-N115,117Pd isotopes. Now we find a new overall, more complex shape evolution than previously proposed from triaxial prolate in 110Pd via triaxial oblate in 112Pd to nearly oblate in 114,116Pd with a large change of the triaxial deformation parameter y toward nearly oblate in the (pi g 9/2)2 alignment in 114,115,116,117,118Pd, and triaxial-prolate–triaxial-oblate shape coexisting bands in 115Pd.

  9. New insights into the nuclear structure in neutron-rich {sup 112,114,115,116,117,118}Pd

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y.X. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Rasmussen, J.O. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Department of Chemistry, U.C. Berkeley, Berkeley, CA 94720 (United States); Hamilton, J.H.; Ramayya, A.V. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Frauendorf, S. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Institut für Strahlenphysik, FZD-Rossendorf, D-01314 Dresden (Germany); Hwang, J.K. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Stone, N.J. [Department of Physics, Oxford University, Oxford OX1 3PU (United Kingdom); Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Zhu, S.J. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Department of Physics, Tsinghua University, Beijing 100084 (China); Brewer, N.T.; Wang, E. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Lee, I.Y. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Liu, S.H. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); UNIRIB/Oak Ridge Associated Universities, Oak Ridge, TN 37831 (United States); TerAkopian, G.M. [Joint Institute for Nuclear Research, RU-141980, Dubna (Russian Federation); Joint Institute for Heavy Ion Research, Oak Ridge, TN 37830 (United States); Daniel, A.V. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Joint Institute for Nuclear Research, RU-141980, Dubna (Russian Federation); Joint Institute for Heavy Ion Research, Oak Ridge, TN 37830 (United States); and others

    2013-12-02

    New level schemes of {sup 112,114,115,116,117,118}Pd are established by means of γ–γ–γ, γ–γ–γ–γ and γ–γ(θ) measurements of prompt fission γ rays from {sup 252}Cf using the Gammasphere multi-detector array. Spins/parities were assigned to levels based on γ–γ angular correlation measurements, level systematics and decay patterns. In the even-N isotopes {sup 112,114,116}Pd, two sets of odd-parity bands were identified and extended with spins measured in each band. The odd-parity bands with large level staggerings were interpreted as disturbed chirality with less pronounced triaxial deformations in the Pd isotopes than observed in the chiral symmetry breaking {sup 110,112}Ru with maximum triaxiality. Onset of wobbling motion was identified from the sign of the signature splitting in the γ band of even–even {sup 114}Pd, and probably also in {sup 116}Pd, as first seen in the N=68 isotone {sup 112}Ru. Maximal triaxiality in Ru and Pd isotopes is found to be reached for N=68, {sup 112}Ru and {sup 114}Pd, 4 neutrons more than predicted in the theoretical calculations. The new data and TRS calculations allowed a systematic study of the band crossings in the even-N{sup 112,114,116}Pd and odd-N{sup 115,117}Pd isotopes. Now we find a new overall, more complex shape evolution than previously proposed from triaxial prolate in {sup 110}Pd via triaxial oblate in {sup 112}Pd to nearly oblate in {sup 114,116}Pd with a large change of the triaxial deformation parameter γ toward nearly oblate in the (πg{sub 9/2}){sup 2} alignment in {sup 114,115,116,117,118}Pd, and triaxial-prolate–triaxial-oblate shape coexisting bands in {sup 115}Pd.

  10. Dermatologic complications of anti-PD-1/PD-L1 immune checkpoint antibodies.

    Science.gov (United States)

    Sibaud, Vincent; Meyer, Nicolas; Lamant, Laurence; Vigarios, Emmanuelle; Mazieres, Julien; Delord, Jean Pierre

    2016-07-01

    The therapeutic use of anti-PD-1/PD-L1 antibodies (nivolumab, pembrolizumab) is rapidly increasing. Given their mechanism of action that triggers T-cell activation, these immune checkpoint inhibitors induce specific adverse events that are mostly of immunologic origin. In this way, cutaneous toxicities represent the most frequent immune-related adverse events (irAEs). The purpose of this review is to summarize the most prevalent dermatologic complications induced by PD-1/PD-L1 immune checkpoint-blocking antibodies and to compare their dermatologic safety profile with anti-CTLA-4 ipilimumab. More than 40% of melanoma patients treated with anti-PD-1 therapy are faced with dermatologic irAEs. However, these cutaneous complications usually remain self-limiting and readily manageable. Nonspecific macular papular rash and pruritus represent the most common manifestations. More characteristic lichenoid dermatitis or psoriasis may also develop. Vitiligo is also frequent in patients with melanoma but has not been reported in other types of solid cancers. Mucosal involvement may also occur, including xerostomia and lichenoid reactions. Although available data remain scarce, anti-PD-L1 antibodies present a similar dermatologic safety profile. Dermatologic irAEs induced by PD-1 or PD-L1 blockade therapy rarely result in significant morbidity or permanent discontinuation of treatment. However, early recognition and appropriate management are crucial for restricting dose-limiting toxicities.

  11. All-trans-[ClRu(II)(py)4(NC)Ru(II)(py)4(CN)Ru(II)(py)4(NO)](PF6)4: a redox-active 2-donor/1-acceptor system based on the electrophilic {RuNO}6 motif.

    Science.gov (United States)

    De Candia, Ariel G; Singh, Priti; Kaim, Wolfgang; Slep, Leonardo D

    2009-01-19

    The new linear homotrinuclear compound trans-[ClRu(II)(py)(4)(NC)Ru(II)(py)(4)(CN)Ru(II)(py)(4)(NO)](PF(6))(4) was prepared by reaction between the nitro complex trans-[(NC)Ru(II)(py)(4)(CN)Ru(II)(py)(4)(NO(2))](+) and the solvento complex obtained by reaction between [ClRu(II)(py)(4)(NO)](3+) and N(3)(-) in acetone. The trans-[ClRu(II)(py)(4) (NC)Ru(II)(py)(4)(CN)Ru(II)(py)(4)(NO)](4+) ion (I) has been characterized by (1)H NMR and IR spectroscopy (nu(NO) = 1919 cm(-1)). This species displays intense electronic absorptions in the visible region which can be assigned to donor-acceptor charge-transfer transitions (DACT) involving {RuNO}(6)-centered acceptor orbitals and donor orbitals located on the two different neighboring metal centers at ca. 6.7 and 12.6 A distance from the metal in the {RuNO}(6) fragment. Addition of OH(-) to I generated the nitro complex with a second-order rate constant of (12.5 +/- 0.2) x 10(3) M(-1) s(-1) (25 degrees C). Cyclic voltammetry experiments complemented by spectroelectrochemistry in the UV-vis-NIR region reveal that I can be reversibly reduced at 0.49 or 0.20 V vs AgCl/Ag for acetonitrile and water, respectively, and oxidized at 0.71 or 0.57 V vs AgCl/Ag. The spectroscopic and spectroelectrochemical information (UV-vis-NIR, X-band EPR) supplemented with electronic structure computation (DFT) reveals that the one-electron reduction is centered on the nitrosyl moiety to yield a {RuNO}(7) species, while oxidation occurs on the chlororuthenium side of the molecule. Both processes yield significant changes of the electronic spectra which are discussed in parallel with the electronic structure picture as obtained by DFT.

  12. The series of carbon-chain complexes {Ru(dppe)Cp*}₂{μ-(C≡C)x} (x = 4–8, 11): Synthesis, structures, properties and some reactions

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, Michael I. [Univ. of Adelaide, South Australia (Australia); Cole, Marcus L. [Univ. of Adelaide, South Australia (Australia); Ellis, Benjamin G. [Univ. of Adelaide, South Australia (Australia); Gaudio, Maryka [Univ. of Adelaide, South Australia (Australia); Nicholson, Brian K. [Univ. of Waikato, Hamilton (New Zealand); Parker, Christian R. [Univ. of Adelaide, South Australia (Australia); Skelton, Brian W. [Univ. of Western Australia, Crawley (Western Australia); White, Allan H. [Univ. of Western Australia, Crawley (Western Australia)

    2015-01-28

    The construction of a series of compounds {Ru(dppe)Cp*}2(μ-C2x) (Ru*-C2x-Ru*, x = 4–8, 11)) is described. A direct reaction between RuCl(dppe)Cp* and Me3Si(Ctriple bond; length of mdashC)4SiMe3 afforded Ru*-C8-Ru* in 89% yield. The Pd(0)/Cu(I)-catalysed coupling of Ru{Ctriple bond; length of mdashCCtriple bond; length of mdashCAu(PPh3)}(dppe)Cp*Ru*-C4-Au (2 equiv.) with diiodoethyne gave Ru*-C10-Ru* (64%), or of 1 equiv. with I(Ctriple bond; length of mdashC)3I gave Ru*-C14-Ru* (36%); similarly, Ru{(Ctriple bond; length of mdashC)4Au(PPh3)}(dppe)Cp*Ru*-C8-Au and I(Ctriple bond; length of mdashC)3I gave Ru*-C22-Ru* (12%). Desilylation (TBAF) of Ru{(Ctriple bond; length of mdashC)xSiMe3}(dppe)Cp*Ru*-C2x-Si (x = 3, 4) followed by oxidative coupling [Cu(OAc)2/py] gave Ru*-C12-Ru* (82%) and Ru*-C16-Ru* (58%), respectively. Similar oxidative coupling of Ru(Ctriple bond; length of mdashCCtriple bond; length of mdashCH)(dppe)Cp* was a second route to Ru*-C8-Ru* (82%). Appropriate precursors are already known, or obtained by coupling of Ru*-C2x-Si (x = 2, 4) with AuCl(PPh3)/NaOMe [Ru*-C4-Au, 95%; Ru*-C8-Au, 74%] or from Pd(0)/Cu(I) catalysed coupling of Ru*-C2x-Au (x = 2, 3) with I(Ctriple bond; length of mdashC)2SiMe3 (Ru*-C8-Si, 64%; Ru*-C10-Si, 2%). Reactions between Ru*-C2x-Ru* (x = 3, 4) and Fe2(CO)9 gave {Fe3(CO)9}{μ3-CCtriple bond; length of mdashC[Ru(dppe)Cp*]}2Fe(C3-Ru*)2 and {Fe3(CO)9}{μ3-CCtriple bond; length of mdashC[Ru(dppe)Cp*]}{μ3-C(Ctriple bond; length of mdashC)2[Ru(dppe)Cp*]} Fe(C3-Ru*)(C5-Ru*), respectively. The redox properties of the series of complexes with 2x = 2–16 were measured and showed a diminution of the

  13. PD Lab

    OpenAIRE

    Bilow, Marcel; Entrop, Bram; Lichtenberg, Jos; Stoutjesdijk, Pieter

    2015-01-01

    PD Lab explores the applications of building sector related product development. PD lab investigates and tests digital production technologies like CNC milled wood connections. It will also act as a platform in its wider meaning to investigate the effects and influences of file to factory production, to explore the potential in the field of sustainability, material use, logistics and the interaction of stakeholders within the chain of the building process.

  14. Synthesis and Electronic Structure of Ru2(Xap)4(Y-gem-DEE) Type Compounds: Effect of Cross-Conjugation.

    Science.gov (United States)

    Forrest, William P; Choudhuri, Mohommad M R; Kilyanek, Stefan M; Natoli, Sean N; Prentice, Boone M; Fanwick, Phillip E; Crutchley, Robert J; Ren, Tong

    2015-08-03

    Reported in this Article are the preparation and characterization of a series of new Ru2(II,III) compounds bearing one cross-conjugated σ-geminal-diethynylethene ligand (gem-DEE), namely, Ru2(Xap)4(Y-gem-DEE) (Xap = N,N'-anilinopyridinate (ap) or 2-(3,5-dimethoxy)anilinopyridinate (DiMeOap), and Y = Si(i)Pr3 (1) or H (2)) and [Ru2(ap)4]2(μ-gem-DEE) (3). Compounds 1-3 were characterized by spectroscopic and voltammetric techniques as well as the single crystal X-ray diffraction study of 2a. The X-ray structural data of 2a and the spectroscopic/voltammetric data of compounds 1 and 2 indicate that the gem-DEE ligands are similar to simple alkynyls in their effects on the molecular and electronic structures of the Ru2(Xap)4 moiety. Similar to the previously studied [Ru2(ap)4]2(μ-C2n) type compounds, dimer 3 exhibits pairwise 1e(-) oxidations and reductions, albeit the potential splits within the pair (ΔE1/2) are significantly smaller than those of [Ru2(ap)4]2(μ-C4). The electronic absorption spectra of the reduced and oxidized derivatives of 1a and 3 were determined using spectroelectrochemistry methods. No discernible intervalence charge transfer transition (IVCT) was detected in the near-IR spectrum for either 3(-) or 3(+), suggesting that the Ru2-Ru2 coupling in these mixed-valence states is weak. DFT calculations on a model compound of 3 yielded six singly occupied molecular orbitals (SOMOs), which have Ru2 contributions similar to those previously calculated for the [Ru2(ap)4]2(μ-C2n) type compounds. Among six SOMOs, SOMO-2 is the only one containing substantial dπ-π(gem-DEE) character across the entire Ru2-μ-gem-DEE-Ru2 linkage, which explains the weakened Ru2-Ru2 coupling.

  15. Self-assembly of Ru4 and Ru8 assemblies by coordination using organometallic Ru(II2 precursors: Synthesis, characterization and properties

    Directory of Open Access Journals (Sweden)

    Sankarasekaran Shanmugaraju

    2012-02-01

    Full Text Available Coordination-driven self-assembly of binuclear half-sandwich p-cymene ruthenium(II complexes [Ru2(μ-η4-C2O4(MeOH2(η6-p-cymene2](O3SCF32 (1a or [Ru2(μ-η4-N,N'-diphenyloxamidato(MeOH2(η6-p-cymene2](O3SCF32 (1b separately with an imidazole-based tetratopic donor L in methanol affords two tetranuclear metallamacrocycles 2a and 2b, respectively. Conversely, the similar combination of L with 2,5-dihydroxy-1,4-benzoquinonato (dhbq bridged binuclear complex [Ru2(μ-η4-C6H2O4(MeOH2(η6-p-cymene2](O3SCF32 (1c in 1:2 molar ratio resulted in an octanuclear macrocyclic cage 2c. All the self-assembled macrocycles 2a–2c were isolated as their triflate salts in high yields and were characterized fully by multinuclear (1H, 13C and 19F NMR, infrared (IR and electrospray ionization mass spectrometry (ESIMS. In addition, the molecular structure of macrocycle 2a was established unequivocally by single-crystal X-ray diffraction analysis and adopts a tetranuclear rectangular geometry with the dimensions of 5.53 Å × 12.39 Å. Furthermore, the photo- and electrochemical properties of these newly synthesized assemblies have been studied by using UV–vis absorption and cyclic voltammetry analysis.

  16. Synthesis, Characterization, Anticancer, and Antioxidant Studies of Ru(III) Complexes of Monobasic Tridentate Schiff Bases

    Science.gov (United States)

    Ejidike, Ikechukwu P.

    2016-01-01

    Mononuclear Ru(III) complexes of the type [Ru(LL)Cl2(H2O)] (LL = monobasic tridentate Schiff base anion: (1Z)-N′-(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)-N-phenylethanimidamide [DAE], 4-[(1E)-N-{2-[(Z)-(4-hydroxy-3-methoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol [HME], 4-[(1E)-N-{2-[(Z)-(3,4-dimethoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol [MBE], and N-(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)benzenecarboximidoyl chloride [DEE]) were synthesized and characterized using the microanalytical, conductivity measurements, electronic spectra, and FTIR spectroscopy. IR spectral studies confirmed that the ligands act as tridentate chelate coordinating the metal ion through the azomethine nitrogen and phenolic oxygen atom. An octahedral geometry has been proposed for all Ru(III)-Schiff base complexes. In vitro anticancer studies of the synthesized complexes against renal cancer cells (TK-10), melanoma cancer cells (UACC-62), and breast cancer cells (MCF-7) was investigated using the Sulforhodamine B assay. [Ru(DAE)Cl2(H2O)] showed the highest activity with IC50 valves of 3.57 ± 1.09, 6.44 ± 0.38, and 9.06 ± 1.18 μM against MCF-7, UACC-62, and TK-10, respectively, order of activity being TK-10 [Ru(HME)Cl2(H2O)] > [Ru(DAE)Cl2(H2O)] > [Ru(MBE)Cl2(H2O)]. PMID:27597814

  17. EXAFS Peaks and TPR Characterizing Bimetallic Interactions: Effects of Impregnation Methods on the Structure of Pt-Ru/C Catalysts

    Directory of Open Access Journals (Sweden)

    Nan-Yu Chen

    2014-01-01

    Full Text Available To investigate bimetallic interactions, Pt-Ru/C catalysts were prepared by coimpregnation (Pt-Ruco/C and successive impregnation (Ru-Ptse/C, while Pt/C, Ru/C, and reduced Pt-Rublack were used as reference. Those samples were characterized by XAS and TPR. When Pt(absorber-Ru(backscatter phase-and-amplitude correction is applied to Fourier transformed (FT EXAFS of Pt-Rublack at Pt edge, the characteristic peak of Pt-Ru interactions appears at 2.70 Å´, whereas, when Pt-Pt correction is applied, the peak appears at about 2.5 Å´. Detailed EXAFS analysis for Pt-Ruco/C and Pt-Ruse/C confirms the nature of the characteristic peak and further indicates that the interactions can semiquantitatively be determined by the relative intensity between Pt-Ru and Pt-Pt characteristic peaks. This simple method in determining bimetallic interaction can be extended to characterize Pt-Pd/γ-Al2O3. However, for Pt-Re/γ-Al2O3, Pt-Re interactions cannot be determined by the method because of the overlap of Pt-Pt and Pt-Re characteristic peaks due to similar phase functions.

  18. DNA-binding, cytotoxicity, cellular uptake, apoptosis and photocleavage studies of Ru(II) complexes.

    Science.gov (United States)

    N Deepika; C Shobha Devi; Y Praveen Kumar; K Laxma Reddy; P Venkat Reddy; D Anil Kumar; Surya S Singh; S Satyanarayana

    2016-07-01

    Two Ru(II) complexes [Ru(phen)2bppp](ClO4)2 (1) and [Ru(phen)27-Br-dppz](ClO4)2 (2) [phen=1,10 phenanthroline, 7-Br-dppz=7-fluorodipyrido[3,2-a:2',3'-c]phenazine, bppp=11-bromo-pyrido[2',3':5,6]pyrazino[2,3-f] [1,10]phenanthroline] have been synthesized and characterized by elemental analysis, ES-MS, (1)H-NMR, (13)C-NMR and IR. The in vitro cytotoxicity of the complexes examined against a panel of cancer cell lines (HeLa, Du145 and A549) by MTT method, both complexes show prominent anticancer activity against various cancer cells. Live cell imaging study and flow cytometric analysis demonstrate that both the complexes 1 and 2 could cross the cell membrane accumulating in the nucleus. Further, flow cytometry experiments showed that the cytotoxic Ru(II) complexes 1 and 2 induced apoptosis of HeLa tumor cell lines. Photo induced DNA cleavage studies have been performed and results indicate that both the complexes efficiently photo cleave pBR322 DNA. The binding properties of two complexes toward CT-DNA were investigated by various optical methods and viscosity measurements. The experimental results suggested that both Ru(II) complexes can intercalate into DNA base pairs. The complexes were docked into DNA-base pairs using the GOLD docking program.

  19. Substituted tertiary phosphine Ru(II) organometallics: catalytic utility on the hydrolysis of etofibrate in pharmaceuticals.

    Science.gov (United States)

    Reddy, P Muralidhar; Shanker, Kanne; Rohini, Rondla; Sarangapani, M; Ravinder, Vadde

    2008-10-01

    Some new organometallics of ruthenium(II) of the type [RuCl2(COD)(CO)L] (1a-f) and [RuCl2(COD)L2] (2a-f) (where L is substituted tertiary phosphines), have been synthesized by using precursors [RuCl2(COD)(CO)(CH3CN)] (1) and [RuCl2(COD)(CH3CN)2] (2) with the substituted tertiary phosphine ligands in 1:1 and 1:2 molar ratio. The organometallics (2a-f) have been further reacted with carbonmonoxide to produce compounds of the type [RuCl2(CO)L2] (3a-f). These compounds were characterized by elemental analysis, IR, NMR (1H, 13C and 31P), mass and electronic spectral data. The catalytic activity of all these organometallics were studied and found that they are efficient catalysts for hydrolysis of etofibrate. The hydrolyzed product was separated by column chromatography and the percent yields are found in the range of 98.6-99.1%.

  20. Ru-Sn/AC for the Aqueous-Phase Reduction of Succinic Acid to 1,4-Butanediol under Continuous Process Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Settle, Amy E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vorotnikov, Vassili [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Menart, Martin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eaton, Todd R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Steirer, Kenneth X [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wood, Kevin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cleveland, Nicholas S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Moyer, Kathleen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Michener, William E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Unocic, Kinga A. [Oak Ridge National Laboratory

    2017-08-01

    Succinic acid is a biomass-derived platform chemical that can be catalytically converted in the aqueous phase to 1,4-butanediol (BDO), a prevalent building block used in the polymer and chemical industries. Despite significant interest, limited work has been reported regarding sustained catalyst performance and stability under continuous aqueous-phase process conditions. As such, this work examines Ru-Sn on activated carbon (AC) for the aqueous-phase conversion of succinic acid to BDO under batch and flow reactor conditions. Initially, powder Ru-Sn catalysts were screened to determine the most effective bimetallic ratio and provide a comparison to other monometallic (Pd, Pt, Ru) and bimetallic (Pt-Sn, Pd-Re) catalysts. Batch reactor tests determined that a ~1:1 metal weight ratio of Ru to Sn was effective for producing BDO in high yields, with complete conversion resulting in 82% molar yield. Characterization of the fresh Ru-Sn catalyst suggests that the sequential loading method results in Ru sites that are colocated and surface-enriched with Sn. Postbatch reaction characterization confirmed stable Ru-Sn material properties; however, upon a transition to continuous conditions, significant Ru-Sn/AC deactivation occurred due to stainless steel leaching of Ni that resulted in Ru-Sn metal crystallite restructuring to form discrete Ni-Sn sites. Computational modeling confirmed favorable energetics for Ru-Sn segregation and Ni-Sn formation at submonolayer Sn incorporation. To address stainless steel leaching, reactor walls were treated with an inert silica coating by chemical vapor deposition. With leaching reduced, stable Ru-Sn/AC performance was observed that resulted in a molar yield of 71% BDO and 15% tetrahydrofuran for 96 h of time on stream. Postreaction catalyst characterization confirmed low levels of Ni and Cr deposition, although early-stage islanding of Ni-Sn will likely be problematic for industrially relevant time scales (i.e., thousands of hours). Overall

  1. Formation of graphene on Ru(0001) surface

    Institute of Scientific and Technical Information of China (English)

    Pan Yi; Shi Dong-Xia; Gao Hong-Jun

    2007-01-01

    We report on the formation of a graphene monolayer on a Ru(0001) surface by annealing the Ru(0001) crystal.The samples are characterized by scanning tunnelling microscopy (STM) and Auger electron spectroscopy (AES). STM images show that the Moiré pattern is caused by the graphene layer mismatched with the underlying Ru(0001) surface and has an N × N superlattice. It is further found that the graphene monolayer on a Ru(0001) surface is very stable at high temperatures. Our results provide a simple and convenient method to produce a graphene monolayer on the Ru(0001) surface, which is used as a template for fabricating functional nanostructures needed in future nano devices and catalysis.

  2. CoTaZr/Pd multilayer with perpendicular magnetic anisotropy

    Directory of Open Access Journals (Sweden)

    Yong Chang Lau

    2013-08-01

    Full Text Available We report a novel perpendicularly magnetized thin film [Co91.5Ta4.5Zr4/Pd]5 multilayer, which exhibits strong perpendicular magnetic anisotropy when grown on 5 nm of Pd and Ru seed layers. The Pd-seeded multilayer annealed at 300 °C shows an effective uniaxial anisotropy constant, Keff = 1.1 MJ m−3, with an anisotropy field as high as 1.6 T. The perpendicular anisotropy is sustained on annealing at 400 °C for 1 h. X-ray diffraction on multilayers with 30 repeats suggests that the use of amorphous CoTaZr reduces the stress of the stack, compared to [Co/Pd] multilayer.

  3. First-principles study on magnetism of Ru monolayer under an external electric field

    Science.gov (United States)

    Kitaoka, Yukie; Imamura, Hiroshi

    Electric field control of magnetic properties such as magnetic moment and magnetic anisotropy has been attracted. For the 4 d TM films, on the other hand, it was recently reported that the ferromagnetism Pd thin-film is induced by application of an external electric field otherwise Pd thin-film shows paramagnetic. However, little attention has been paid to the magnetism of other 4 d TMs. Here, we investigate the magnetism of the free-standing Ru monolayer and that on MgO(001) substrate under an external electric field by using first-principles FLAPW method. We found that the free-standing Ru monolayer is ferromagnet with magnetic moment of 1.50 ¥muB /atom. The MA energy is 3.45 meV/atom, indicating perpendicular MA, at zero electric field (E=0) and increases up to 3.84 meV/atom by application of E=1 (V/¥AA). The Ru monolayer on MgO(001) substrate is also ferromagnet with magnetic moment of 0.89 ¥muB /atom. The MA energy is 1.49 meV/atom, indicating perpendicular MA, at E=0 and decreases to 1.33 meV/atom by application of E=1 (V/¥AA).

  4. Ru(III)-catalyzed oxidation of pyridoxine and albuterol in pharmaceuticals

    Science.gov (United States)

    Ashok, More; Prasad, Adapa V. S. S.; Reddy, P. Muralidhar; Ravinder, Vadde

    2009-02-01

    Ru(III) complexes with coordinated amide were synthesized and characterized by elemental, IR, mass, electronic, ESR spectral analysis, magnetic and conductance measurements and octahedral structures have been proposed. These complexes were used as catalysts for the oxidation of pyridoxine and albuterol in pharmaceuticals in presence of hydrogen peroxide. The role of co-oxidant and the effect of reaction time on the yields of oxidation products which were spectrophotometrically determined by condensing them with sulfanilic acid in acid medium were investigated. Structures of the oxidation products were established with the help of IR and NMR spectral analysis.

  5. Scanning tunnelling microscope studies of growth of RuO2(110) thin layer on Ru(0001)

    Institute of Scientific and Technical Information of China (English)

    Zhang Han-Jie; Lü Bin; Lu Yun-Hao; Huang Han; Li Hai-Yang; Bao Shi-Ning; He Pei-Mo

    2006-01-01

    This paper reports that the growth of RuO2(110) thin layer growth on Ru(0001) has been investigated by means of scanning tunnelling microscope (STM). The STM images showed a domain structure with three rotational domains of RuO2(110) rotated by an angle of 120°. The as-grown RuO2(110) thin layer is expanded from the bulk-truncated RuCO2(110) due to the large mismatch between RuCO2(110) and the Ru(0001) substrate. The results also indicate that growth of RuO2(110) thin layer on the Ru(0001) substrate by oxidation tends first to formation of the Ru-O (oxygen) chains in the [001] direction of RuO2(110).

  6. 焙烧气氛对Ba-Ru/MgO催化剂氨合成性能的影响%Effect of calcination atmosphere on the performance of Ba-Ru/MgO catalysts for ammonia synthesis

    Institute of Scientific and Technical Information of China (English)

    杨晓龙; 唐立平; 熊绪茂; 慕新元; 胡斌

    2012-01-01

    采用浸渍法制备Ba-Ru/MgO系列催化剂,考察不同焙烧气氛对Ba-Ru/MgO催化剂氨合成性能的影响,通过X射线衍射、N2-低温物理吸附、透射电镜、H2程序升温还原、CO2程序升温脱附和红外光谱等方法对其进行表征,考察焙烧气氛对负载型钌基氨合成催化剂的物相结构、织构性能、微观形貌、钌物种的还原性能和体系酸碱性能等影响.研究表明,MsO焙烧气氛对制备的钌基氨合成催化剂结构、物化性能以及氨合成活性有较大影响,不同气氛焙烧对Ba-Ru/MgO催化剂碱性强弱影响顺序:Ba-Ru/MgO(Ar)>Ba-Ru/MgO(N2)>Ba-Ru/MgO(空气)>Ba-Ru/MgO(真空),在450℃、5.0MPa和5000h-1条件下,空气、Ar和N2气氛焙烧的MgO制备的Ba-Ru/MgO催化剂活性高于真空气氛焙烧的MgO制备的催化剂.%Ba-Ru/MgO catalysts were prepared by impregnation method. The effects of calcination atmos phere on the properties of Ba-Ru/MgO catalysts for ammonia synthesis were investigated. The phase struc ture , texture structure performance, the morphology, reduction properties of ruthenium species, surface acidity and basicity of the catalysts were characterized by means of XRD,N2 adsorption-desorption,TEM, H2-TPR,CO2-TPD and FT-IR. The results indicated that the calcination atmosphere for MgO support had great influence on the structure, physicochemical properties and ammonia synthesis activity of Ba-Ru/MgO catalysts. The basicity of Ba-Ru/MgO catalyst decreased in sequence as follows; Ba-Ru/MgO ( Ar) > Ba-Ru/MgO(N2) >Ba-Ru/MgO(Air) > Ba-Ru/MgO( vacuum). Under the condition of 450 ℃,5.0 Mpa and 5 000 h-1 ,the ammonia synthesis activity of Ba-Ru/MgO catalysts with MgO supports prepared under the calcination atmosphere of air, Ar and N2 was higher than that of Ba-Ru/MgO with MgO support prepared under the calcination atmosphere of vacuum.

  7. Experimental observation and computational study of the spin-gap excitation in Ba3BiRu2O9

    Science.gov (United States)

    Ling, C. D.; Huang, Z.; Kennedy, B. J.; Rols, S.; Johnson, M. R.; Zbiri, M.; Kimber, S. A. J.; Hudspeth, J.; Adroja, D. T.; Rule, K. C.; Avdeev, M.; Blanchard, P. E. R.

    2016-11-01

    Ba3BiRu2O9 is a 6H-type perovskite compound containing face-sharing octahedral M2O9 (M =Ir , Ru) dimers, which are magnetically frustrated at low temperatures. On cooling through T*=176 K, it undergoes a pronounced magnetostructural transition, which is not accompanied by any change in space group symmetry, long-range magnetic ordering, or charge ordering. Here, we report the first direct evidence from inelastic neutron scattering that this transition is due to an opening of a gap in the excitation spectra of dimers of low-spin Ru4 + (S =1 ) ions. X-ray absorption spectroscopy reveals a change in Ru-Ru orbital overlap at T*, linking the emergence of this spin-gap excitation to the magnetostructural transition. Ab initio calculations point to a geometrically frustrated magnetic ground state due to antiferromagnetic interdimer exchange on a triangular Ru2O9 dimer lattice. X-ray total-scattering data rule out long-range magnetic ordering at low temperatures, consistent with this geometrically frustrated model.

  8. Thermodynamic assessment of the Al-Ru system

    CSIR Research Space (South Africa)

    Prins, SN

    2003-03-01

    Full Text Available describes the order disorder transformation with one Gibbs energy function. The RuAl6 phase was described as a stoichiometric phase and the remaining intermetallic phases (Ru4Al13, RuAl2 and Ru2Al3) were modelled with the sublattice model. The solubility...

  9. Highly Active and Stable MgAl2O4 Supported Rh and Ir Catalysts for Methane Steam Reforming: A Combined Experimental and Theoretical Study

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Donghai; Glezakou, Vassiliki Alexandra; Lebarbier, Vanessa MC; Kovarik, Libor; Wan, Haiying; Albrecht, Karl O.; Gerber, Mark A.; Rousseau, Roger J.; Dagle, Robert A.

    2014-07-01

    In this work we present a combined experimental and theoretical investigation of stable MgAl2O4 spinel-supported Rh and Ir catalysts for the steam methane reforming (SMR) reaction. Firstly, catalytic performance for a series of noble metal catalysts supported on MgAl2O4 spinel was evaluated for SMR at 600-850°C. Turnover rate at 850°C follows the order: Pd > Pt > Ir > Rh > Ru > Ni. However, Rh and Ir were found to have the best combination of activity and stability for methane steam reforming in the presence of simulated biomass-derived syngas. It was found that highly dispersed ~2 nm Rh and ~1 nm Ir clusters were formed on the MgAl2O4 spinel support. Scanning Transition Electron Microscopy (STEM) images show that excellent dispersion was maintained even under challenging high temperature conditions (e.g. at 850°C in the presence of steam) while Ir and Rh catalysts supported on Al2O3 were observed to sinter at increased rates under the same conditions. These observations were further confirmed by ab initio molecular dynamics (AIMD) simulations which find that ~1 nm Rh and Ir particles (50-atom cluster) bind strongly to the MgAl2O4 surfaces via a redox process leading to a strong metal-support interaction, thus helping anchor the metal clusters and reduce the tendency to sinter. Density functional theory (DFT) calculations suggest that these supported smaller Rh and Ir particles have a lower work function than larger more bulk-like ones, which enables them to activate both water and methane more effectively than larger particles, yet have a minimal influence on the relative stability of coke precursors. In addition, theoretical mechanistic studies were used to probe the relationship between structure and reactivity. Consistent with the experimental observations, our theoretical modeling results also suggest that the small spinel-supported Ir particle catalyst is more active than the counterpart of Rh catalyst for SMR. This work was financially supported by the

  10. Selective oxidation of methylamine over zirconia supported Pt-Ru, Pt and Ru catalysts

    Institute of Scientific and Technical Information of China (English)

    Aiying Song; Gongxuan Lu

    2015-01-01

    Pt–Ru, Pt and Ru catalysts supported on zirconia were prepared by impregnation method and were tested in se-lective oxidation of methylamine (MA) in aqueous media. Among three catalysts, Ru/ZrO2 was more active than Pt/ZrO2 while Pt–Ru/ZrO2 demonstrated the best catalytic activity due to the fact that Pt addition efficiently pro-moted the dispersion of active species in bimetallic catalyst. Therefore, the~100%TOC conversion and N2 selec-tivity were achieved over Pt–Ru/ZrO2, Pt/ZrO2 and Ru/ZrO2 catalysts at 190, 220 and 250 °C, respectively.

  11. Nanoscale decomposition of Nb-Ru-O

    Science.gov (United States)

    Music, Denis; Geyer, Richard W.; Chen, Yen-Ting

    2016-11-01

    A correlative theoretical and experimental methodology has been employed to explore the decomposition of amorphous Nb-Ru-O at elevated temperatures. Density functional theory based molecular dynamics simulations reveal that amorphous Nb-Ru-O is structurally modified within 10 ps at 800 K giving rise to an increase in the planar metal - oxygen and metal - metal population and hence formation of large clusters, which signifies atomic segregation. The driving force for this atomic segregation process is 0.5 eV/atom. This is validated by diffraction experiments and transmission electron microscopy of sputter-synthesized Nb-Ru-O thin films. Room temperature samples are amorphous, while at 800 K nanoscale rutile RuO2 grains, self-organized in an amorphous Nb-O matrix, are observed, which is consistent with our theoretical predictions. This amorphous/crystalline interplay may be of importance for next generation of thermoelectric devices.

  12. PHARMACOKINETICS OF RU486 IN RABBITS

    Institute of Scientific and Technical Information of China (English)

    ZHANGMing-Hua; CHUYun-Hong; LIQui; CHANGLi-Min; FANGZhen; JINGZuao-Ying

    1989-01-01

    Intravaginal release of contraceptive steroid by avoiding the first-pass effect may provide a suitable route of administration, thus leading to higher bioavailabilities. RU486 is significantly metabolizlcd by the first-pass metabolism. We have studied its pharmacokinetics

  13. Support Screening Studies on the Hydrogenation of Levulinic Acid to γ-Valerolactone in Water Using Ru Catalysts

    Directory of Open Access Journals (Sweden)

    Anna Piskun

    2016-08-01

    Full Text Available γ-Valerolactone (GVL has been identified as a sustainable platform chemical for the production of carbon-based chemicals. Here we report a screening study on the hydrogenation of levulinic acid (LA to GVL in water using a wide range of ruthenium supported catalysts in a batch set-up (1 wt. % Ru, 90 °C, 45 bar of H2, 2 wt. % catalyst on LA. Eight monometallic catalysts were tested on carbon based(C, carbon nanotubes (CNT and inorganic supports (Al2O3, SiO2, TiO2, ZrO2, Nb2O5 and Beta-12.5. The best result was found for Ru/Beta-12.5 with almost quantitative LA conversion (94% and 66% of GVL yield after 2 h reaction. The remaining product was 4-hydroxypentanoic acid (4-HPA. Catalytic activity for a bimetallic RuPd/TiO2 catalyst was by far lower than for the monometallic Ru catalyst (9% conversion after 2 h. The effects of relevant catalyst properties (average Ru nanoparticle size, Brunauer-Emmett-Teller (BET surface area, micropore area and total acidity on catalyst activity were assessed.

  14. A highly active and stable IrOx/SrIrO3 catalyst for the oxygen evolution reaction.

    Science.gov (United States)

    Seitz, Linsey C; Dickens, Colin F; Nishio, Kazunori; Hikita, Yasuyuki; Montoya, Joseph; Doyle, Andrew; Kirk, Charlotte; Vojvodic, Aleksandra; Hwang, Harold Y; Norskov, Jens K; Jaramillo, Thomas F

    2016-09-02

    Oxygen electrochemistry plays a key role in renewable energy technologies such as fuel cells and electrolyzers, but the slow kinetics of the oxygen evolution reaction (OER) limit the performance and commercialization of such devices. Here we report an iridium oxide/strontium iridium oxide (IrOx/SrIrO3) catalyst formed during electrochemical testing by strontium leaching from surface layers of thin films of SrIrO3 This catalyst has demonstrated specific activity at 10 milliamps per square centimeter of oxide catalyst (OER current normalized to catalyst surface area), with only 270 to 290 millivolts of overpotential for 30 hours of continuous testing in acidic electrolyte. Density functional theory calculations suggest the formation of highly active surface layers during strontium leaching with IrO3 or anatase IrO2 motifs. The IrOx/SrIrO3 catalyst outperforms known IrOx and ruthenium oxide (RuOx) systems, the only other OER catalysts that have reasonable activity in acidic electrolyte.

  15. Understanding Pd-Pd bond length variation in (PNP)Pd-Pd(PNP) dimers.

    Science.gov (United States)

    Walensky, Justin R; Fafard, Claudia M; Guo, Chengyun; Brammell, Christina M; Foxman, Bruce M; Hall, Michael B; Ozerov, Oleg V

    2013-03-04

    Analysis of the structures of three (PNP)Pd-Pd(PNP) dimers [where PNP stands for anionic diarylamido/bis(phosphine) pincer ligands] has been carried out with the help of single-crystal X-ray diffractometry and density functional theory (DFT) calculations on isolated molecules. The three dimers under study possess analogous ancillary ligands; two of them differ only by an F versus Me substituent in a remote (five bonds away from Pd) position of the pincer ligand. Despite these close similarities, X-ray structural determinations revealed two distinct structural motifs: a highly symmetric molecule with a long Pd-Pd bond or a highly distorted molecule with Pd-Pd bonds ca. 0.14 Å shorter. DFT calculations on a series of (PNP)Pd-Pd(PNP) dimers (as molecules in the gas phase) confirmed the existence of these distinct minima for dimers carrying large isopropyl substituents on the P-donor atoms (as in the experimental structure). These minima are nearly isoergic conformers. Evidently, the electronically preferred symmetric structure for the dimer (with a square-planar environment about Pd and a linear N-Pd-Pd-N vector) is not sterically possible with the preferred Pd-Pd distance. Thus, the minima correspond to either a symmetric structure with a long Pd-Pd bond distance or a structure with a short Pd-Pd distance but with substantial distortions in the Pd coordination environment to alleviate steric conflict. This notion is supported by finding only a single minimum (symmetric and with short Pd-Pd bonds) for each of the dimers carrying smaller substituents (H or Me) on the P atoms, regardless of the remote substitution.

  16. Mononuclear Ru(III) Schiff base complexes: Synthesis, spectral, redox, catalytic and biological activity studies

    Science.gov (United States)

    Priya, N. Padma; Arunachalam, S.; Manimaran, A.; Muthupriya, D.; Jayabalakrishnan, C.

    2009-04-01

    An octahedral ruthenium(III) Schiff base complexes of the type [RuX(EPh 3)(L)] (where, X = Cl/Br; E = As/P; L = dianion of the Schiff bases derived from acetoacetanilide with o-phenylenediamine and salicylaldehyde/ o-hydroxyacetophenone/ o-vanillin/2-hydroxy-1-naphthaldehyde) have been synthesized from the reactions of equimolar reactions of [RuX 3(EPh 3) 3] and Schiff bases in benzene. The new Ru(III) Schiff base complexes have been characterized by elemental analyses, FT-IR, electronic, 1H NMR and 13C NMR spectra, EPR spectral studies, powder X-ray diffraction (XRD) and electrochemical studies. The new complexes were found to be effective catalysts for aryl-aryl coupling and the oxidation of alcohols into their corresponding carbonyl compounds, respectively, using molecular oxygen atmosphere at ambient temperature. Further, the new Ru(III) Schiff base complexes were screened for their antibacterial activity against Pseudomonas aeruginosa, Vibrio cholera, Salomonella typhi and Staphylococcus aureaus.

  17. Radiolytically prepared Ni-Pd sols as catalysts for water photoreduction

    Energy Technology Data Exchange (ETDEWEB)

    Amouyal, E.; Georgopoulos, M.; Delcourt, M.O. (Paris-11 Univ., 91 - Orsay (FR). Lab. de Physico-Chimie des Rayonnements)

    1989-07-01

    Ni-Pd sols containing 10% Pd, prepared via radiolytic reduction, display a catalytic activity notably enhanced, compared to pure nickel sols, towards the water photoreduction to hydrogen. The test system is Ru(bipy){sub 3}{sup 2+}/methylviologen/N-phenylglycine: a favourable pH effect is shown at pH 2.5. Hydrogen evolution rate is not far from the optimal values obtained with platinum sols in acidic medium. These Ni-Pd aggregates are the first example of an aqueous colloid metal catalyst being improved by alloying effect.

  18. Neonatal RU-486 (mifepristone) exposure increases androgen receptor immunoreactivity and sexual behavior in male rats.

    Science.gov (United States)

    Forbes-Lorman, Robin; Auger, Anthony P; Auger, Catherine J

    2014-01-16

    Progesterone and progestin receptors (PRs) are known to play a role in the development of brain physiology and behavior in many different species. The distribution and regulation of PRs within the developing brain suggest that they likely contribute to the organization of the brain and behavior in a sex-specific manner. We examined the role of PR signaling during development on the organization of adult sexual behavior and androgen receptor (AR) expression in the brain. We administered the PR antagonist, RU-486, subcutaneously to male and female rats on postnatal days 1-7 (0=day of birth) and examined adult sexual behavior and AR-immunoreactivity (AR-ir) in the adult brain. A typical sex difference in lordosis quotient (LQ) was observed and neonatal RU-486 treatment did not alter this behavior. In contrast, neonatal RU-486 treatment increased adult male sexual behavior and AR-ir in several brain areas in males. These data indicate that a transient disruption in PR signaling during development can have lasting consequences on the male brain and may increase male sexual behavior in part by increasing AR expression, and therefore androgen sensitivity, in adulthood.

  19. Reactivity of diaminogermylenes with ruthenium carbonyl: Ru3Ge3 and RuGe2 derivatives.

    Science.gov (United States)

    Cabeza, Javier A; García-Álvarez, Pablo; Polo, Diego

    2011-07-04

    The nature of the products of the reactions of [Ru(3)(CO)(12)] with diaminogermylenes depends upon the volume and the cyclic or acyclic structure of the latter. Thus, the triruthenium cluster [Ru(3){μ-Ge(NCH(2)CMe(3))(2)C(6)H(4)}(3)(CO)(9)], which has a planar Ru(3)Ge(3) core and an overall C(3h) symmetry, has been prepared in quantitative yield by treating [Ru(3)(CO)(12)] with an excess of the cyclic 1,3-bis(neo-pentyl)-2-germabenzimidazol-2-ylidene in toluene at 100 °C, but under analogous reaction conditions, the acyclic and bulkier Ge(HMDS)(2) (HMDS = N(SiMe(3))(2)) quantitatively leads to the mononuclear ruthenium(0) derivative [Ru{Ge(HMDS)(2)}(2)(CO)(3)]. Mixtures of products have been obtained from the reactions of [Ru(3)(CO)(12)] with the cyclic and very bulky 1,3-bis(tert-butyl)-2-germaimidazol-2-ylidene under various reaction conditions. The Ru(3)Ge(3) and RuGe(2) products reported in this paper are the first ruthenium complexes containing diaminogermylene ligands.

  20. Ru-NQR Study for Novel Phase Transition in CeRu2Al10

    Science.gov (United States)

    Matsumura, Masahiro; Tomita, Naoya; Matsuoka, Junichirou; Kishimoto, Yasuki; Kato, Harukazu; Kitagawa, Kentaro; Nishioka, Takashi; Tanida, Hiroshi; Sera, Masafumi

    2014-10-01

    We have performed Ru-NQR measurements on CeRu2Al10 exhibiting novel phase transition at an abnormally high temperature T0 = 27.3 K and on NdRu2Al10 with a magnetic transition temperature Tm = 2.4 K as a reference RKKY system. The splitting of the NQR line due to internal fields below T0 shows a mean-field-like monotonic increase, indicating no change in the magnetic structure below T0. The internal field strength is one order larger than those at Al sites in CeRu2Al10, and is comparable to that at the Ru site in NdRu2Al10 despite the sevenfold smaller magnitude of the 4f moment, being indicative of an enhanced conduction electron polarization at the Ru site. One of the causes of the high T0 might be the enhanced exchange coupling through the Ce-Ru-Ce path mediated by the enhanced conduction electron polarization. Being similar to that in the Al site, the nuclear spin-lattice relaxation rate 1/T1 shows a gap-like decrease below T0 without enhancement owing to a critical slowing down at T0, in contrast to the mean field 2nd-order transition.

  1. Ru(0) and Ru(II) nitrosyl pincer complexes: structure, reactivity, and catalytic activity.

    Science.gov (United States)

    Fogler, Eran; Iron, Mark A; Zhang, Jing; Ben-David, Yehoshoa; Diskin-Posner, Yael; Leitus, Gregory; Shimon, Linda J W; Milstein, David

    2013-10-07

    Despite considerable interest in ruthenium carbonyl pincer complexes and their substantial catalytic activity, there has been relatively little study of the isoelectronic ruthenium nitrosyl complexes. Here we describe the synthesis and reactivity of several complexes of this type as well as the catalytic activity of complex 6. Reaction of the PNP ligand (PNP = 2,6-bis((t)Bu2PCH2)pyridine) with RuCl3(NO)(PPh3)2 yielded the Ru(II) complex 3. Chloride displacement by BAr(F-) (BAr(F-) = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) gave the crystallographicaly characterized, linear NO Ru(II) complex 4, which upon treatment with NaBEt3H yielded the Ru(0) complexes 5. The crystallographically characterized Ru(0) square planar complex 5·BF4 bears a linear NO ligand located trans to the pyridilic nitrogen. Further treatment of 5·BF4 with excess LiOH gave the crystallographicaly characterized Ru(0) square planar, linear NO complex 6. Complex 6 catalyzes the dehydrogenative coupling of alcohols to esters, reaching full conversion under air or under argon. Reaction of the PNN ligand (PNN = 2-((t)Bu2PCH2)-6-(Et2NCH2)pyridine) with RuCl3(NO)(H2O)2 in ethanol gave an equilibrium mixture of isomers 7a and 7b. Further treatment of 7a + 7b with 2 equivalent of sodium isopropoxide gave the crystallographicaly characterized, bent-nitrosyl, square pyramidal Ru(II) complex 8. Complex 8 was also synthesized by reaction of PNN with RuCl3(NO)(H2O)2 and Et3N in ethanol. Reaction of the "long arm" PN(2)N ligand (PN(2)N = 2-((t)Bu2PCH2-)-6-(Et2NCH2CH2)pyridine) with RuCl3(NO)(H2O)2 in ethanol gave complex 9, which upon treatment with 2 equiv of sodium isopropoxide gave complex 10. Complex 10 was also synthesized directly by reaction of PN(2)N with RuCl3(NO)(H2O)2 and a base in ethanol. A noteworthy aspect of these nitrosyl complexes is their preference for the Ru(0) oxidization state over Ru(II). This preference is observed with both aromatized and dearomatized pincer ligands, in

  2. Synthesis and reactivity of the aquation product of the antitumor complex trans-[Ru(III)Cl4(indazole)2]-.

    Science.gov (United States)

    Cebrián-Losantos, Berta; Reisner, Erwin; Kowol, Christian R; Roller, Alexander; Shova, Sergiu; Arion, Vladimir B; Keppler, Bernhard K

    2008-07-21

    Aquation of the investigational anticancer drug trans-[Ru(III)Cl4(Hind)2](-) (1, KP1019) results in the formation of mer,trans-[Ru(III)Cl3(Hind)2(H2O)] (2), which was isolated in high yield (85%) and characterized by spectroscopic methods and X-ray crystallography. Dissolution of 2 in acetone, led to its dimerization into [Ru(III)2(mu-Cl)2Cl4(Hind)4] x 2 (Me)2CO (3) in 79% yield, with release of two water molecules. Complex 2 reacts readily with nucleophilic organic molecules, viz., methanol or dimethyl sulfide, at room temperature by replacement of the aqua ligand to give mer,trans-[Ru(III)Cl3(Hind)2(MeOH)] (4) and mer,trans-[Ru(III)Cl3(Hind)2(Me2S)] (5) in 58 and 64% yield, respectively. By reaction of 2 with DMSO at room temperature or dimethyl sulfide at elevated temperatures trans,trans,trans-[Ru(II)Cl2(Hind)2(Me2S)2] (6) and trans,trans,trans-[Ru(II)Cl2(Hind)2(S-DMSO)2] (7) were prepared in 64 and 75% yield, respectively. Dissolution of 2 in acetonitrile or benzonitrile gave rise to mer,trans-[Ru(III)Cl3(Hind)(HNC(Me)ind)] (8a), mer,trans-[Ru(III)Cl3(Hind)(HNC(Ph)ind)] (8b), and trans,trans-[Ru(III)Cl2(HNC(Me)ind)2]Cl (9) in 67, 50, and 23% yield, respectively, upon metal-assisted iminoacylation of indazole, which is unprecedented for ruthenium(III). Furthermore, complex 2 reacts with the DNA-model bases 9-methyladenine (9-meade) and N6,N6-dimethyladenine (6-me2ade) to yield mer,trans-[Ru(III)Cl3(Hind)2(9-meade)] (10) and mer,trans-[Ru(III)Cl3(Hind)2(6-me2ade)] (11) with the purine bases bound to the Ru(III) center via N7 and N3, respectively. Complex 11 represents the first ruthenium complex in which the coordination of the purine ligand N6,N6-dimethyladenine occurs via N3. In addition, the polymer [Na(EtOAc)2Ru(III)(mu-Cl)4(Hind)2]n (12) was crystallized from ethyl acetate/diethyl ether solutions of Na[trans-Ru(III)Cl4(Hind)2] x 1.5 H2O (1a). The reported complexes were characterized by elemental analysis, IR and UV-vis spectroscopy, ESI mass spectrometry

  3. Carbon supported nanoparticles Pt Ru (Pt Ru/C electrocatalysts) prepared using electron beam irradiation; Preparacao de nanoparticulas de PtRu suportadas em carbono (eletrocatalisadores PtRu/C) utilizando feixe de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F. da; Oliveira Neto, Almir; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Programa de Celulas a Combustivel], e-mail: espinace@ipen.br, e-mail: dfsilva@ipen.br

    2006-07-01

    Carbon-supported Pt Ru (electrocatalysts PtRu/C nanoparticles) were prepared submitting a water/ethylene glycol mixture containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The PtRu/C electrocatalysts were characterized by EDX, XRD and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained PtRu/C electrocatalysts were more active for methanol electro-oxidation than the commercial PtRu/C ETEK electrocatalyst at ambient temperature. (author)

  4. Carbon supported nanoparticles Pt Ru (Pt Ru/C electrocatalysts) prepared using electron beam irradiation; Preparacao de nanoparticulas de PtRu suportadas em carbono (eletrocatalisadores PtRu/C) utilizando feixe de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F. da; Oliveira Neto, Almir; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Programa de Celulas a Combustivel], e-mail: espinace@ipen.br, e-mail: dfsilva@ipen.br

    2006-07-01

    Carbon-supported Pt Ru (electrocatalysts PtRu/C nanoparticles) were prepared submitting a water/ethylene glycol mixture containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The PtRu/C electrocatalysts were characterized by EDX, XRD and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained PtRu/C electrocatalysts were more active for methanol electro-oxidation than the commercial PtRu/C ETEK electrocatalyst at ambient temperature. (author)

  5. High performance Pd-based catalysts for oxidation of formic acid

    Science.gov (United States)

    Wang, Rongfang; Liao, Shijun; Ji, Shan

    Two novel catalysts for anode oxidation of formic acid, Pd 2Co/C and Pd 4Co 2Ir/C, were prepared by an organic colloid method with sodium citrate as a complexing agent. These two catalysts showed better performance towards the anodic oxidation of formic acid than Pd/C catalyst and commercial Pt/C catalyst. Compared with Pd/C catalyst, potentials of the anodic peak of formic acid at the Pd 2Co/C and Pd 4Co 2Ir/C catalyst electrodes shifted towards negative value by 140 and 50 mV, respectively, meanwhile showed higher current densities. At potential of 0.05 V (vs. SCE), the current density for Pd 4Co 2Ir/C catalyst is as high as up to 13.7 mA cm -2, which is twice of that for Pd/C catalyst, and six times of that for commercial Pt/C catalyst. The alloy catalysts were nanostructured with a diameter of ca. 3-5 nm and well dispersed on carbon according to X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements. The composition of alloy catalysts was analyzed by energy dispersive X-ray analysis (EDX). Pd 4Co 2Ir/C catalyst showed the highest activity and best stability making it the best potential candidate for application in a direct formic acid fuel cell (DFAFC).

  6. Syntheses and molecular structures of novel Ru(II) complexes with bidentate benzimidazole based ligands and their catalytic efficiency for oxidation of benzyl alcohol

    Science.gov (United States)

    Dayan, Osman; Tercan, Melek; Özdemir, Namık

    2016-11-01

    Five bidentate ligands derived from quinoline-2-carboxylic acid, i.e. 2-(1H-benzimidazol-2-yl)quinoline (L1), 2-(1-benzyl-1H-benzimidazol-2-yl)quinoline (L2), 2-[1-(2,3,5,6-tetramethylbenzyl)-1H-benzimidazol-2-yl]quinoline (L3), 2-[1-(4-chlorobenzyl)-1H-benzimidazol-2-yl]quinoline (L4), and 2-[1-(4-methylbenzyl)-1H-benzimidazol-2-yl]quinoline (L5) were synthesized. Treatment of L1-5 with [RuCl2(p-cymene)]2 and KPF6 afforded six-coordinate piano-stool Ru(II) complexes, namely, [RuCl(L1)(p-cymene)]PF6 (C1), [RuCl(L2)(p-cymene)]PF6 (C2), [RuCl(L3)(p-cymene)]PF6 (C3), [RuCl(L4)(p-cymene)]PF6 (C4), and [RuCl(L5)(p-cymene)]PF6 (C5). Synthesized compounds were characterized with different techniques such as 1H and 13C NMR, FT-IR, and UV-vis spectroscopy. The solid state structure of L1 and C3 was confirmed by single-crystal X-ray diffraction analysis. The single crystal structure of C3 verified coordination of L3 to the Ru(II) center. The Ru(II) center has a pseudo-octahedral three legged piano stool geometry. The complexes C1-5 were tested as catalysts for the catalytic oxidation of benzyl alcohol to benzaldehyde in the presence of periodic acid (H5IO6) (Substrate/Catalyst/Oxidant = 1/0.01/0.5). The best result was obtained with C2 (3 h→90%).

  7. Al 2O 3 supported Ru catalysts prepared by thermolysis of Ru 3(CO) 12 for catalytic wet air oxidation

    Science.gov (United States)

    Yu, Chaoying; Zhao, Peiqing; Chen, Gexin; Hu, Bin

    2011-06-01

    Low loading catalysts Ru/γ-Al 2O 3 and Ru-Ce/γ-Al 2O 3 were prepared by thermolysis of Ru 3(CO) 12 on γ-Al 2O 3. The catalysts were characterized by XPS, XRD and SEM. Two new Ru species (Ru A and Ru B) were detected during the Ru 3(CO) 12 decomposition process due to chemical interaction with the active OH groups on the surface of Al 2O 3 support, and the reduction of them can lead to more dispersed metallic phases. The sample was completely decomposed at 673 K in H 2, and RuO 2 was formed with minor amounts of Ru 0. When the temperature was increased to 773 K to heat the sample, the ratio of Ru 0 to RuO 2 increased. However, after the addition of CeO 2, only RuO 2 was detected on surface. The catalysts exhibited high activities in Catalytic Wet Air Oxidation (CWAO) of different organic compounds at high concentration such as isopropyl alcohol, phenol, acetic acids and N,N-dimethylformamide, which is attributed to the better dispersion of Ru particles and the addition of CeO 2 further enhanced number of effectively active sites on the cluster-derived catalyst surface.

  8. Shape transitions in neutron-rich Ru isotopes: spectroscopy of 109,110,111,112Ru

    Energy Technology Data Exchange (ETDEWEB)

    Hua, H; Cline, D; Hayes, A B; Teng, R; Riley, D; Clark, R M; Fallon, P; Goergen, A; Macchiavelli, A O; Vetter, K

    2005-06-29

    The spectroscopy of neutron-rich {sup 109,110,111,112}Ru nuclei was studied by measuring the prompt {gamma} rays originated from fission fragments, produced by the {sup 238}U({alpha},f) fusion-fission reaction, in coincidence with the detection of both fragments. For {sup 109,111}Ru, both the negative-parity (h{sub 11/2} orbitals) and positive-parity (g{sub 7/2} and/or d{sub 5/2} orbitals) bands were extended to substantially higher spin and excitation energy than known previously. The ground-state and {gamma}-vibrational bands of {sup 110,112}Ru also were extended to higher spin, allowing observation of the second band crossing at the rotational frequency of {approx}450 keV in {sup 112}Ru, which is {approx}50 keV above the first band crossing. At a similar rotational frequency, the first band crossing for the h{sub 11/2} band in {sup 111}Ru was observed, which is absent in {sup 109}Ru. These band crossings most likely are caused by the alignment of the g{sub 9/2} proton pair. This early onset of the band crossing for the aligned {pi}g{sub 9/2} orbitals may be evidence of a triaxial shape transition from prolate to oblate occurring in {sup 111}Ru. The data together with a comparison of cranked shell model predictions are presented.

  9. IOT Overview: IR Instruments

    Science.gov (United States)

    Mason, E.

    In this instrument review chapter the calibration plans of ESO IR instruments are presented and briefly reviewed focusing, in particular, on the case of ISAAC, which has been the first IR instrument at VLT and whose calibration plan served as prototype for the coming instruments.

  10. Comparison of hydration reactions for "piano-stool" RAPTA-B and [Ru(η6- arene)(en)Cl]+ complexes: Density functional theory computational study

    Science.gov (United States)

    Chval, Zdeněk; Futera, Zdeněk; Burda, Jaroslav V.

    2011-01-01

    The hydration process for two Ru(II) representative half-sandwich complexes: Ru(arene)(pta)Cl2 (from the RAPTA family) and [Ru(arene)(en)Cl]+ (further labeled as Ru_en) were compared with analogous reaction of cisplatin. In the study, quantum chemical methods were employed. All the complexes were optimized at the B3LYP/6-31G(d) level using Conductor Polarizable Continuum Model (CPCM) solvent continuum model and single-point (SP) energy calculations and determination of electronic properties were performed at the B3LYP/6-311++G(2df,2pd)/CPCM level. It was found that the hydration model works fairly well for the replacement of the first chloride by water where an acceptable agreement for both Gibbs free energies and rate constants was obtained. However, in the second hydration step worse agreement of the experimental and calculated values was achieved. In agreement with experimental values, the rate constants for the first step can be ordered as RAPTA-B > Ru_en > cisplatin. The rate constants correlate well with binding energies (BEs) of the Pt/Ru-Cl bond in the reactant complexes. Substitution reactions on Ru_en and cisplatin complexes proceed only via pseudoassociative (associative interchange) mechanism. On the other hand in the case of RAPTA there is also possible a competitive dissociation mechanism with metastable pentacoordinated intermediate. The first hydration step is slightly endothermic for all three complexes by 3-5 kcal/mol. Estimated BEs confirm that the benzene ligand is relatively weakly bonded assuming the fact that it occupies three coordination positions of the Ru(II) cation.

  11. IR Hot Wave

    Energy Technology Data Exchange (ETDEWEB)

    Graham, T. B.

    2010-04-01

    The IR Hot Wave{trademark} furnace is a breakthrough heat treatment system for manufacturing metal components. Near-infrared (IR) radiant energy combines with IR convective heating for heat treating. Heat treatment is an essential process in the manufacture of most components. The controlled heating and cooling of a metal or metal alloy alters its physical, mechanical, and sometimes chemical properties without changing the object's shape. The IR Hot Wave{trademark} furnace offers the simplest, quickest, most efficient, and cost-effective heat treatment option for metals and metal alloys. Compared with other heat treatment alternatives, the IR Hot Wave{trademark} system: (1) is 3 to 15 times faster; (2) is 2 to 3 times more energy efficient; (3) is 20% to 50% more cost-effective; (4) has a {+-}1 C thermal profile compared to a {+-}10 C thermal profile for conventional gas furnaces; and (5) has a 25% to 50% smaller footprint.

  12. Temperature-induced transformation of electrochemically formed hydrous RuO2 layers over Ru(0001) model electrodes

    Science.gov (United States)

    Krause, Philipp P. T.; Camuka, Hava; Leichtweiss, Thomas; Over, Herbert

    2016-07-01

    Hydrous RuO2 reveals excellent performance both as a supercapacitor and as a heterogeneous oxidation catalyst. Molecular understanding of these processes needs, however, a model system with preferably low structural and morphological complexity. This goal is partly accomplished here by using single crystalline Ru(0001) as a template on which hydrous RuO2 is electrochemically formed. The hydrous RuO2 layers on Ru(0001) and their temperature induced transformation under ultra high vacuum (UHV) conditions are comprehensively characterized by scanning electron microscopy and X-ray photoemission spectroscopy. The hydrous RuO2 layer grows with an intricate morphology governed by the presence of step bunching regions of the Ru(0001) surface. Upon annealing to 200 °C in UHV the hydrous RuO2 layer transforms mostly into flat metallic Ru islands and occasionally into (100) and (111) oriented RuO2 particles aligned along the high symmetry direction of Ru(0001).Hydrous RuO2 reveals excellent performance both as a supercapacitor and as a heterogeneous oxidation catalyst. Molecular understanding of these processes needs, however, a model system with preferably low structural and morphological complexity. This goal is partly accomplished here by using single crystalline Ru(0001) as a template on which hydrous RuO2 is electrochemically formed. The hydrous RuO2 layers on Ru(0001) and their temperature induced transformation under ultra high vacuum (UHV) conditions are comprehensively characterized by scanning electron microscopy and X-ray photoemission spectroscopy. The hydrous RuO2 layer grows with an intricate morphology governed by the presence of step bunching regions of the Ru(0001) surface. Upon annealing to 200 °C in UHV the hydrous RuO2 layer transforms mostly into flat metallic Ru islands and occasionally into (100) and (111) oriented RuO2 particles aligned along the high symmetry direction of Ru(0001). Electronic supplementary information (ESI) available. See DOI: 10

  13. A green approach to ethyl acetate: Quantitative conversion of ethanol through direct dehydrogenation in a Pd-Ag membrane reactor

    KAUST Repository

    Zeng, Gaofeng

    2012-11-07

    Pincers do the trick: The conversion of ethanol to ethyl acetate and hydrogen was achieved using a pincer-Ru catalyst in a Pd-Ag membrane reactor. Near quantitative conversions and yields could be achieved without the need for acid or base promoters or hydrogen acceptors (see scheme). © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Facile preparation of Pd-metal oxide/C electrocatalysts and their application in the electrocatalytic oxidation of ethanol

    Science.gov (United States)

    Abdel Hameed, R. M.

    2017-07-01

    Palladium nanoparticles were deposited on different metal oxide/C supports using a mixture of ethylene glycol and sodium borohydride during the reduction step. The electrocatalytic activity of Pd-based electrocatalysts was investigated for ethanol oxidation in alkaline medium. More negative onset potential and peak potential values for ethanol oxidation were shown at Pd-metal oxide/C electrocatalysts when compared to those at Pd/C. The oxidation current density recorded decay percentage of 84.44% at Pd-SnO2/C compared to 48% at Pd/C during the stability test. Adding MnO2, V2O5, RuO2 or SnO2 to Pd/C enhanced its charge transfer properties by 1.91, 4.77, 5.05 or 6.23 times.

  15. Contribution à la cristallochimie des isotypes de ThCr2Si2 et CaBe2Ge2 . II. Variation des distances interatomiques dans des germaniures MM'2Ge2 de type ThCr2Si2 (M = Y, Nd, Ca; M' = Mn, Cu, Ru, Rh, Pd, Ir)

    Science.gov (United States)

    Venturini, G.; Malaman, B.; Roques, B.

    1989-03-01

    The ThCr 2Si 2-type structures determined in this work make use of all their variable parameters, a, c, and zGe, to adjust to the size and/or electronic properties of their components. The M'-Ge bonds are very strong, except for M' = Mn; most structures adjust to the M size, while preserving their layers of M'-centered Ge tetrahedra. The strength of the interlayer GeGe bonds depends on the electronic structure of the M' atoms. It increases strongly when M' moves to the right of the transition metal series. The GeGe bonding strength determines the shape of the Ge-centered M4M' 4 square antiprisms and, consequently, the a, c, and zGe values. The results are discussed, referring to the band model of R. Hoffmann and C. Zheng ( J. Phys. Chem.89, 4175 (1985)).

  16. Crystal Structure and Characterization of Pd(Ⅱ) Bis(diisopropyldithiocarbamate) Complex

    Institute of Scientific and Technical Information of China (English)

    XU, Liang-Zhong; ZHAO, Pu-Su; ZHANG, Shu-Sheng

    2001-01-01

    The crystal and molecular structure of [Pd(iPr2 dtc)2] (dtc=dithiocarbamate) have been determined by X-ray crystallography. The unit cell of the crystal structure consists of two discrete monomeric molecules of [Pd(iPr2dtc)2]. The Pd(Ⅱ)ion has an square-planar. The electronic and IR spectral data are in agreement with the X-ray structure. The TG data indicate slight degradation of a few percent.

  17. Supercapacitive performance of hydrous ruthenium oxide (RuO2.H2O) thin films synthesized by chemical route at low temperature

    Indian Academy of Sciences (India)

    P R Deshmukh; S N Pusawale; R N Bulakhe; C D Lokhande

    2013-12-01

    In the present investigation, we report the synthesis of ruthenium oxide (RuO2.H2O) thin films by simple chemical bath deposition (CBD) method at low temperature on the stainless steel substrate. The prepared thin films are characterized for their structural and morphological properties by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR) and scanning electron microscopy (SEM). The structural study revealed that the ruthenium oxide thin films are amorphous. Scanning electron microscopy study shows compact morphology with small overgrown particles on the surface of the substrate. FT–IR study confirms the formation of RuO2.H2O material. The supercapacitor behaviour of RuO2.H2O thin film was studied using cyclic voltammetry (CV) technique in 0.5 M H2SO4 electrolyte. RuO2.H2O film showed maximum specific capacitance of 192 F.g-1 at a scan rate of 20 mV.s-1. The charge–discharge studies of RuO2.H2O carried out at 300 A.cm-2 current density revealed the specific power of 1.5 kW.kg-1 and specific energy of 41.6Wh.kg-1 with 95% coulombic efficiency.

  18. A general route for RuO2 deposition on metal oxides from RuO4

    DEFF Research Database (Denmark)

    Kleiman-Shwarsctein, Alan; Laursen, Anders Bo; Cavalca, Filippo;

    2012-01-01

    A novel method for the deposition of RuO2 from RuO4(g) on diverse metal oxides has been developed by grafting dopamine onto the otherwise un-reactive metal oxide surface. Oxygen evolution reaction on TiO2 and the photoelectrochemical improvement of WO3 by deposition of RuO2 are just a few examples...

  19. Evolution of structure, magnetism, and electronic transport in the doped pyrochlore iridate Y2Ir2 -xRuxO7

    Science.gov (United States)

    Kumar, Harish; Dhaka, R. S.; Pramanik, A. K.

    2017-02-01

    The interplay between spin-orbit coupling (SOC) and electron correlation (U ) is considered for many exotic phenomena in iridium oxides. We have investigated the evolution of structural, magnetic, and electronic properties in the pyrochlore iridate Y2Ir2 -xRuxO7 where the substitution of Ru has been aimed to tune this interplay. The Ru substitution does not introduce any structural phase transition, however, we do observe an evolution of lattice parameters with the doping level x . X-ray photoemission spectroscopy (XPS) study indicates Ru adopts the charge state of Ru4 + and replaces the Ir4 + accordingly. Magnetization data reveal both the onset of magnetic irreversibility and the magnetic moment decreases with progressive substitution of Ru. These materials show a nonequilibrium low temperature magnetic state as revealed by magnetic relaxation data. Interestingly, we find the magnetic relaxation rate increases with substitution of Ru. The electrical resistivity shows an insulating behavior in the whole temperature range, however, resistivity decreases with the substitution of Ru. The nature of electronic conduction has been found to follow power-law behavior for all the materials.

  20. Electrooxidation of CO on Ru(0001) and RuO2(100) Electrode Surfaces

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The electrooxidation of CO on Ru (0001) and RuO2 (100) electrode surfaces were characterized by cyclic voltammetry, AES and RHEED. The CO adlayer was first partially oxidized at 0.8 V, which is controlled by the attack of oxygen species toward the Ru(0001) surface. The remaining CO adlayer oxidation at 0.55 V is related to the combination of CO molecules with oxygen species already located on the surface. In contrast, successive peaks on RuO2(100) at 0.4 V and 0.72 V are observed, which shows that CO molecules can directly react with two different lattice-oxygen on the surface to carbon dioxide.

  1. High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

    Institute of Scientific and Technical Information of China (English)

    MAO Ping; ZHANG Zhi-Gang; PAN Li-Yang; XU Jun; CHEN Pei-Yi

    2009-01-01

    @@ Stacked ruthenium (Ru) nanocrystals (NCs) are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density (3×1012 cm-2 ), small size (2-4 nm) and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs.

  2. Carbon coated face-centered cubic Ru-C nanoalloys.

    Science.gov (United States)

    Zhao, Zhisheng; Meng, Chuanmin; Li, Peifang; Zhu, Wenjun; Wang, Qianqian; Ma, Yanming; Shen, Guoyin; Bai, Ligang; He, Hongliang; He, Duanwei; Yu, Dongli; He, Julong; Xu, Bo; Tian, Yongjun

    2014-09-07

    Carbon-encapsulated ruthenium-carbon (Ru-C) nanoalloys were synthesized by dynamic shocks. The Ru-C alloy shows a new fcc structure different from the original hcp structure of metal Ru. This fcc phase is assigned to a Ru32C4 solid solution with a lattice parameter of 3.868(2) Å and a bulk modulus KT0 of 272(12) GPa. The small amount of carbon in the solid solution enhances the thermodynamic and chemical stabilities with respect to pure Ru, as well as induces changes in the electronic properties, which have direct applications in improving the material's catalytic activity and selectivity.

  3. CO oxidation on fully oxygen covered Ru(0001)

    DEFF Research Database (Denmark)

    Sljivancanin, Zeljko; Hammer, Bjørk

    2010-01-01

    We present a reaction mechanism for CO oxidation at the Ru(0001)-(1×1) surface. By means of density-functional theory studies, we compare the reactivity of flat and stepped regions of the Ru(0001). We find that at saturation oxygen coverage, where the flat parts are unreactive toward CO adsorption...... an intricate reaction pathway for CO adsorption and CO2 formation exists at the monatomic Ru step. By suggesting an efficient mechanism for CO oxidation on nonoxidic Ru, our results offer an explanation for the controversy in the experimental literature regarding how nonoxidic Ru may be as active in CO...

  4. Pt Ru/C electrocatalysts prepared using electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio Furtunato da; Oliveira Neto, Almir; Pino, Eddy Segura; Brandalise, Michele; Linardi, Marcelo; Spinace, Estevam Vitorio [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: espinace@ipen.br

    2007-10-15

    Pt Ru/C electrocatalysts (carbon-supported Pt Ru nanoparticles) were prepared submitting water/ethylene glycol mixtures containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The electrocatalysts were characterized by energy dispersive X ray analysis (EDX), X ray diffraction (XRD) and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained Pt Ru/C electrocatalysts showed superior performance for methanol electro-oxidation at room temperature compared to commercial Pt Ru/C electrocatalyst. (author)

  5. Valence modulations in CeRuSn

    NARCIS (Netherlands)

    Feyerherm, R.; Dudzik, E.; Prokeš, K.; Mydosh, J.A.; Huang, Y.K.; Pöttgen, R.

    2014-01-01

    CeRuSn exhibits an extraordinary room temperature structure at 300 K with the coexistence of two types of Ce ions, namely trivalent Ce3+ and intermediate-valent Ce(4−δ)+, in a metallic environment. The ordered arrangement of these two Ce types on specific crystallographic sites results in a doubling

  6. Electroreflectance study of RuSe 2

    Science.gov (United States)

    Huang, Y. S.; Lin, S. S.; Sheu, J. S.; Shen, W. M.; Pollak, Fred H.

    1990-12-01

    We report the first electrolyte-electroreflectance (EER) study of a RuSe 2 single crystal in the photon energy region of 0.9-5.5 eV. The EER spectrum exhibits differential like structure in the vicinity of interband transitions. The transition energies are determined accurately. A probable energy-band structure is constructed.

  7. Ruthenium redox equilibria: 1. Thermodynamic stability of Ru(III and Ru(IV hydroxides

    Directory of Open Access Journals (Sweden)

    Igor Povar

    2016-04-01

    Full Text Available On the basis of the selected thermodynamic data for Ru(III and Ru(IV compounds in addition to original thermodynamic and graphical approach used in this paper, the thermodynamic stability areas of sparingly soluble hydroxides as well as the repartition of their soluble and insoluble chemical species towards the solution pH and initial concentrations of ruthenium in heterogeneous mixture solid phase–saturated solution have been investigated. By means of the ΔG–pH diagrams, the areas of thermodynamic stability of Ru(III and Ru(IV hydroxides have been established for a number of analytical concentrations in heterogeneous mixtures. The diagrams of heterogeneous and homogeneous chemical equilibria have been used for graphical representation of complex equilibria in aqueous solutions containing Ru(III and Ru(IV. The obtained results, based on the thermodynamic analysis and graphic design of the calculated data in the form of the diagrams of heterogeneous chemical equilibria, are in good agre­ement with the available experimental data.

  8. Lubiprostone: RU 0211, SPI 0211.

    Science.gov (United States)

    2005-01-01

    Lubiprostone [RU 0211, SPI 0211] is a bicyclic fatty acid that acts as a chloride channel opener, increasing intestinal water secretion. Lubiprostone, an orally-administered formulation, is one of a series of functional fatty acid compounds discovered by Dr Ryuji Ueno, and is currently undergoing development for the treatment of constipation, constipation-predominant irritable bowel syndrome (IBS-C) and postoperative ileus with Sucampo Pharmaceutical's. Lubiprostone activates a specific chloride channel (CLC2) on cells lining the gut, thereby naturally increasing intestinal fluid secretion. The increased fluid level softens the stool, promotes spontaneous bowel movements, and reduces abdominal discomfort/pain and bloating. The chloride channel is a protein that controls cell membrane transport of chloride ion. Lubiprostone acts on the ClC-2 chloride channel, which is located in the apical intestinal membrane. In November 2004, Takeda Pharmaceuticals entered into a collaboration and licensing agreement for Lubiprostone with Sucampo Pharmaceuticals for the treatment of chronic constipation and constipation-predominant Irritable Bowel Syndrome (c-IBS). Under the terms of the agreement, Takeda received the right to market the product in the US and Canada, while Sucampo reserved the co-promotion rights for these countries. Takeda's wholly-owned US subsidiary, Takeda Pharmaceuticals North America Inc., will sell lubiprostone once the product is approved by the US FDA. Takeda will also receive an option for marketing rights in other territories, including Japan and Europe. Takeda and Sucampo agreed on the exclusive manufacturing and supply of Lubiprostone by R-Tech Ueno, Ltd, a member of the Sucampo Group. Sucampo has the potential to receive up to dollar US 210 million in initial and milestone payments, some of which are contingent upon the successful achievement of several milestones. Takeda will fund a major part of development costs not only for chronic constipation

  9. Factorial PD-Clustering

    CERN Document Server

    Tortora, Cristina; Summa, Mireille Gettler

    2011-01-01

    Factorial clustering methods have been developed in recent years thanks to the improving of computational power. These methods perform a linear transformation of data and a clustering on transformed data optimizing a common criterion. Factorial PD-clustering is based on Probabilistic Distance clustering (PD-clustering). PD-clustering is an iterative, distribution free, probabilistic, clustering method. Factorial PD-clustering make a linear transformation of original variables into a reduced number of orthogonal ones using a common criterion with PD-Clustering. It is demonstrated that Tucker 3 decomposition allows to obtain this transformation. Factorial PD-clustering makes alternatively a Tucker 3 decomposition and a PD-clustering on transformed data until convergence. This method could significantly improve the algorithm performance and allows to work with large dataset, to improve the stability and the robustness of the method.

  10. Novel Ru(III) Complexes with Some Benzothiazole Derivatives: Synthesis, Physicochemical and Pharmacological Investigations.

    Science.gov (United States)

    Nikolova, A; Momekov, G; Bakalova, A; Nikolova, K; Ivanov, D

    2015-06-01

    In this work we present 3 new complexes of Ruthenium (III) with a general formula HL[Ru(L)2Cl4], where L=benzothiazole, 2-methylbenzothiazole and 2-mercaptobenzothiazole. The syntheses were carried out in polar medium under argon. The compounds obtained were characterised by IR-, (1)H-NMR- (13)C-NMR-, UV-VIS-spectroscopy and conductivity measurements. The ligands behaved as monodentate, bounding Ru(III) through the nitrogen atoms from the heterocycle. The cytotoxicity of the new complexes was tested against 2 human leukemic cell lines (K-562 and KE-37), using the MTT-dye reduction assay. The Ru(III) coordination compound with 2-methylbenzothiazole displayed superior activity compared to the other novel complexes. Its IC50 values were comparable to that of the reference cytotoxic drug cisplatin. In general, the ligands displayed only marginal inhibitory effects on the human leukemic cell lines. Moreover, the ability of the complexes to trigger apoptosis was evaluated using a commercially available DNA-fragmentation ELISA kit and the obtained data indicated that their proapoptotic effects well correlate to the MTT-bioassay data.

  11. Improved sulfur-resistant ability on CO oxidation of Pd/Ce0.75Zr0.25O2 over Pd/CeO2-TiO2 and Pd/CeO2

    Institute of Scientific and Technical Information of China (English)

    沈美庆; 林放; 魏光曦; 王建强; 朱少春

    2015-01-01

    The influence of sulfation on Pd/Ce0.75Zr0.25O2, Pd/CeO2-TiO2 and Pd/CeO2 was investigated. Physical structure and chemical properties of different catalysts were characterized by N2 adsorption, X-ray diffraction (XRD), CO chemisorption, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and X-ray fluorescence (XRF). After 10 h SO2 sulfation, it was found that the decrement on CO oxidation catalytic activity was limited on Pd/Ce0.75Zr0.25O2 compared to Pd/CeO2-TiO2 and Pd/CeO2. It demonstrated that Pd/Ce0.75Zr0.25O2 was more sulfur resistant compared to the other two catalysts. Af-ter sulfur exposure, catalyst texture was not much influenced as shown by N2 adsorption and XRD, and surface Pd atoms were poi-soned indicated by CO chemisorption results. Pd/Ce0.75Zr0.25O2 and Pd/CeO2-TiO2 exhibited less sulfur accumulation compared to Pd/CeO2 in the sulfation process. Furthermore, XPS results clarified that surface sulfur amount, especially surface sulfates amount on the sulfated catalysts was more crucial for the deactivation in sulfur containing environment.

  12. Thermochemical behaviour of Ru(II) complex–SiO2 microcomposites

    Indian Academy of Sciences (India)

    S Anastasova; M Milanova; I Manolov; T Czeppe; D Todorovsky

    2007-10-01

    The results from DSC and thermogravimetric analysis of gels produced from a mixture of tetraethoxysilane (TEOS) and octyltriethoxysilane (OtEOS) both with and without immobilized Ru(II) tris(4,7-diphenyl-1,10-phenanthroline) dichloride as well as DSC and TG data for films deposited by deep- or spincoating from the same gels, are reported. The initial products are characterized by elemental analysis, IR, solid state NMR and mass spectroscopy. Elemental analysis and IR spectroscopy are applied for identification of some of the intermediates obtained after heating at different temperatures. The final products are characterized by X-ray diffractometry. A hypothesis for the thermodecomposition processes taking place is proposed. The results reported contribute to elucidation of the properties as well as the temperature intervals in which the studied microcomposites could be used as sensing components of oxygen sensors.

  13. Phototriggered sulfoxide isomerization in [Ru(pic)2(dmso)2].

    Science.gov (United States)

    Rachford, Aaron A; Petersen, Jeffrey L; Rack, Jeffrey J

    2007-08-14

    We report the characterization and photochemistry of a simple ruthenium coordination complex containing only picolinate (pic) and dmso, which exhibits a large isomerization quantum yield (Phi(SS-->OO) = 0.50) in various solvents. The picolinate ligands of [Ru(pic)(2)(dmso)(2)] are in a cis arrangement so that the carboxylate oxygen of one pic ligand (O1) is trans to the pyridine of the second picolinate (N2). One dmso ligand (S1) is trans to a pyridine nitrogen (N1), while the second dmso (S2) is trans to a carboxylate oxygen (O3). The cyclic voltammetry, (1)H NMR, IR, and UV-vis spectroscopy data suggest that while both dmso ligands isomerize photochemically, only one dmso ligand isomerizes electrochemically. Isomerization quantum yields for each dmso ligand differ by an order of magnitude (Phi(SS-->SO) = 0.46 and Phi(SO-->OO) = 0.036). In agreement with previous results, the isomerization quantum yield for each dmso is dependent on the ligand that is trans to the dmso.

  14. A redox-active porous coordination network film based on a Ru complex as a building block on an ITO electrode.

    Science.gov (United States)

    Shinomiya, Takuya; Ozawa, Hiroaki; Mutoh, Yuichiro; Haga, Masa-Aki

    2013-12-01

    The combination of self-assembled monolayer (SAM) and layer-by-layer (LbL) growth methods for the construction of a surface porous film has the potential to incorporate a wide range of chemical functionalities on a solid surface. A novel redox-active Ru complex with 2,6-bis(N-pyridylbenzimidazolyl)-pyridine ligands (Ru complex 1), in which four peripheral pyridine groups act as coordination sites, was used as a building block for a porous coordination network film. By using (4-pyridyl)phenylphosphonic acid as a SAM primer layer on an ITO surface, the Ru complex 1 was immobilized by the successive reaction of PdCl2 on the ITO electrode in the LbL growth method. Multilayer growth was monitored by UV-vis spectra and cyclic voltammetry, in which the linear increases of both absorbance and the peak current were observed. This result indicated that the regular accumulation of Ru complex 1 onto the ITO surface took place. The permselectivity of the present porous coordination network structure was examined using redox-active molecular probes with different sizes and charges such as ferrocene, trimethylaminomethylferrocene, the Os bis(2,6-bis(N-methylbenzimidazolyl)-pyridine) complex, and tetrathiofulvarene (TTF). With the Os complex and cationic ferrocene, only the catalytic peak was observed as a prewave of the adsorbed Ru(II/III) peak at +0.73 V. On the other hand, the oxidation peak of ferrocene was observed around 0 V vs. Fc(+)/Fc even for nine-layered films in addition to the adsorbed Ru(II/III) peak. From these results, not only molecular size but also electrostatic interaction plays an important role in the permeation into the Ru complex 1 porous network film.

  15. Green synthesis of Pd@graphene nanocomposite: Catalyst for the selective oxidation of alco

    Directory of Open Access Journals (Sweden)

    Abdulhadi H. Al-Marri

    2016-11-01

    Full Text Available Due to their excellent physicochemical properties and synergistic effect, graphene metallic NPs based nanocomposites have gained significant attention in various technological fields including catalysis. Here we demonstrate a single pot, facile and environmental friendly synthesis of catalytically active palladium(Pd@graphene nanocomposites (SP-HRG-Pd by the simultaneous reduction of graphene oxide (GRO and PdCl2 using Salvadora persica L. (miswak root extract (RE as bioreductant. The synthesis of SP-HRG-Pd was confirmed by various spectroscopic and microscopic techniques, including ultraviolet–visible (UV–vis, Fourier-transform infrared (FT-IR, Raman and X-ray photoelectron (XPS spectroscopy, X-ray powder diffraction (XRD and transmission electron microscopy (TEM. The polyphenolic (flavonoids and terpenoids rich contents of the miswak RE not only facilitated the reduction of graphene oxide and PdCl2 but also ensured the homogeneous binding of the Pd NPs on graphene, and through stabilization of the surface of SP-HRG-Pd nanocomposites. This also led to the enhanced dispersibility of as synthesized nanocomposites in aqueous solutions. The as-prepared SP-HRG-Pd nanocomposites also demonstrated excellent catalytic activity toward the selective oxidation of aromatic alcohols. Furthermore, in order to study the effect of calcination temperature and concentration of Pd NPs on the catalytic activities of nanocomposites, different samples of SP-HRG-Pd nanocomposites containing different amounts of Pd using various concentrations of Pd precursor were prepared and calcined at various temperatures.

  16. 19. gadsimta īru gotiskās literatūras īpatnības

    OpenAIRE

    Tepļakova, Ksenija

    2013-01-01

    Īru gotiskā literatūra, viens no gotiskās literatūras žanriskajiem strāvojumiem, piedzīvoja savus ziedu laikus 19.gadsimtā, kad radās tādu plaši pazīstamu īru rakstnieku kā Čārlza Roberta Metjurina, Džozefa Šeridana le Fanu un Brema Stokera darbi. Maģistra darba mērķis ir izpētīt 19.gadsimta īru gotiskās literatūras nozīmi gotiskās literatūras žanra ietvaros un identificēt īru gotiskās literatūras fenomenu. Darbs sniedz īsu pārskatu par gotisko literatūru un tās galvenajām raksturiezīmēm, pēt...

  17. Ru nanostructure fabrication using an anodic aluminum oxide nanotemplate and highly conformal Ru atomic layer deposition.

    Science.gov (United States)

    Kim, Woo-Hee; Park, Sang-Joon; Son, Jong-Yeog; Kim, Hyungjun

    2008-01-30

    We fabricated metallic nanostructures directly on Si substrates through a hybrid nanoprocess combining atomic layer deposition (ALD) and a self-assembled anodic aluminum oxide (AAO) nanotemplate. ALD Ru films with Ru(DMPD)(EtCp) as a precursor and O(2) as a reactant exhibited high purity and low resistivity with negligible nucleation delay and low roughness. These good growth characteristics resulted in the excellent conformality for nanometer-scale vias and trenches. Additionally, AAO nanotemplates were fabricated directly on Si and Ti/Si substrates through a multiple anodization process. AAO nanotemplates with various hole sizes (30-100 nm) and aspect ratios (2:1-20:1) were fabricated by controlling the anodizing process parameters. The barrier layers between AAO nanotemplates and Si substrates were completely removed by reactive ion etching (RIE) using BCl(3) plasma. By combining the ALD Ru and the AAO nanotemplate, Ru nanostructures with controllable sizes and shapes were prepared on Si and Ti/Si substrates. The Ru nanowire array devices as a platform for sensor devices exhibited befitting properties of good ohmic contact and high surface/volume ratio.

  18. Laser Spectroscopy of Ruthenium Containing Diatomic Molecules: RuH/D and RuP.

    Science.gov (United States)

    Adam, Allan G.; Konder, Ricarda M.; Nickerson, Nicole M.; Linton, Colan; Tokaryk, D. W.

    2015-06-01

    In the last few years, the Cheung group in Hong Kong and the Steimle group in Arizona have successfully studied several ruthenium containing diatomic molecules, RuX (X =C, O, N, B, using the laser-ablation molecular jet technique. Based on this success, the UNB spectroscopy group decided to try and find the optical signatures of other RuX molecules. Using CH_3OH and PH_3 as reactant gases, the RuH and RuP diatomic molecules have been detected in surveys of the 420 - 675 nm spectral region. RuD has also been made using fully deuterated methanol as a reactant. Dispersed fluorescence experiments have been performed to determine ground state vibrational frequencies and the presence of any low-lying electronic states. Rotationally resolved spectra for these molecules have also been taken and the analysis is proceeding. The most recent results will be presented. F. Wang et al., Journal of Chemical Physics 139, 174318 (2013). N. Wang et al., Journal of Physical Chemistry A 117, 13279 (2013). T. Steimle et al., Journal of Chemical Physics 119, 12965 (2003). N. Wang et al., Chemical Physics Letters 547, 21 (2012).

  19. Mifepristone (RU 486) treatment of meningiomas.

    OpenAIRE

    Lamberts, S.W.; Tanghe, H L; Avezaat, C J; Braakman, R; Wijngaarde, R.; Koper, J. W.; de Jong, H

    1992-01-01

    Meningiomas are common brain tumours which are generally benign, well circumscribed and slow growing. In a minority of patients complete surgical removal is not possible and re-growth of tumour tissue is a major clinical problem. Most meningiomas contain progesterone receptors. The anti-progestational drug mifepristone (RU 486) binds to these receptors. Ten patients were treated with 12 recurrent or primary "inoperable" meningiomas, all of whom had shown recent neuroradiological and/or ophtha...

  20. Hydrogen bonding and proton transfer to ruthenium hydride complex CpRuH(dppe): metal and hydride dichotomy.

    Science.gov (United States)

    Silantyev, Gleb A; Filippov, Oleg A; Tolstoy, Peter M; Belkova, Natalia V; Epstein, Lina M; Weisz, Klaus; Shubina, Elena S

    2013-02-18

    The combination of variable temperature (190-297 K) IR and NMR spectroscopy studies with quantum-chemical calculations at the DFT/B3PW91 and AIM level had the aim to determine the mechanism of proton transfer to CpRuH(dppe) (1, dppe = Ph(2)P(CH(2))(2)PPh(2)) and the structures of intermediates. Dihydrogen bond (DHB) formation was established in the case of interaction with weak proton donors like CF(3)CH(2)OH. Low-temperature protonation (at about 200 K) by stronger proton donors leads via DHB complex to the cationic nonclassical complex [CpRu(η(2)-H(2))(dppe)](+) (2). Thermodynamic parameters of DHB formation (for CF(3)CH(2)OH: ΔH°(HB) = -4.9 ± 0.2 kcal·mol(-1), ΔS°(HB) = -17.8 ± 0.7 cal·mol(-1)·K(-1)) and proton transfer (for (CF(3))(2)CHOH: ΔH°(PT) = -5.2 ± 0.3 kcal·mol(-1), ΔS°(PT) = -23 ± 1 cal·mol(-1)·K(-1)) were determined. Above 240 K 2 transforms into trans-[CpRu(H)(2)(dppe)](+) (3) yielding a mixture of 2 and 3 in 1:2 ratio. Kinetic analysis and activation parameters for the "[Ru(η(2)-H(2))](+) → trans-[Ru(H)(2)](+)" transformation indicate reversibility of this process in contrast to irreversible intramolecular isomerization of the Cp* analogue. Calculations show that the driving force of this process is greater stability (by 1.5 kcal·mol(-1) in ΔE scale) of the dihydride cation in comparison with the dihydrogen complex. The calculations of the potential energy profile indicate the low barrier for deprotonation of 2 suggesting that the formation of trans-[CpRu(H)(2)(dppe)](+) proceeds via deprotonation of [Ru(η(2)-H(2))](+) to DHB complex, formation of hydrogen bond with Ru atom and subsequent proton transfer to the metal site.

  1. Pt Ru/C electrocatalysts prepared using electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Oliveira Neto, Almir; Pino, Eddy S.; Brandalise, Michele; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: dfsilva@ipen.br; espinace@ipen.br

    2007-07-01

    Pt Ru/C electrocatalysts (carbon-supported Pt Ru nanoparticles) were prepared submitting water/ethylene glycol solutions containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The water/ethylene glycol ratio (v/v) was evaluated as synthesis parameters. The Pt Ru/C electrocatalysts were prepared with a nominal Pt:Ru atomic ratio of 50:50 and were characterized by energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) and tested for methanol electro-oxidation using cyclic voltammetry and chronoamperometry. The obtained Pt Ru/C electrocatalysts showed the typical fcc structure of platinum-ruthenium alloys and the electrocatalytic activity depends on the water/ethylene glycol ratio used in the preparation.

  2. Direct observation of the microstructure in cluster glass compound U{sub 2}IrSi{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Yubuta, K [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Yamamura, T [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Shiokawa, Y [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan)

    2006-07-05

    We have examined the structure of a U{sub 2}IrSi{sub 3} compound exhibiting ferromagnetic cluster glass behaviour by means of electron diffraction observation and high-resolution electron microscopy. The structure of U{sub 2}IrSi{sub 3} has been proposed as a new one of the U{sub 2}RuSi{sub 3}-type with a short-range ordered double stacking sequence of the U{sub 2}RuSi{sub 3}-type structure along the c-axis, and long-range ordered atomic arrangements in the a-b plane. The calculated patterns reproduce the characteristic features of observed electron patterns well. The Fourier-filtered high-resolution image clearly exhibits a micro-domain structure, which is considered to relate directly to the origin of the observed cluster glass behaviour in U{sub 2}IrSi{sub 3}.

  3. Perpendicular magnetic tunnel junctions with a synthetic storage or reference layer: A new route towards Pt- and Pd-free junctions

    Science.gov (United States)

    Cuchet, Léa; Rodmacq, Bernard; Auffret, Stéphane; Sousa, Ricardo C.; Prejbeanu, Ioan L.; Dieny, Bernard

    2016-02-01

    We report here the development of Pt and Pd-free perpendicular magnetic tunnel junctions (p-MTJ) for STT-MRAM applications. We start by studying a p-MTJ consisting of a bottom synthetic Co/Pt reference layer and a synthetic FeCoB/Ru/FeCoB storage layer covered with an MgO layer. We first investigate the evolution of RKKY coupling with Ru spacer thickness in such a storage layer. The coupling becomes antiferromagnetic above 0.5 nm and its strength decreases monotonously with increasing Ru thickness. This contrasts with the behavior of Co-based systems for which a maximum in interlayer coupling is generally observed around 0.8 nm. A thin Ta insertion below the Ru spacer considerably decreases the coupling energy, without basically changing its variation with Ru thickness. After optimization of the non-magnetic and magnetic layer thicknesses, it appears that such a FeCoB/Ru/FeCoB synthetic storage layer sandwiched between MgO barriers can be made stable enough to actually be used as hard reference layer in single or double magnetic tunnel junctions, the storage layer being now a single soft FeCoB layer. Finally, we realize Pt- or Pd-free robust perpendicular magnetic tunnel junctions, still keeping the advantage of a synthetic reference layer in terms of reduction of stray fields at small pillar sizes.

  4. Ruthenium redox equilibria 1. Thermodynamic stability of Ru(III) and Ru(IV) hydroxides

    OpenAIRE

    Igor Povar; Oxana Spinu

    2016-01-01

    On the basis of the selected thermodynamic data for Ru(III) and Ru(IV) compounds in addition to original thermodynamic and graphical approach used in this paper, the thermodynamic stability areas of sparingly soluble hydroxides as well as the repartition of their soluble and insoluble chemical species towards the solution pH and initial concentrations of ruthenium in heterogeneous mixture solid phase–saturated solution have been investigated. By means of the ΔG–pH diagrams, the areas of therm...

  5. Sideward flow of $K^{+}$ mesons in Ru+Ru and Ni+Ni reactions near threshold

    CERN Document Server

    Crochet, Philippe; Wisniewski, K; Leifels, Y; Andronic, A; Averbeck, R; Devismes, A; Finck, C; Gobbi, A; Hartmann, O; Hildenbrand, K D; Koczón, P; Kress, T; Kutsche, R; Reisdorf, W; Schull, D; Alard, J P; Barret, V; Basrak, Z; Bastid, N; Belyaev, I; Bendarag, A; Berek, G; Caplar, R; Cindro, N; Dupieux, P; Dzelalija, M; Eskef, M; Fodor, Z; Grishkin, Yu L; Hong, B; Kecskeméti, J; Kim, Y J; Kirejczyk, M; Korolija, M; Kotte, R; Kowalczyk, M; Lebedev, A; Lee, K S; Man'ko, V I; Merlitz, H; Mohren, S; Moisa, D; Neubert, W; Nyanin, A; Pelte, D; Petrovici, M; Plettner, C; Rami, F; De Schauenburg, B; Seres, Z; Sikora, B; Sim, K S; Simion, V; Siwek-Wilczynska, K; Smolyankin, V T; Somov, A; Stockmeier, M R; Stoicea, G; Vasilev, M A; Wagner, P; Wohlfarth, D; Yang, J T; Yushmanov, I E; Zhilin, A V

    2000-01-01

    Experimental data on K+ meson and proton sideward flow measured with the FOPI detector at SIS/GSI in the reactions Ru+Ru at 1.69 AGeV and Ni+Ni at 1.93 AGeV are presented. The K+ sideward flow is found to be anti-correlated (correlated) with the one of protons at low (high) transverse momenta. When compared to the predictions of a transport model, the data favour the existence of an in-medium repulsive K+ nucleon potential.

  6. Lanthanum-Promoted Ru/Sepiolite in Ammonia Synthesis

    Institute of Scientific and Technical Information of China (English)

    Le Zhiping; Lin Jianxin; Yu Xiujin; Huang Yueyu; Wei Kemei

    2005-01-01

    A new kind of Ru supported on sepiolite catalyst with La as promoter for ammonia synthesis was prepared. The effects of reaction conditions on catalytic activity were discussed. The result shows that La is an effective promoter for sepiolite-supported Ru based catalyst. When the load of Ru is 5% (mass fraction), and the molar ratio of La/Ru is 1.5, under the condition of 10 MPa 450 ℃ 20000 h-1, the ammonia synthesis rate is 38.5 mmol NH3·g-1·h-1.

  7. NBS karavīru motivācija dienēt Hercberga duālo faktoru motivācijas teorijas skatījumā

    OpenAIRE

    Andrijausks, Arvīds

    2012-01-01

    Šī darba galvenais uzdevums ir apskatīt Latvijas NBS karavīru motīvus dienēt un interpretēt to caur Frederika Hecberga „duālo faktoru” teoriju. Karavīru motivācija un motivāciju galvenie ietekmējošie faktori tiek noskaidroti ar daļēji strukturēto interviju un ranga tabulas (kuras vienības ir ņemtas no 2007.gada „NBS karavīru dienesta motivācijas analīze un komplektēšanas ar personālu stratēģijas izstrāde” armijas projekta) palīdzību. Darbā tiek apskatīts motivācijas jēdziens, tā skaidrojums, ...

  8. The PD-1/PD-Ls pathway and autoimmune diseases.

    Science.gov (United States)

    Dai, Suya; Jia, Ru; Zhang, Xiao; Fang, Qiwen; Huang, Lijuan

    2014-07-01

    The programmed death (PD)-1/PD-1 ligands (PD-Ls) pathway, is a new member of the B7/CD28 family, and consists of the PD-1 receptor and its ligands PD-L1 (B7-H1, CD274) and PD-L2 (B7-DC, CD273). Recently, it is reported that PD-1, PD-L1 and PD-L2 also have soluble forms aside from their membrane bound forms. The soluble forms increase the diversity and complexity of PD-1/PD-Ls pathway in both composition and function. The PD-1/PD-Ls pathway is broadly expressed and exerts a wider range of immunoregulatory roles in T-cell activation and tolerance compared with other B7/CD28 family members. Studies show that the PD-1/PD-Ls pathway regulates the induction and maintenance of peripheral tolerance and protects tissues from autoimmune attack in physiological conditions. In addition, it is also involved in various diseases mediated by T cells, such as autoimmunity, tumor immunity, chronic viral infections, and transplantation immunity. In this review, we will summarize the relevance of the soluble forms and the latest researches on the role of PD-1/PD-Ls pathway in autoimmune diseases.

  9. Carbon nanotubes-Nafion composites as Pt-Ru catalyst support for methanol electro-oxidation in acid media

    Institute of Scientific and Technical Information of China (English)

    Shengzhou Chen; Fei Ye; Weiming Lin

    2009-01-01

    Carbon nanotubes-Nafion (CNTs-Nafion) composites were prepared by impregnated CNTs with Nafion in ethanol solution and characterized by FT-IR. Pt-Ru catalysts supported on CNTs-Nafion composites were synthesized by microwave-assisted polyol process. The physical and electrochemical properties of the catalysts were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), CO stripping voltammetry, cyclic voltammetry (CV) and chronoamperometry (CA). The results showed that the Nafion incorporation in CNTs-Nafion composites did not significantly alter the oxygen-containing groups on the CNTs surface. The Pt-Ru catalyst supported on CNTs-Nafion composites with 2 wt% Nafion showed good dispersion and the best CO oxidation and methanol electro-oxidation activities.

  10. Isomeric [RuCl2(dmso)2(indazole)2] complexes: ruthenium(II)-mediated coupling reaction of acetonitrile with 1H-indazole.

    Science.gov (United States)

    Reisner, Erwin; Arion, Vladimir B; Rufińska, Anna; Chiorescu, Ion; Schmid, Wolfgang F; Keppler, Bernhard K

    2005-07-21

    Reaction of the antitumor complex trans-[Ru(III)Cl4(Hind)2]- (Hind = indazole) with an excess of dimethyl sulfoxide (dmso) in acetone afforded the complex trans,trans,trans-[Ru(II)Cl2(dmso)2(Hind)2] (1). Two other isomeric compounds trans,cis,cis-[Ru(II)Cl2(dmso)2(Hind)2] (2) and cis,cis,cis-[Ru(II)Cl2(dmso)2(Hind)2] (3) have been obtained on refluxing cis-[Ru(II)Cl(2)(dmso)(4)] with 2 equiv. of indazole in ethanol and methanol, respectively. Isomers 1 and 2 react with acetonitrile yielding the complexes trans-[Ru(II)Cl2(dmso)(Hind){HN=C(Me)ind}].CH3CN (4.CH3CN) and trans,cis-[Ru(II)Cl2(dmso)2{HN=C(Me)ind}].H2O (5.H2O), respectively, containing a cyclic amidine ligand resulting from insertion of the acetonitrile C triple bond N group in the N1-H bond of the N2-coordinated indazole ligand in the nomenclature used for 1H-indazole. These are the first examples of the metal-assisted iminoacylation of indazole. The products isolated have been characterized by elemental analysis, IR spectroscopy, UV-vis spectroscopy, electrospray mass-spectrometry, thermogravimetry, differential scanning calorimetry, 1H NMR spectroscopy, and solid-state 13C CP MAS NMR spectroscopy. The isomeric structures of 1-3 and the presence of a chelating amidine ligand in 4 and 5 have been confirmed by X-ray crystallography. The electrochemical behavior of 1-5 and the formation of 5 have been studied by cyclic voltammetry.

  11. Structure, synthesis, and thermal properties of trans-[Ru(NO)(NH{sub 3}){sub 4}(SO{sub 4})]NO{sub 3}.H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Makhinya, A.N.; Il' in, M.A.; Plyusnin, P.E. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Nikolaev Inst. of Inorganic Chemistry; Novosibirsk State Univ. (Russian Federation); Baidina, I.A.; Alferova, N.I.; Pishchur, D.P. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Nikolaev Inst. of Inorganic Chemistry

    2014-07-01

    In treatment of trans-[Ru(NO)(NH{sub 3}){sub 4}(OH)]Cl{sub 2} with concentrated sulfuric acid on heating trans-[Ru(NO)(NH{sub 3}){sub 4}(SO{sub 4})](HSO{sub 4}).H{sub 2}O (I) is obtained with a yield close to quantitative. In the interaction of the saturated solution of I with a saturated NaNO{sub 3} solution a trans-[Ru(NO)(NH{sub 3}){sub 4}(SO{sub 4})]NO{sub 3}.H{sub 2}O (II) precipitate forms whose structure is determined by single crystal XRD: space group P2{sub 1}2{sub 1}2{sub 1}, a = 6.8406(3) Aa, b = 12.6581(5) Aa, c = 13.3291(5) Aa. A monodentately coordinated sulfate ion is in the trans-position to the nitroso group. Compound II is characterized by IR spectroscopy, powder XRD, and diffuse reflectance spectroscopy. The process of its thermolysis is studied; by differential scanning calorimetry the thermal effect of the dehydration reaction occurring on heating to 120 C (ΔH = 58.9 ± 1.5 kJ/mol) is estimated. The final product of the thermolysis of II is a mixture of Ru and RuO{sub 2}.

  12. $\\it{Ab-initio}$ calculations of electric field gradient in Ru compounds and their implication on the nuclear quadrupole moments of $^{99}$Ru and $^{101}$Ru

    Indian Academy of Sciences (India)

    S N MISHRA

    2017-08-01

    The nuclear quadrupole moments, $\\mathcal{Q}$, for the ground and first excited states in $^{99}$Ru and ground state of $^{101}$Ru have been determined by comparing the experimentally observed quadrupole interaction frequencies $\\mathcal{ν_{Q}}$ with calculated electric field gradient (EFG) for a large number of Ru-based compounds. The $\\it{ab-initio}$ calculations of EFG were performed using the all-electron augmented plane wave + local orbital (APW + lo) method of the density functional theory (DFT). From the slope of the linear correlation between theoretically calculated EFGs and experimentally observed $\\mathcal{ν_{Q}}$, we obtain the quadrupole moment for the $(5/2^{+})$ ground state in $^{99}$Ru and $^{101}$Ru as 0.0734(17) b and 0.431(14) b respectively, showing excellent agreement with the values reported in literature. For $3/2^{+}$, the quadrupole moment of the first excited state in $^{99}$Ru is obtained as +0.203(3) b, which is considerably lower than the commonly accepted literature value of +0.231(12) b. The results presented in this paper would be useful for the precise determination of quadrupole moment of high spin states in other Ru isotopes and is likely to stimulate further shell model calculations for an improved understanding of nuclear shape in these nuclei.

  13. Ab-initio calculations of electric field gradient in Ru compounds and their implication on the nuclear quadrupole moments of ^{99}Ru and ^{101}Ru

    Science.gov (United States)

    Mishra, S. N.

    2017-08-01

    The nuclear quadrupole moments, Q, for the ground and first excited states in ^{99}Ru and ground state of ^{101}Ru have been determined by comparing the experimentally observed quadrupole interaction frequencies ν _Q with calculated electric field gradient (EFG) for a large number of Ru-based compounds. The ab-initio calculations of EFG were performed using the all-electron augmented plane wave + local orbital (APW + lo) method of the density functional theory (DFT). From the slope of the linear correlation between theoretically calculated EFGs and experimentally observed ν _Q, we obtain the quadrupole moment for the (5/2^+) ground state in ^{99}Ru and ^{101}Ru as 0.0734(17) b and 0.431(14) b respectively, showing excellent agreement with the values reported in literature. For 3/2^+, the quadrupole moment of the first excited state in ^{99}Ru is obtained as +0.203(3) b, which is considerably lower than the commonly accepted literature value of +0.231(12) b. The results presented in this paper would be useful for the precise determination of quadrupole moment of high spin states in other Ru isotopes and is likely to stimulate further shell model calculations for an improved understanding of nuclear shape in these nuclei.

  14. Hydrido thiolato and thiolato complexes of ruthenium(II) carbonyl phosphines. [cis,cis,trans-RuH(SR)(CO) sub 2 L sub 2 , cis,cis,trans-RuH(SR) sub 2 (CO) sub 2 L sub 2 where R = aryl and L = triphenylphosphine

    Energy Technology Data Exchange (ETDEWEB)

    Jessop, P.G.; Rettig, S.J.; Chungli Lee; James, B.R. (Univ. of British Columbia, Vancouver (Canada))

    1991-11-27

    Oxidative addition of RSH (R = H, alkyl, aryl) or RSSR (R = aryl) to Ru(CO){sub 2}L{sub 3} (L = PPh{sub 3}, 1) yields respectively cct-RuH(SR)(CO){sub 2L}{sub 2} (type 2) (cct = cis, cis, trans) or cct-Ru(SR){sub 2}(CO){sub 2}L{sub 2} (type 3); a hydrido selenolate species is made similarly using PhSeH. Methods for in situ formation of corresponding mixed bis(thiolate) species are also given. 1 is generally unreactive toward thioethers, although with propylene sulfide cct-Ru({eta}{sup 2}-S{sub 2}) (CO){sub 2}L{sub 2} is produced. Metathesis reaction of cct-RuCl{sub 2}(CO){sub 2}L{sub 2} with NaSR salts yield 3 (R = aryl) or, when R = Et, cct-RuCl(SEt)(CO){sub 2}L{sub 2} or (L(CO){sub 2}Ru({mu}{sub 3}-SEt)Na(THF)){sub 2} (4), depending on reaction conditions. The complexes are characterized by IR spectroscopy, {sup 1}H, {sup 31}P, and, in some cases, {sup 13}C NMR spectroscopy, and for 2g and 3g(R = SC{sub 6}H{sub 4}pMe) and 4, X-ray crystallography. All three complexes crystallized in the space group P {bar 1} 1. 4 has an unprecedented network of transition-metal and alkali-metal ions bridged by thiolate ligands: four thiolates bridge one Ru and one Na, and two thiolates bridge one Ru and two Na atoms. The geometries at Ru and Na are close to octahedral and square pyramidal respectively. Trends are noted for the {sup 1}H NMR shifts and {sup 2}J{sub PH} values for the hydride in 2, and an additivity rule formulated for the {sup 31}P shift within the cct-Ru(SR)(SR')(CO){sub 2}(PPh{sub 3}){sub 2} species. Limited kinetic data suggest that the oxidative addition reactions to 1 probably proceed via a nonradical process, following dissociation of a PPh{sub 3} ligand.

  15. Design, synthesis, DNA-binding affinity, cytotoxicity, apoptosis, and cell cycle arrest of Ru(II) polypyridyl complexes.

    Science.gov (United States)

    Venkat Reddy, Putta; Reddy, Mallepally Rajender; Avudoddi, Srishailam; Praveen Kumar, Yata; Nagamani, Chintakuntla; Deepika, Nancherla; Nagasuryaprasad, K; Singh, Surya Satyanarayana; Satyanarayana, Sirasani

    2015-09-15

    A novel polypyridyl ligand CNPFIP (CNPFIP=2-(5(4-chloro-2-nitrophenyl)furan-2-yl)-1H-imidazo[4,5f][1,10]phenanthroline) and its mononuclear Ru(II) polypyridyl complexes of [Ru(phen)2CNPFIP](2+)(1) (phen=1,10-phenanthroline), [Ru(bpy)2CNPFIP](2+)(2) (bpy=2,2'-bipyridine), and [Ru(dmb)2CNPFIP](2+)(3) (dmb=4,4'-dimethyl-2,2'-bipyridine) have been synthesized successfully and characterized thoroughly by elemental analysis, UV/Vis, IR, NMR, and ESI-MS. The interaction of the Ru(II) complexes with calf thymus DNA (CT-DNA) was investigated by absorption titration, fluorescence, viscosity measurements. The experimental results suggest that three complexes bind to CT-DNA through an intercalative mode and the DNA-binding affinity of complex 1 is greater than that of complexes 2 and 3. The photocleavage of plasmid pBR322 DNA by ruthenium complexes 1, 2, and 3 was investigated. We have also tested three complexes for their antimicrobial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. The in vitro cytotoxicity of these complexes was evaluated by MTT assay, and complex 1 shows higher cytotoxicity than 2 and 3 on HeLa cells. The induced apoptosis and cell cycle arrest of HeLa cells were investigated by flow cytometry for 24h. The molecular docking of ruthenium complexes 1, 2, and 3 with the active site pocket residues of human DNA TOP1 was performed using LibDock.

  16. Antibacterial activity of Pd(II) complexes with salicylaldehyde-amino acids Schiff bases ligands.

    Science.gov (United States)

    Rîmbu, Cristina; Danac, Ramona; Pui, Aurel

    2014-01-01

    Palladium(II) complexes with Schiff bases ligands derived from salicylaldehyde and amino acids (Ala, Gly, Met, Ser, Val) have been synthesized and characterized by Fourier transform (FT)-IR, UV-Vis and (1)H-NMR spectroscopy. The electrospray mass spectrometry (ES-MS) spectrometry confirms the formation of palladium(II) complexes in 1/2 (M/L) molar ratio. All the Pd(II) complexes 1, [Pd(SalAla)2]Cl2; 2, [Pd(SalGly)2]Cl2; 3, [Pd(SalMet)2]Cl2; 4, [Pd(SalSer)2]Cl2; 5, [Pd(SalVal)2]Cl2; have shown antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

  17. HWIL IR imaging testing

    Science.gov (United States)

    Vinson, R. J.; Passwater, R. D.

    1981-03-01

    The Army simulator facilities are presently configured to conduct hardware-in-the-loop mission tasks on the HELLFIRE and COPPERHEAD missile systems. These systems presently use a LASER seeker. The facility is an ideal candidate to be converted to include infrared (IR) seekers used on the TGSM system. This study investigates the possibility and impact of a facility update. This report documents the feasibility of developing a hardware-in-the-loop (HWIL) hybrid simulation incorporating infrared IR seekers used for the Assault Breaker program. Other hardware to be considered are the autopilot, signal conditioning, signal processing, and actuators which may be integrated into the system simulation. Considerations are given to replacing all or elements of hardware while substituting math models in the system simulation.

  18. Study of the Pt/Ru(0001) Interface

    DEFF Research Database (Denmark)

    Godowski, Jan P; Li, Zhe Shen; Bork, Jakob

    2007-01-01

    The growth process of platinum on Ru(0001) near room temperature was characterized using photoelectron spectroscopy of high resolution. The binding energy position and intensity of the Pt 4f7/2 and Ru 3d5/2 core levels as well as the shape and structure of the valence band spectra corresponding t...

  19. Dramatic destabilization of the Ru(0001) surface upon oxygen adsorption

    Science.gov (United States)

    Reuter, K.; Ganduglia-Pirovano, M. V.; Scheffler, M.; Stampfl, C.

    2000-03-01

    Under high oxygen pressures, where most other transition metal surfaces typically form inert surface oxides, Ru(0001) displays the highest rates for oxidation reactions. This unusual behavior has been attributed to the fact that Ru can exist in different oxidation states and to the ease with which its surface can be loaded with high concentrations of subsurface oxygen. Yet, recent experiments have also indicated that high oxygen loads in the subsurface region destabilize Ru(0001) and lead to the emission of RuOx (xA. Böttcher, H. Conrad and H. Niehus, J. Chem. Phys. (submitted).). We perform density functional theory calculations to gain a fundamental understanding of the O-Ru bond in on-surface as well as subsurface oxygen phases. After completion of a full monolayer coverage on the surface, Ru(0001) is found to strongly bind even up to another full monolayer in the sites directly below the first substrate layer. In agreement with the experimental findings, this highly loaded O-Ru-O fringe is then relatively instable against lift-off, which might lead to either RuOx fragmentation or restructuring. The relation between charge transfer towards the oxygen and bond formation, as well as substrate destabilization is discussed.

  20. Electronic structure of Fe- vs. Ru-based dye molecules

    DEFF Research Database (Denmark)

    Johnson, Phillip S.; Cook, Peter L.; Zegkinoglou, Ioannis;

    2013-01-01

    In order to explore whether Ru can be replaced by inexpensive Fe in dye molecules for solar cells, the differences in the electronic structure of Fe- and Ru-based dyes are investigated by X-ray absorption spectroscopy and first-principles calculations. Molecules with the metal in a sixfold...

  1. Ru isotope heterogeneity in the solar protoplanetary disk

    Science.gov (United States)

    Fischer-Gödde, Mario; Burkhardt, Christoph; Kruijer, Thomas S.; Kleine, Thorsten

    2015-11-01

    Nucleosynthetic isotope anomalies in bulk chondrites and differentiated meteorites reflect variable proportions of isotopically diverse presolar components in bulk planetary bodies, but the origin of these heterogeneities is not well understood. Here, the Ru isotope composition of a comprehensive suite of iron meteorites and bulk samples of ordinary, enstatite and carbonaceous chondrites, as well as acid leachates and an insoluble residue of the Allende chondrite are examined using newly developed multi-collector inductively coupled plasma mass spectrometry techniques. Except for IAB iron meteorites and enstatite chondrites, all investigated meteorites show well-resolved Ru isotope anomalies. Of these, within-group Ru isotopic variations observed for samples from a given chemical group of iron meteorites reflect secondary neutron capture induced Ru isotope shifts during prolonged cosmic ray-exposure. After correction of these cosmogenic effects using Pt isotopes as a neutron-dose monitor, the remaining Ru isotope anomalies are nucleosynthetic in nature and are consistent with a deficit in s-process Ru in iron meteorite parent bodies. Similarly, Ru isotope anomalies in bulk ordinary and carbonaceous chondrites also reflect a deficiency in s-process Ru. The sequential dissolution of Allende reveals the presence of an HF-soluble s-process carrier, which is either an unidentified presolar phase or a component that incorporated s-process Ru liberated from SiC grains during nebular or parent body processes. We show that varying proportions of the s-process carrier identified in Allende resulted in the correlated Ru isotope anomalies observed for bulk meteorites, and that all meteorites (except possibly IAB irons and enstatite chondrites) are depleted in this s-process component relative to Ru from the Earth's mantle. Bulk meteorites exhibit correlated Ru and Mo isotope anomalies, reflecting variable deficits of a common s-process component, but some iron meteorites and

  2. Bifunctional electrocatalysis in pt-ru nanoparticle systems.

    Science.gov (United States)

    Roth, C; Benker, N; Theissmann, R; Nichols, R J; Schiffrin, D J

    2008-03-04

    Pt-Ru alloys are prominent electrocatalysts in fuel cell anodes as they feature a very high activity for the oxidation of reformate and methanol. The improved CO tolerance of these alloys has been discussed in relation to the so-called ligand and bifunctional mechanisms. Although these effects have been known for many years, they are still not completely understood. A new approach that bridges the gap between single crystals and practical catalysts is presented in this paper. Nanoparticulate model systems attached to an oxidized glassy carbon electrode were prepared by combining both ligand-stabilized and spontaneously deposited Pt and Ru nanoparticles. These electrodes showed very different voltammetric responses for CO and methanol oxidation. The cyclic voltammograms were deconvoluted into contributions attributed to Pt, Ru, and Pt-Ru contact regions to quantify the contribution of the latter to the bifunctional mechanism. Scanning transmission electron microscopy confirmed the proximity of Pt and Ru nanoparticles in the different samples.

  3. EFFECT OF MIFEPRISTONE (RU486) ON MARKERS OF ENDOMETRIAL RECEPTIVITY

    Institute of Scientific and Technical Information of China (English)

    武捷; 王龙生; 程捷; 王介东

    2003-01-01

    Objective To study the effect of single and low dose of RU486 on endometrial receptivity of healthy women. Methods A total of 5 healthy women were followed for one control and one treatment cycle. In the treatment cycle, a dose of 10 mg RU486 was administered on day luteinizing hormone (LH)-2. In both the control and treatment cycle, an endometrial biopsy was obtained on LH+7. These biopsies were assessed by immunohistochemical analysis to find the difference in expression of integrins and progesterone receptor (PR) between the control and treatment cycle. Results The treatment with RU486 increased the expression of α1 and α4 subunits of integrin in glandular epithelial cells, but did not influence β3 subunit. Moreover, the normal down-regulation of PR in epitherial cell nuclei was inhibited by 10 mg RU486. Conclusion Single dose of 10 mg RU486 impairs the establishment of endometrial receptivity on time.

  4. PtRu/C electrocatalysts prepared using {gamma}-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Neto, Almir Oliveira; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP, Av. Professor Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil)

    2007-07-10

    PtRu/C electrocatalysts (carbon-supported PtRu nanoparticles) were prepared submitting water/ethylene glycol solutions containing Pt(IV) and Ru(III) ions and the carbon support to {gamma}-irradiation. The water/ethylene glycol ratio (v/v) and the total dose (kGy) were evaluated as synthesis parameters. The electrocatalysts were characterized by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained PtRu/C electrocatalysts were more active for methanol electro-oxidation than the commercial PtRu/C electrocatalyst at ambient temperature and the electrocatalytic activity depends on the water/ethylene glycol ratio used in the preparation. (author)

  5. Localised IR spectroscopy of hemoglobin

    CERN Document Server

    Yarrow, Fiona

    2010-01-01

    IR absorption spectroscopy of hemoglobin was performed using an IR optical parametric oscillator laser and a commercial atomic force microscope in a novel experimental arrangement based on the use of a bottom-up excitation alignment. This experimental approach enables detection of protein samples with a resolution that is much higher than that of standard IR spectroscopy. Presented here are AFM based IR absorption spectra of micron sized hemoglobin features

  6. IR nanoscale spectroscopy and imaging

    Science.gov (United States)

    Kennedy, Eamonn; Yarrow, Fiona; Rice, James H.

    2011-10-01

    Sub diffraction limited infrared absorption imaging was applied to hemoglobin by coupling IR optics with an atomic force microscope. Comparisons between the AFM topography and IR absorption images of micron sized hemoglobin features are presented, along with nanoscale IR spectroscopic analysis of the metalloprotein.

  7. Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts for the alkaline direct ethanol fuel cell (DEFC)

    CSIR Research Space (South Africa)

    Modibedi, M

    2011-09-01

    Full Text Available gas. On the other hand, the commercialization of DAFCs is limited by the slow electro-kinetics of alcohol oxidation and alcohol crossover through the membrane to the cathode side. The kinetics of alcohol oxidation and oxygen reduction reactions can...

  8. Fischer–Tropsch Synthesis: Effect of Reducing Agent for Aqueous-Phase Synthesis Over Ru Nanoparticle and Supported Ru Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Pendyala, Venkat Ramana Rao [Univ. of Kentucky, Lexington, KY (United States); Shafer, Wilson D. [Univ. of Kentucky, Lexington, KY (United States); Jacobs, Gary [Univ. of Kentucky, Lexington, KY (United States); Graham, Uschi M. [Univ. of Kentucky, Lexington, KY (United States); Khalid, Syed [Brookhaven National Lab. (BNL), Upton, NY (United States); Davis, Burtron H. [Univ. of Kentucky, Lexington, KY (United States)

    2014-12-27

    The effect of the reducing agent on the performance of a ruthenium nanoparticle catalyst was investigated during aqueous-phase Fischer–Tropsch synthesis using a 1 L stirred tank reactor in the batch mode of operation. For the purpose of comparison, the activity and selectivity of NaY zeolite supported Ru catalyst were also studied. NaBH4 and hydrogen were used as reducing agents in our study, and hydrogen reduced catalysts exhibited higher activities than the NaBH4 reduced catalysts, because of higher extent of reduction and a relatively lower tendency toward agglomeration of Ru particles. The Ru nanoparticle catalyst displayed higher activities than the NaY zeolite supported Ru catalyst for both reducing agents. NaBH4 reduced catalysts are less active and the carbon dioxide selectivity is higher than the hydrogen reduced catalysts. The activity of the supported Ru catalyst (Ru/NaY) was 75 % of that of the Ru nanoparticle catalyst, and has the benefit of easy wax/catalyst slurry separation by filtration. Finally, the hydrogen reduced supported Ru catalyst exhibited superior selectivity towards hydrocarbons (higher C5+ selectivity and lower selectivity to methane) than all other catalysts tested.

  9. Albuminas ir jo vartojimas

    OpenAIRE

    Reingardienė, Dagmara Ona

    2002-01-01

    Albuminas yra natūralus koloidas, tačiau jo vartojimo svarba ir efektyvumas, gydant kritines būkles, pastaraisiais metais iš esmės pasikeitė. Šiame straipsnyje aptariami naujausi literatūros duomenys apie albumino vartojimą. Aišku, kad įprastas albumino vartojimas, esant sumažėjusiam jo kiekiui plazmoje, nerekomenduotinas. Šiuo metu moksliškai pagrįstų indikacijų albumino vartojimui nėra. Jo galima skirti tik kaip antrojo pasirinkimo tirpalą tais atvejais, kai kiti tirpalai neindikuotini ar k...

  10. IR and the Earth

    DEFF Research Database (Denmark)

    Corry, Olaf; Stevenson, Hayley

    2017-01-01

    , in the end, one finite interconnected space. Together these two starting points make for the basic conundrum of Inter- national Relations and the Earth: how does a divided world live on a single globe? This introduction first provides an overview of the recent rise of ‘the environment’ in international......, ‘what has the environment ever done for IR?’, before the plan for the rest of the book sketches the content and direction of the ensuing chapters that explore the problematique of International Relations and the Earth....

  11. The IRS-1 signaling system.

    Science.gov (United States)

    White, M F

    1994-02-01

    IRS-1 is a principal substrate of the insulin receptor tyrosine kinase. It undergoes multi-site tyrosine phosphorylation and mediates the insulin signal by associating with various signaling molecules containing Src homology 2 domains. Interleukin-4 also stimulates IRS-1 phosphorylation, and it is suspected that a few more growth factors or cytokines will be added to form a select group of receptors that utilize the IRS-1 signaling pathway. More IRS-1-like adapter molecules, such as 4PS (IRS-2), may remain to be found.

  12. [(p-Cymene)RuCl2 ]2 : an efficient catalyst for highly regioselective allylic alkylations of chelated amino acid ester enolates.

    Science.gov (United States)

    Bayer, Anton; Kazmaier, Uli

    2014-08-11

    Chelated amino acid ester enolates are excellent nucleophiles for ruthenium-catalyzed allylic alkylations. Although [Cp*Ru(MeCN)3 ]PF6 was found to be the most reactive catalyst investigated, with the resulting allyl complexes reacting at temperatures as low as -78 °C, unfortunately the process took place with only moderate regio- and diastereoselectivity. In contrast, [(p-cymene)RuCl2 ]2 allowed allylations to be performed with a high degree of regioretention. Secondary allyl carboxylates with a terminal double bond were found to be the most reactive substrates, giving rise to the branched amino acids with perfect regioretention and chirality transfer. In this case, no isomerization of the Ru-allyl complex formed in situ was observed, in contrast to the analogues palladium complexes. This isomerization-free protocol can also be used for the synthesis of (Z)-configured γ,δ-unsaturated amino acid derivatives, starting from (Z)-allylic substrates. Here, the more reactive phosphates were found to be superior to the carboxylates, providing the required amino acids in almost quantitative yield with perfect regio- and stereoretention. Therefore, the Ru-catalyzed allylation reactions are well positioned to overcome the drawbacks of Pd-catalyzed processes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Microwave-assisted synthesis of arene Ru(Ⅱ) complex [(η6-C6H5) Ru(PIP) Cl]Cl·2H2O%微波辅助合成芳烃钌(Ⅱ)配合物[(η6-C6H5)Ru(PIP)Cl]Cl·2H2O

    Institute of Scientific and Technical Information of China (English)

    陈艾纯; 吴琼; 陈燕华; 梅文杰; 吴韦黎; 胡晓莹; 吴剑; 汪保国

    2013-01-01

    目的 探讨应用微波辅助合成技术制备芳烃钌(Ⅱ)化合物[(η6-C6H6)Ru(PIP) Cl] Cl·2H2O(3).方法 首先以RuCl3·nH2O、1,3-环己二烯和1,10-邻菲哕啉为原料微波辐射下制备得到芳烃钌前体[(η6-C6H6)RuCl2]2(1)和2-苯基-咪唑并[4,5f][1,10]菲哕啉(PIP,2),然后,在二氯甲烷溶液中,微波辐射1与2制备芳烃钌(Ⅱ)配合物3;采用ESI-MS、IR、1H-NMR、13C-NMR对目标配合物进行表征.结果 60℃条件下,化合物1与2在二氯甲烷溶液微波辐射30 min,制备得到了芳烃钌配合物3,反应产率为90.3%;目标产物经ESI-MS、IR、1H-NMR和13C-NMR表征,实验值与理论值基本一致.结论 与传统加热方法相比,微波辅助合成芳烃钌配合物明显缩短了反应时间,提高了反应产率.%Objective To research the preparation of arene Ru( Ⅱ ) complex [η6-C6H6)RU(PIP)Cl]Cl· 2H2O(3) by using microwave-assisted synthesis technology. Methods [ ( η6 -C6H6 ) RuCl2 ]2 (1) was synthesized from RuCl2 · nH2O and 1,3-cyclohexadiene by using microwave-assisted synthesis technology, and 2-phenyl-imidazole[4,5/] [1,10]phenanthroline (PIP,2) also synthesized from 1,10-phenanthroline-5 ,6-dione and benzaldehyde under microwave irradiation, and then 2 and 3 were mixed in CH2Cl2 solution to prepare [ (η6-C6H6)Ru( PIP) Cl] Cl · 2H2O (3) under the irradiation microwave. The target complex 3 was characterized by using ESI-MS, IR,1H-NMR and 13C-NMR spectra. Results Arene Ru( Ⅱ ) complex 3 was prepared from 1 and 2 in CH2Cl2 at 60℃ for 30 min under microwave irradiation with a yield of 90. 3%,and characterized by ESI-MS, IR,1H-NMR and 13C-NMR spectra. Conclusion A novel arene ruthenium ( Ⅱ ) complexes 3 have been synthesized under the irradiation of microwave, and with far more less time and higher yield compared with the conventional method.

  14. Hydrothermal synthesis of highly crystalline RuS{sub 2} nanoparticles as cathodic catalysts in the methanol fuel cell and hydrochloric acid electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yanjuan [Key Laboratory of Marine Chemistry Theory and Technology, Minisry of Education Ocean University of China, Qingdao, 266100 (China); College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Li, Nan, E-mail: lin@jlu.edu.cn [College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Yanagisawa, Kazumichi [Research Laboratory of Hydrothermal Chemistry, Kochi University, Kochi 780-8520 (Japan); Li, Xiaotian [College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Yan, Xiao [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China)

    2015-05-15

    Highlights: • Highly crystalline RuS{sub 2} nanoparticles have been first synthesized by a “one-step” hydrothermal method. • The product presents a pure cubic phase of stoichiometric ratio RuS{sub 2} with average particle size of 14.8 nm. • RuS{sub 2} nanoparticles were used as cathodic catalysts in methanol fuel cell and hydrochloric acid electrolysis. • The catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl{sup −}. - Abstract: Highly crystalline ruthenium sulfide (RuS{sub 2}) nanoparticles have been first synthesized by a “one-step” hydrothermal method at 400 °C, using ruthenium chloride and thiourea as reactants. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy/energy disperse spectroscopy (SEM/EDS), thermo gravimetric-differential thermal analyze (TG-DTA), transmission electron microscopy equipped with selected area electron diffraction (TEM/SAED). Fourier transform infrared spectra (IR), and X-ray photoelectron spectroscopy (XPS). XRD result illustrates that the highly crystalline product presents a pure cubic phase of stoichiometric ratio RuS{sub 2} and the average particle size is 14.8 nm. SEM and TEM images display the products have irregular shape of 6–25 nm. XPS analyst indicates that the sulfur exists in the form of S{sub 2}{sup 2−}. Cyclic voltammetry (CV), rotating disk electrode (RDE), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements are conducted to evaluate the electrocatalytic activity and stability of the highly crystalline RuS{sub 2} nanoparticles in oxygen reduction reaction (ORR) for methanol fuel cell and hydrochloric acid electrolysis. The results illustrate that RuS{sub 2} is active towards oxygen reduction reaction. Although the activity of RuS{sub 2} is lower than that of Pt/C, the RuS{sub 2} catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl{sup −}.

  15. Detailed IR aperture measurements

    CERN Document Server

    Bruce, Roderik; Garcia Morales, Hector; Giovannozzi, Massimo; Hermes, Pascal Dominik; Mirarchi, Daniele; Quaranta, Elena; Redaelli, Stefano; Rossi, Carlo; Skowronski, Piotr Krzysztof; Wretborn, Sven Joel; CERN. Geneva. ATS Department

    2016-01-01

    MD 1673 was carried out on October 5 2016, in order to investigate in more detail the available aperture in the LHC high-luminosity insertions at 6.5 TeV and β∗=40 cm. Previous aperture measurements in 2016 during commissioning had shown that the available aperture is at the edge of protection, and that the aperture bottleneck at β∗=40 cm in certain cases is found in the separation plane instead of in the crossing plane. Furthermore, the bottlenecks were consistently found in close to the upstream end of Q3 on the side of the incoming beam, and not in Q2 on the outgoing beam as expected from calculations. Therefore, this MD aimed at measuring IR1 and IR5 separately (at 6.5 TeV and β∗=40 cm, for 185 µrad half crossing angle), to further localize the bottlenecks longitudinally using newly installed BLMs, investigate the difference in aperture between Q2 and Q3, and to see if any aperture can be gained using special orbit bumps.

  16. Compatibility of RuO2 electrodes with PZT ceramics

    Indian Academy of Sciences (India)

    K T Jacob; G Rajitha; V S Saji

    2009-06-01

    Because of its high electrical conductivity and good diffusion barrier properties ruthenium dioxide (RuO2) is a good electrode material for use with ferroelectric lead zirconate–titanate (PZT) solid solutions. Under certain conditions, RuO2 can react with PZT to form lead ruthenate (Pb2Ru2O6.5) during processing at elevated temperatures resulting in lead depletion from PZT. The standard Gibbs energies of formation of RuO2 and Pb2Ru2O6.5 and activities of components of the PZT solid solution have been determined recently. Using this data along with older thermodynamic information on PbZrO3 and PbTiO3, the stability domain of Pb2Ru2O6.5 is computed as a function of PZT composition, temperature and oxygen partial pressure in the gas phase. The results show PbZrO3-rich compositions are more prone to react with RuO2 at all temperatures. Increasing temperature and decreasing oxygen partial pressure suppress the reaction. Graphically displayed are the reaction zones as a function of oxygen partial pressure and PZT composition at temperatures 973, 1173 and 1373 K.

  17. Fast selective metal deposition on polymers by using IR and excimer VUV photons

    Science.gov (United States)

    Esrom, Hilmar

    2000-12-01

    The major advantages of infra-red (IR) lamp induced decomposition of metal organic films for large-area deposition of metal films on substrate surfaces, local excimer laser ablation of thin metal films, and subsequent electroless metal plating were combined to develop a novel fast selective metallisation technique for thermally stable polymers. With the new method, metal structures with high edge quality on different types of polyimide (PI) foils can be produced easily. Without damaging the underlying PI substrate, the metal organic film (e.g. palladium acetate, PdAc) can be decomposed by infra-red irradiation in only about one second. The precise etching capability of ArF excimer laser ablation at λ=193 nm allows the IR-induced palladium (Pd) layers to be removed from the PI surface with one excimer laser pulse, selectively. The residual patterned Pd film on the PI surface then acts as an excellent catalyst for conventional electroless copper plating.

  18. Fabrication of metal nanoclusters on graphene grown on Ru(0001)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; FU Qiang; CUI Yi; TAN DaLi; BAO XinHe

    2009-01-01

    Monolayer graphene was epitaxially grown on Ru(0001) through exposure of the Ru(0001) to ethylene at room temperature followed by annealing in ultrahigh vacuum at elevated temperatures. The resulting graphene structures were studied by scanning tunneling microscopy (STM), X-ray photoelectron spec-troscopy (XPS), and ultraviolet photoelectron spectroscopy (UPS). The graphene/Ru(0001) surface was used as a periodic template for growth of metal nanoclusters. Highly dispersed Pt clusters with well controlled size and spatial distribution were fabricated on the surface.

  19. Light Activation of a Cysteine Protease Inhibitor: Caging of a Peptidomimetic Nitrile with RuII(bpy)2

    Science.gov (United States)

    Respondek, Tomasz; Garner, Robert N.; Herroon, Mackenzie K.; Podgorski, Izabela; Turro, Claudia; Kodanko, Jeremy J.

    2013-01-01

    A novel method for caging protease inhibitors is described. The complex [RuII(bpy)2(1)2](PF6)2 (2) was prepared from the nitrile-based peptidomimetic inhibitor Ac-Phe-NHCH2CN (1). 1H NMR, UV-vis and IR spectroscopic and mass spectrometric data confirm that two equiv of inhibitor 1 bind to RuII through the nitrile functional group. Complex 2 shows excellent stability in aqueous solution in the dark and fast release of 1 upon irradiation with visible light. Due to binding to the RuII center, the nitriles of complex 2 are caged, and 2 does not act as a potent enzyme inhibitor. However, when 2 is irradiated, it releases 1 that inhibits the cysteine proteases papain and cathepsins B, K and L, up to two times more potently than 1 alone. Ratios for IC50 values for 2 range from 6:1 to 33:1 under dark vs. light conditions, against isolated enzymes and in human cell lysates, confirming a high level of photoinduced enzyme inhibition is obtained with this method. PMID:21973207

  20. An improved procedure for the preparation of Ru(bpz3(PF62 via a high-yielding synthesis of 2,2’-bipyrazine

    Directory of Open Access Journals (Sweden)

    Danielle M. Schultz

    2015-01-01

    Full Text Available There has been a recent surge of interest in the use of transition metal polypyridyl complexes as visible light-absorbing photocatalysts for synthetic applications. Among the most attractive features of this approach is the availability of many known complexes with well-characterized photophysical and electrochemical properties. In particular, Ru(bpz32+ is a powerful photooxidant that has proven to be uniquely suited for oxidatively induced photoredox transformations. We present here a straightforward and high-yielding route to Ru(bpz3(PF62 that features an improved Pd-catalyzed synthesis of the 2,2’-bipyrazine ligand that is amenable to gram-scale preparations.

  1. Parallel ferromagnetic resonance and spin-wave excitation in exchange-biased NiFe/IrMn bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Marcos Antonio de, E-mail: marcossharp@gmail.com [Instituto de Física, Universidade Federal de Goiás, Goiânia, 74001-970 (Brazil); Pelegrini, Fernando [Instituto de Física, Universidade Federal de Goiás, Goiânia, 74001-970 (Brazil); Alayo, Willian [Departamento de Física, Universidade Federal de Pelotas, Pelotas, 96010-900 (Brazil); Quispe-Marcatoma, Justiniano; Baggio-Saitovitch, Elisa [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro, 22290-180 (Brazil)

    2014-10-01

    Ferromagnetic Resonance study of sputtered Ru(7 nm)/NiFe(t{sub FM})/IrMn(6 nm)/Ru(5 nm) exchange-biased bilayers at X and Q-band microwave frequencies reveals the excitation of spin-wave and NiFe resonance modes. Angular variations of the in-plane resonance fields of spin-wave and NiFe resonance modes show the effect of the unidirectional anisotropy, which is about twice larger for the spin-wave mode due to spin pinning at the NiFe/IrMn interface. At Q-band frequency the angular variations of in-plane resonance fields also reveal the symmetry of a uniaxial anisotropy. A modified theoretical model which also includes the contribution of a rotatable anisotropy provides a good description of the experimental results.

  2. Adsorption of formaldehyde and formyl intermediates on Pt, PtRu-, and PtRuMo-alloy surfaces: A density functional study

    Science.gov (United States)

    Cahyanto, Wahyu Tri; Shukri, Ganes; Agusta, Mohammad Kemal; Kasai, Hideaki

    2013-02-01

    Stable binding configuration for formaldehyde (H2CO) and formyl (HCO) adsorption on Pt, PtRu, and PtRuMo are studied within the frame of density functional theory (DFT). We address this study to investigate the role of Ru and Mo on the binding characteristic of formaldehyde and formyl adsorption with respect to interaction strength and charge analysis. Several binding conformation on all possible surface adsorption sites are considered in determining the most stable adsorption geometry on three surfaces. Our results show that the presence of Ru in PtRu and Mo in PtRuMo stabilize the formaldehyde and formyl, which are indicated by stronger bond strength. Further electronic structure analysis shows that the addition of Ru in PtRu and Mo in PtRuMo modifies the electronic structure of Pt's surface significantly. The presence of both impurities shifted the derived anti-bonding state - which is originally located below the fermi level in pure Pt surface - to be above the fermi level in PtRu and PtRuMo systems. This fact explains the stronger adsorption found on PtRu & PtRuMo as compared to pure Pt surface.

  3. Preparation of Sm–Ru bimetallic alloy films on Ru(0001) surface by vapour-deposition and annealing

    Indian Academy of Sciences (India)

    G Ranga Rao; H Nozoye

    2001-12-01

    Sm–Ru intermetallic surface alloy films were prepared by vacuum deposition and annealing of rare earth Sm on single crystal Ru(0001) surface. The Ru 3 and Sm 3 core level spectra clearly show the formation of surface alloy layers. XPS measurements on surface alloy film revealed an induced peak in the Ru3 region at lower binding energy by 1 eV compared to the bulk Ru (elemental) suggesting an electronic effect of alloying and Sm–Ru bond formation. The Sm 35/2 photoemission peak of Sm film consists of strong features characteristic of Sm(II) with electron configuration 46 (5\\ 6)2 and Sm(III) with electron configuration 46 (5\\ 6)3. It is observed that the Sm(II) feature decreases in intensity upon alloy formation with surface Ru atoms. Oxidation of these films with carbon monoxide indicates alloy breakdown due to the oxidation of Sm atoms selectively. Alloy oxidation also shows a clear shift of Sm 35/2 feature.

  4. Unidirectional Photo-induced Charge Separation and Thermal Charge Recombination of Cofacially Aligned Donor-Acceptor System Probed by Ultrafast Visible-Pump/Mid-IR-Probe Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeongmook; Lim, Manho; Chung, Young Keun; Kang, Youn K. [Seoul National Univ., Seoul (Korea, Republic of); Park, Jaeheung [Pusan National Univ., Busan (Korea, Republic of); Noh, Hee Chang [Sangmyung Univ., Seoul (Korea, Republic of)

    2014-02-15

    Similar to its precedent, [Ru(6-(2-cyclohexa-2',5'-diene-1,4-dione)-2,2':6',2''-terpyridine) (2,2':6',2-terpyridine)][PF6]2 (TQ{sub T}), this system has a cofacial alignment of terpyridine (tpy) ligand and quinonyl (Q) group, which facilitates an electron transfer through π-stacked manifold. Despite the presence of lowest-energy charge transfer transition from the Ru-based-HOMO-to-Q-based-LUMO (MQCT) predicted by theoretical calculations by using time-dependent density functional theory (TD-DFT), the experimental steady-state absorption spectrum does not exhibit such a band. The selective excitation to the Ru-based occupied orbitalsto-tpy-based virtual orbital MLCT state was thus possible, from which charge separation (CS) reaction occurred. The photo-induced CS and thermal charge recombination (CR) reactions were probed by using ultrafast visible-pump/mid-IR-probe (TrIR) spectroscopic method. Analysis of decay kinetics of Q and Q{sup -} state CO stretching modes as well as aromatic C=C stretching mode of tpy ligand gave time constants of <1 ps for CS, 1-3 ps for CR, and 10-20 ps for vibrational cooling processes. The electron transfer pathway was revealed to be Ru-tpy-Q rather than Ru-bpy-imidazol-Q.

  5. The extragalactic IR background

    CERN Document Server

    De Zotti, G; Mazzei, P; Toffolatti, L; Danese, L; De Zotti, G; Franceschini, A; Mazzei, P; Toffolatti, L; Danese, L

    1994-01-01

    Current limits on the intensity of the extragalactic infrared background are consistent with the expected contribution from evolving galaxies. Depending on the behaviour of the star formation rate and of the initial mass function, we can expect that dust extinction during early evolutionary phases ranges from moderate to strong. An example of the latter case may be the ultraluminous galaxy IRAS F10214 + 4724. The remarkable lack of high redshift galaxies in faint optically selected samples may be indirect evidence that strong extinction is common during early phases. Testable implications of different scenarios are discussed; ISO can play a key role in this context. Estimates of possible contributions of galaxies to the background under different assumptions are presented. The COBE/FIRAS limits on deviations from a blackbody spectrum at sub-mm wavelengths already set important constraints on the evolution of the far-IR emission of galaxies and on the density of obscured (``Type 2'') AGNs. A major progress in ...

  6. Methanol Electrooxidation on Smooth Platinum Modified with Ru: the Influence of Ru Coverage and Potentials on Oxidative Current and Products

    Institute of Scientific and Technical Information of China (English)

    WANG, Hong-Sen

    2003-01-01

    Methanol oxidation on smooth Pt electrode modified with different coverage of Ru was studied using cyclic voltammetry and potential step combined with differential electrochemical mass spectroscopy. The current efficiency of formed CO2 was calculated from faraday current and ion current of m/z = 44. The results show that Ru modified Pt electrode with the coverage of ca. 0.3 has the highest catalytic activity for methanol electrooxidation, I.e. Faraday current and the current efficiency of CO2at the low potentials reach to the maximum. In addition, Ru loses its co-catalytic properties at the high potentials.

  7. Surface studies by low energy ion beams: Cu/Ru(0001) and Cu/O/Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Y.G.; O`Connor, D.J.; MacDonald, R.J. [Newcastle Univ., NSW (Australia). Dept. of Physics; Wandelt, H. [Institut fur Physikalische und Theoretische Chemie der Universitat Bonn, Bonn (Germany).; Zee, H. van [Eindhoven University of Technology, Eindhoven (Netherlands) Dept. of Physics

    1993-12-31

    The surface structure of Cu on Ru(OOO1) has been studied by low energy Li{sup +} ion scattering. It was found that Cu forms pseudomorphic islands for two layers. The effects of Cu on an O-precovered RU(OOO1) surface has also been investigated using keV He{sup +} ions. The results show that during the deposition of Cu, O is displaced from the Ru surface and migrated onto the top of the surface of the growing overlayer. The floated out O has been tested, showing a disordered overlayer. 5 refs., 3 figs.

  8. Single neutron pick-up on {sup 104}Pd

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, M.R.D.; Andre, J.P.A.M. de; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L. [Universidade de Sao Paulo, SP (Brazil). Inst. de Fisica; Ukita, G.M. [Universidade de Santo Amaro, SP (Brazil). Faculdade de Psicologia

    2006-12-15

    Low-lying levels of {sup 103}Pd have been investigated through the (d,t) reaction on {sup 104}Pd, at an incident deuteron energy of 15.0 MeV. Outgoing particles were momentum analyzed by an Enge magnetic spectrograph and detected in nuclear emulsion plates, with an energy resolution of 8 keV. Previous (d,t) work suffered from a much worse resolution than that here achieved. A partial analysis of the data obtained is reported, referring to six out of the fourteen scattering angles for which data were obtained. Angular distributions associated with eight of the thirteen levels seen up to 1.1 MeV of excitation have been compared to DWBA one-neutron pick-up predictions. Both, the attributed excitation energy values and the transferred angular momenta are in excellent agreement with the results of other kind of experiments, as tabulated by the Nuclear Data Sheets. Some peculiar structure characteristics, associated with the yrast 5/2{sup +}, 3/2{sup +} and 7/2{sup +} states found in the Ru chain could be recognized also in {sup 103}Pd, pointing to the possibility of a more global understanding of this transitional mass region. (author)

  9. The IRS-1 signaling system.

    Science.gov (United States)

    Myers, M G; Sun, X J; White, M F

    1994-07-01

    Insulin-receptor substrate 1 (IRS-1) is a principal substrate of the receptor tyrosine kinase for insulin and insulin-like growth factor 1, and a substrate for a tyrosine kinase activated by interleukin 4. IRS-1 undergoes multisite tyrosine phosphorylation and mediates downstream signals by 'docking' various proteins that contain Src homology 2 domains. IRS-1 appears to be a unique molecule; however, 4PS, a protein found mainly in hemopoietic cells, may represent another member of this family.

  10. Annealing of RuO 2 and Ru Bottom Electrodes and Its Effects on the Electrical Properties of (Ba,Sr)TiO 3 Thin Films

    Science.gov (United States)

    Ahn, Joon-Hyung; Choi, Won-Youl; Lee, Won-Jae; Kim, Ho-Gi

    1998-01-01

    Crystalline structures and surface morphologies of annealed RuO2 and Ru thin films were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The annealing was performed in oxygen and argon ambient and high vacuum in the temperature range of 400 800° C. In oxygen ambient annealing, the surface morphology was drastically changed due to the evaporation of ruthenium dioxides in the form of RuO3 and RuO4. Annealed RuO2 thin film in vacuum was reduced to the Ru metal phase. The actual variation of RuO2 bottom electrodes during the deposition of (Ba,Sr)TiO3 (BST) thin films and the effects of the thermal stability of bottom electrodes on electrical properties of BST thin films deposited on RuO2/SiO2/Si were also investigated.

  11. Study of Ru{sub 2}VGe and Ru{sub 2}VSb: High-spin polarized and half-metallic Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, Idris Hamid; Gupta, Dinesh C. [Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior – 474011 (India)

    2015-06-24

    Electronic and magnetic properties of Ru{sub 2}VGe and Ru{sub 2}VSb have been investigated by ab-initio. The optimized equilibrium lattice parameters were found to be 6.032 Å for Ru{sub 2}VGe and 6.272 Å for Ru{sub 2}VSb. Both the materials have ferromagnetic ground states and V mainly contributes to the magnetic properties in these materials. The highly spin-polarized half-metallic materials have integral magnetic moments of 1.0 µ{sub B} for Ru{sub 2}VGe and 2.0 µ{sub B} for Ru{sub 2}VSb with an energy gap of 0.095 eV for Ru2VGe and 0.186 eV for Ru{sub 2}VSb in the spin-down channel.

  12. Beta decay of Tc-111 to Ru-111

    NARCIS (Netherlands)

    Pfeiffer, B; Lhersonneau, G; Dendooven, P; Honkanen, A; Huhta, M; Klockl, [No Value; Oinonen, M; Penttila, H; Persson, B.L.; Perajarvi, K; Wang, JC; Kratz, KL; Aysto, J

    1998-01-01

    The beta-decay of the very neutron-rich Tc-111 nucleus has been observed. A partial decay scheme of Ru-111 is presented, complementing the high-spin levels earlier reported in spontaneous fission work.

  13. β-delayed proton decay of 89Ru

    Institute of Scientific and Technical Information of China (English)

    李占奎; 徐树威; 于涌; 谢元祥; 王春芳; 邢建萍; 潘强岩; 胡青元; 李世红; 陈红艳; 张天梅

    2000-01-01

    89Ru was synthesized in the reaction of 58Ni (36Ar, 2p3n) on the basis of a "p-γ" coincidence measurement by using a He-jet tape transport system, and its p-delayed proton emission with a half-life of (1.1 ±0.2) s was investigated. The p-delayed proton spectrum of 89Ru populating the low-lying states in 88Mo was obtained, and the final state proton branching ratios to the low-lying 2+ and 4 + states in88Mo were estimated to be 100:6. Based on the statistical model calculations, the ground state spin of 89Ru was preliminarily assigned to be 5/2+ or 7/2±, and the mass excess of 89Ru was deduced to be -59.5 MeV.

  14. Dissociation of CH4 on Ni(111) and Ru(0001)

    DEFF Research Database (Denmark)

    Egeberg, Rasmus; Ullmann, S.; Alstrup, I.

    2002-01-01

    to clarify to what extent a similar effect is present in these systems. The apparent activation energies found were 74 +/- 10 and 51 +/- 6 kJ/mol on Ni(1 1 1) and Ru(0 0 0 1) respectively. On neither Ru(0 0 0 1) nor Ni(1 1 1) did we observe a significant decrease of the overall sticking coefficient when...... the terraces, Finally we have observed a large promotion of the sticking probability of CH4 on Ru(0 0 0 1) by increasing the surface temperature at a fixed gas temperature thus lending support to a mechanism where the dissociation of methane takes place over Ru atoms displaced normal to the surface....

  15. β-delayed proton decay of 89Ru

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    89Ru was synthesized in the reaction of 58Ni (36Ar, 2p3n) on the basis of a "p-γ" coincidence measurement by using a He-jet tape transport system, and its β-delayed proton emission with a half-life of (1.1±0.2) s was investigated. The β-delayed proton spectrum of 89Ru populating the low-lying states in 88Mo was obtained, and the final state proton branching ratios to the low-lying 2+ and 4+ states in 88Mo were estimated to be 100:6. Based on the statistical model calculations, the ground state spin of 89Ru was preliminarily assigned to be 5/2+ or 7/2±, and the mass excess of 89Ru was deduced to be -59.5 MeV.

  16. Isospin Distribution of Fragments in Reaction 96Ru+96Ru, 96Ru+96Zr, 96Zr+96Ru, and 96Zr+96Zr at Beam Energy 400 AMeV

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The isospin distribution of particles and fragments in collisions 96Ru+96Ru, 96Ru+96Zr, 96Zr+96Ru, and 96Zr+96Zr at beam energy 400 AMeV is studied with isospin dependent QMD model. We find the rapidity distribution of difference between neutron-proton number in neutron rich nucleus-nucleus collisions at intermediate energies is sensitive to the isospin dependent part of nuclear potential. The study of the N/Z ratio of nucleons, light charged particles (LCP) and intermediate mass fragments (IMF) shows that the isospin dependent part of nuclear potential drives IMF to be more isospin symmetric and emitted nucleons to be more neutron rich. We also study the time evolution of the isospin distribution

  17. Comprehensive meta-analysis of key immune-related adverse events from CTLA-4 and PD-1/PD-L1 inhibitors in cancer patients.

    Science.gov (United States)

    De Velasco, Guillermo; Je, Youjin; Bossé, Dominick; Awad, Mark M; Ott, Patrick A; Moreira, Raphael B; Schutz, Fabio A B; Bellmunt, Joaquim; Sonpavde, Guru; Hodi, F Stephen; Choueiri, Toni K

    2017-02-28

    Immune-related adverse events (irAEs) have been described with immune checkpoint inhibitors (ICIs), but the incidence and relative risk (RR) of irAEs associated with these drugs remains unclear. We selected five key irAEs from treatments with approved cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) inhibitors (ipilimumab, nivolumab or pembrolizumab, and atezolizumab, respectively) to better characterize their safety profile. We performed a meta-analysis of randomized phase II/III immunotherapy trials, with non-ICI control arms, conducted between 1996 and 2016. We calculated the incidence and RR of selected all-grade and high-grade gastrointestinal, liver, skin, endocrine, and pulmonary irAEs across the trials using random-effect models. Twenty-one trials were included, totaling 11,454 patients, of whom 6528 received an ICI (nivolumab, 1534; pembrolizumab, 1522; atezolizumab, 751; and ipilimumab, 2721) and 4926 had not. Compared to non-ICI arms, ICIs were associated with more all-grade colitis (RR 7.66, P ICI arms. Ipilimumab was associated with a higher risk of all-grade rash (P = 0.006) and high-grade colitis (P = 0.021) compared to PD-1/PD-L1 ICIs. Incidence of fatal irAE was ICIs are associated with a small but significant increase in risk of selected all-grade irAEs and high-grade gastrointestinal and liver toxicities. Although fatal irAEs remain rare, AEs should be recognized promptly as early interventions may alleviate future complications.

  18. Potassium-oxygen interactions on a Ru(001) surface

    Energy Technology Data Exchange (ETDEWEB)

    Hrbek, J.; Shek, M.L.; Xu, G.Q. (Brookhaven National Lab., Upton, NY (United States)); Sham, T.K. (Univ. of Western Ontario, London, Ontario (Canada))

    1992-10-01

    The interaction of potassium with oxygen has been examined using synchrotron-based photoemission and NEXAFS, thermal desorption, work function measurements, and isotope exchange. Potassium coverages on Ru(001) surface ranging from monolayer to multilayer were investigated. Oxygen coadsorbed with potassium at 80 K forms a potassium-dioxygen complex, where both peroxide and superoxide ions were identified. The complex has high thermal stability on the Ru(001) surface, decomposing and desorbing at T > 900 K. 52 refs., 14 figs., 2 tabs.

  19. Oxidation of Mg adsorbed on Ru(001): A photoemission study

    Energy Technology Data Exchange (ETDEWEB)

    Malik, I.J.; Hrbek, J. (Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)); Shek, M. (National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States)); Bzowski, A.; Kristof, P.; Sham, T.K. (Department of Chemistry, University of Western Ontario, London, Ontario NA6 5B7 (Canada))

    1992-07-01

    We studied the interaction of oxygen with Mg overlayers adsorbed on Ru(001). Soft x-ray synchrotron radiation was used to explore photoemission from the valence band, the O 2{ital p}, O 2{ital s}, and Mg 2{ital p} levels, as well as intra- and interatomic Auger processes. The photoemission results are complemented by thermal desorption data. The O/Mg/Ru system shows photoemission features characteristic of molecular orbitals of a dioxygen species.

  20. Alkali promotion of N-2 dissociation over Ru(0001)

    DEFF Research Database (Denmark)

    Mortensen, Jens Jørgen; Hammer, Bjørk; Nørskov, Jens Kehlet

    1998-01-01

    Using self-consistent density functional calculations, we show that adsorbed Na and Cs lower the barrier for dissociation of N2 on Ru(0001). Since N2 dissociation is a crucial step in the ammonia synthesis reaction, we explain in this way the experimental observation that alkali metals promote th...... the ammonia synthesis reaction over Ru catalysts. We also show that the origin of this effect is predominantly a direct electrostatic attraction between the adsorbed alkali atoms and the dissociating molecule....

  1. A model system for carbohydrates interactions on single-crystalline Ru surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thanh Nam

    2015-07-01

    In this thesis, I present a model system for carbohydrate interactions with single-crystalline Ru surfaces. Geometric and electronic properties of copper phthalocyanine (CuPc) on top of graphene on hexagonal Ru(0001), rectangular Ru(10 anti 10) and vicinal Ru(1,1, anti 2,10) surfaces have been studied. First, the Fermi surfaces and band structures of the three Ru surfaces were investigated by high-resolution angle-resolved photoemission spectroscopy. The experimental data and theoretical calculations allow to derive detailed information about the momentum-resolved electronic structure. The results can be used as a reference to understand the chemical and catalytic properties of Ru surfaces. Second, graphene layers were prepared on the three different Ru surfaces. Using low-energy electron diffraction and scanning tunneling microscopy, it was found that graphene can be grown in well-ordered structures on all three surfaces, hexagonal Ru(0001), rectangular Ru(10 anti 10) and vicinal Ru(1,1, anti 2,10), although they have different surface symmetries. Evidence for a strong interaction between graphene and Ru surfaces is a 1.3-1.7 eV increase in the graphene π-bands binding energy with respect to free-standing graphene sheets. This energy variation is due to the hybridization between the graphene pi bands and the Ru 4d electrons, while the lattice mismatch does not play an important role in the bonding between graphene and Ru surfaces. Finally, the geometric and electronic structures of CuPc on Ru(10 anti 10), graphene/Ru(10 anti 10), and graphene/Ru(0001) have been studied in detail. CuPc molecules can be grown well-ordered on Ru(10 anti 10) but not on Ru(0001). The growth of CuPc on graphene/Ru(10 anti 10) and Ru(0001) is dominated by the Moire pattern of graphene. CuPc molecules form well-ordered structures with rectangular unit cells on graphene/Ru(10 anti 10) and Ru(0001). The distance of adjacent CuPc molecules is 15±0.5 Aa and 13±0.5 Aa on graphene/Ru(0001

  2. DNA-binding, catalytic oxidation, C—C coupling reactions and antibacterial activities of binuclear Ru(II thiosemicarbazone complexes: Synthesis and spectral characterization

    Directory of Open Access Journals (Sweden)

    Arumugam Manimaran

    2012-07-01

    Full Text Available New hexa-coordinated binuclear Ru(II thiosemicarbazone complexes of the type {[(B(EPh3(COClRu]2L} (where, E = P or As; B = PPh3 or AsPh3 or pyridine; L = mononucleating NS donor of N-substituted thiosemicarbazones have been synthesized and characterized by elemental analysis, FT-IR, UV–vis and 31P{1H} NMR cyclic voltammetric studies. The DNA-binding studies of Ru(II complexes with calf thymus DNA (CT-DNA were investigated by UV–vis, viscosity measurements, gel-electrophoresis and fluorescence spectroscopy. The new complexes have been used as catalysts in C—C coupling reaction and in the oxidation of alcohols to their corresponding carbonyl compounds by using NMO as co-oxidant and molecular oxygen (O2 atmosphere at ambient temperature. Further, the new binucleating thiosemicarbazone ligands and their Ru(II complexes were also screened for their antibacterial activity against Klebsiella pneumoniae, Shigella sp., Micrococcus luteus, Escherichia coli and Salmonella typhi. From this study, it was found out that the activity of the complexes almost reaches the effectiveness of the conventional bacteriocide.

  3. Reação de bis-inserção de 1,2-difenilacetileno na ligação Pd-C de ciclometalados Bis insertion reaction of 1,2-diphenylacetilene into Pd-C bond of cyclometallated species

    Directory of Open Access Journals (Sweden)

    Sandra Regina Ananias

    2003-01-01

    Full Text Available The present paper deals with the bis-insertion reactions of 1,2-diphenylacetylene into Pd-C bond of the cyclopalladated complexes [Pd(dmba(µ-NCO]2 (1 and [Pd(dmba(MeCN2](NO3 (2 (dmba = N,N-dimethylbenzylamine, MeCN = acetonitrile. Two new complexes [Pd{PhC=CPh-CPh=CPhC6H4CH2N(CH 32}(NCO] (3 and [Pd{PhC=CPh-CPh=CPhC6H4CH2N(CH 32}(NO3 ] (4 were obtained and characterized by IR and NMR spectroscopy and elemental analysis.

  4. Enantioselective Michael reaction catalyzed by well-defined chiral ru amido complexes: isolation and characterization of the catalyst intermediate, ru malonato complex having a metal-carbon bond.

    Science.gov (United States)

    Watanabe, Masahito; Murata, Kunihiko; Ikariya, Takao

    2003-06-25

    Chiral Ru amido complexes promote asymmetric Michael addition of malonates to cyclic enones, leading to Michael adducts with excellent ee's, in which the chiral Ru amido complexes react with malonates to give isolable catalyst intermediates, chiral Ru malonato complexes bearing a metal bound C-nucleophile.

  5. Enhancement of Solar Fuel Production Schemes by Using a Ru,Rh,Ru Supramolecular Photocatalyst Containing Hydroxide Labile Ligands.

    Science.gov (United States)

    Rogers, Hannah Mallalieu; Arachchige, Shamindri M; Brewer, Karen J

    2015-11-16

    Polyazine-bridged Ru(II)Rh(III)Ru(II) complexes with two halide ligands, Cl(-) or Br(-), bound to the catalytically active Rh center are efficient single-component photocatalysts for H2O reduction to H2 fuel, with the coordination environment on Rh impacting photocatalysis. Herein reported is a new, halide-free Ru(II)Rh(III)Ru(II) photocatalyst with OH(-) ligands bound to Rh, further enhancing the photocatalytic reactivity of the structural motif. H2 production experiments using the photocatalyst bearing OH(-) ligands at Rh relative to the analogues bearing halides at Rh in solvents of varying polarity (DMF, CH3CN, and H2O) suggest that ion pairing with halides deactivates photocatalyst function, representing an exciting phenomenon to exploit in the development of catalysts for solar H2 production schemes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Kinetics of reduction of a RuO2(110) film on Ru by atomic hydrogen

    NARCIS (Netherlands)

    Ugur, D.; Storm, A.J.; Verberk, R.; Brouwer, J.C.; Sloof, W.G.

    2013-01-01

    The kinetics and the mechanism of reduction of a RuO2(110) film, grown thermally on a Ru(0001) surface, has been studied in the temperature range of 60-200 °C by using an atomic hydrogen flux of 2 × 1019 at. H m-2 s-1. The reduction kinetics is dominated by the creation of oxygen vacancies at the su

  7. PD-1 Blockers.

    Science.gov (United States)

    Wolchok, Jedd D

    2015-08-27

    Nivolumab and pembrolizumab are monoclonal antibodies that block the programmed death-1 receptor (PD-1, CD279), resulting in dis-inhibition of tumor-specific immune responses. Both are recently approved for use in the treatment of metastatic melanoma, and nivolumab as well for non-small cell lung cancer.

  8. Enhancement of perpendicular magnetic anisotropy and coercivity in ultrathin Ru/Co/Ru films through the buffer layer engineering

    Science.gov (United States)

    Kolesnikov, Alexander G.; Stebliy, Maxim E.; Ognev, Alexey V.; Samardak, Alexander S.; Fedorets, Aleksandr N.; Plotnikov, Vladimir S.; Han, Xiufeng; Chebotkevich, Ludmila A.

    2016-10-01

    We present results on a study of the interplay between microstructure and the magnetic properties of ultrathin Ru/Co/Ru films with perpendicular magnetic anisotropy (PMA). To induce PMA in the Co layer, we experimentally determined thicknesses of the buffer and capping layers of Ru. The maximum value of PMA was observed for the Co thickness of 0.9 nm with the 3 nm thick capping layer. The effective anisotropy field (H eff) and coercive force (H c) of the Co layer are very sensitive to the Ru buffer layer thickness (t b). The values of H eff and H c increase approximately by two and ten times, correspondingly, when t b changes from 6 to 20 nm, owing to an increase in volume fraction of the crystalline phase as a result of the grains’ growth. PMA is found to be mainly enhanced by elastic strains induced by the lattice mismatch on the Ru/Co and Co/Ru interfaces, leading to the deformation of the Co lattice. The surface impact is determined to be less than 10% of the magneto-elastic contribution to the effective anisotropy. Observation of the magnetic domain structure by means of polar Kerr microscopy reveals that out-of-plane magnetization reversal occurs through the nucleation, growth, and annihilation of domains, where the average size drastically rises with the increasing t b.

  9. Study on Chemisorption and Desorption of Hydrogen and Nitrogen on Ru-based Ammonia Synthesis Catalyst

    Institute of Scientific and Technical Information of China (English)

    祝一锋; 李小年

    2003-01-01

    The effects of promoters K,Ba,Sm,on the chemisorption and desorption of hydrogen and nitrogen,dispersion of metallic Ru and catalytic activity of active carbon(AC) supported ruthenium catalyst for ammonia synthesis have been studied by means of pulse chromatography,temperature-programmed desorption,and activity test,Promoters K,Ba and Sm increased the activity of Ru/AC catalysts for ammonia synthesis significantly,and particularly,potassium exhibited the best promotion on the activity because of the strong electronic donation to metallic Ru.Much higher activity can be obtained for Ru/AC catalyst with binary or triple promoters.The activity of Ru/AC catalyst is dependent on the adsorption of hydrogen and nitrogen.The high activity of catalyst could be ascribed to strong dissociation of nitrogen on the catalyst surface.Strong adsorption of hydrogen would inhibit the adsorption of nitrogen,resulted in decrease of the catalytic activity.Ru/AC catalyst promoted by Sm2O3 shows the best dispersion of metallic Ru,since the partly reduced SmO2 on the surface modifies the morphology of active sites and favors the dispersion of metallic Ru.The activity of Ru/AC catalysts is in accordance to the corresponding amount of nitrogen chemisorption and the desorption activation enery of nitrogen.The desorption activation energy for nitrogen decreases in the order of Ru>Ru-Ba>Ru-Sm>Ru-Bs-Sm>Ru-K>Ru-K-Bm>Ru-K-Ba>Ru-K-Ba-Sm,just opposite to the order or catalytic activity,suggesting that the ammonia synthesis over Ru-based catalyst is controlled by the step of dissociation of nitrogen.

  10. Accurate estimation of dose distributions inside an eye irradiated with {sup 106}Ru plaques

    Energy Technology Data Exchange (ETDEWEB)

    Brualla, L.; Sauerwein, W. [Universitaetsklinikum Essen (Germany). NCTeam, Strahlenklinik; Sempau, J.; Zaragoza, F.J. [Universitat Politecnica de Catalunya, Barcelona (Spain). Inst. de Tecniques Energetiques; Wittig, A. [Marburg Univ. (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    2013-01-15

    Background: Irradiation of intraocular tumors requires dedicated techniques, such as brachytherapy with {sup 106}Ru plaques. The currently available treatment planning system relies on the assumption that the eye is a homogeneous water sphere and on simplified radiation transport physics. However, accurate dose distributions and their assessment demand better models for both the eye and the physics. Methods: The Monte Carlo code PENELOPE, conveniently adapted to simulate the beta decay of {sup 106}Ru over {sup 106}Rh into {sup 106}Pd, was used to simulate radiation transport based on a computerized tomography scan of a patient's eye. A detailed geometrical description of two plaques (models CCA and CCB) from the manufacturer BEBIG was embedded in the computerized tomography scan. Results: The simulations were firstly validated by comparison with experimental results in a water phantom. Dose maps were computed for three plaque locations on the eyeball. From these maps, isodose curves and cumulative dose-volume histograms in the eye and for the structures at risk were assessed. For example, it was observed that a 4-mm anterior displacement with respect to a posterior placement of a CCA plaque for treating a posterior tumor would reduce from 40 to 0% the volume of the optic disc receiving more than 80 Gy. Such a small difference in anatomical position leads to a change in the dose that is crucial for side effects, especially with respect to visual acuity. The radiation oncologist has to bring these large changes in absorbed dose in the structures at risk to the attention of the surgeon, especially when the plaque has to be positioned close to relevant tissues. Conclusion: The detailed geometry of an eye plaque in computerized and segmented tomography of a realistic patient phantom was simulated accurately. Dose-volume histograms for relevant anatomical structures of the eye and the orbit were obtained with unprecedented accuracy. This represents an important step

  11. Atomic hydrogen interaction with Ru(1010).

    Science.gov (United States)

    Vesselli, E; Comelli, G; Rosei, R

    2004-05-01

    The interaction of atomic hydrogen with clean and deuterium precovered Ru(1010) was studied by means of temperature-programmed desorption (TPD) spectroscopy. Compared to molecular hydrogen experiments, after exposure of the clean surface to gas-phase atomic hydrogen at 90 K, two additional peaks grow in the desorption spectra at 115 and 150 K. The surface saturation coverage, determined by equilibrium between abstraction and adsorption reactions, is 2.5 monolayers. Preadsorbed deuterium abstraction experiments with gas-phase atomic hydrogen show that a pure Eley-Rideal mechanism is not involved in the process, while a hot atom (HA) kinetics describes well the reaction. By least-squares fitting of the experimental data, a simplified HA kinetic model yields an abstraction cross section value of 0.5 +/- 0.2 angstroms2. The atomic hydrogen interaction with an oxygen precovered surface was also studied by means of both TPD and x-ray photoelectron spectroscopy: oxygen hydrogenation and water production take place already at very low temperature (90 K).

  12. Face to phase with RU Lupi

    CERN Document Server

    Gahm, Gösta F; Walter, Frederick M; Petrov, Peter P; Herczeg, Gregory J

    2013-01-01

    We present new results on the classical T Tauri star RU Lupi based on three observing runs collecting high-resolution spectra, complementary NIR spectra, multicolour photometric data, and X-ray observations. The photospheric absorption lines are weakened. This veiling becomes extremely strong on occasion, and we show that this effect is due to narrow emission lines that fill in the photospheric lines. The blue-shifted wings in the optical emission lines of He I, attributed to a stellar wind, are remarkably stable in equivalent width. In contrast, the red-shifted wings change dramatically in strength depending on rotational phase. From the pattern of variability we infer that these wings originate in accreting gas close to the star, and that the accretion funnels are bent and trail the hot spot. Forbidden emission lines are very stable over the entire observing period and originate in the disk wind. A system of narrow blue-shifted absorption features seen in lines of Ca II and Na I can be traced to a disk wind...

  13. PD-1, gender, and autoimmunity

    Science.gov (United States)

    Dinesh, Ravi K.; Hahn, Bevra H.; Singh, Ram Pyare

    2010-01-01

    Programmed death 1 (PD-1) and its ligands (PD-L1 and PD-L2) are responsible for inhibitory T cell signaling that helps mediate the mechanisms of tolerance and immune homeostasis. The PD-1:PD-L signaling pathway has been shown to play an important role in a variety of diseases, including autoimmune conditions, chronic infection, and cancer. Recently, investigators have explored the role of sex hormones in modulating the pathway in autoimmune conditions. Exploring the effects of sex hormones on the PD-1:PD-L pathway could shed light on the gender biased nature of many autoimmune conditions as well as aide in the development of therapeutics targeting the immune system. PMID:20433954

  14. IR seeker simulator and IR scene generation to evaluate IR decoy effectiveness; 2005BU1-EO

    NARCIS (Netherlands)

    Jong, W. de; Dam, F.A.M.; Kunz, G.J.; Schleijpen, H.M.A.

    2005-01-01

    IR decoys can be an effective countermeasure against IR guided anti ship missiles. However, it's not so easy to determine how the decoys should be deployed to get maximum effectiveness. A limitation of trials is that results are obtained for the specific trial condition only. Software tools have bee

  15. Standard enthalpies of formation of selected Ru{sub 2}YZ Heusler compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ming, E-mail: myin1@hawk.iit.edu; Nash, Philip

    2015-06-15

    Highlights: • Standard enthalpies of formation of Ru{sub 2}YZ were measured using a drop calorimeter. • Result of L2{sub 1} structured compounds agrees with first principles data. • Lattice parameters and related phase relationships were consistent with literature data. • Ru{sub 2}HfSn, Ru{sub 2}TiSn, Ru{sub 2}VGa, Ru{sub 2}VSi, Ru{sub 2}VSn of L2{sub 1} structure were reported for the first time. - Abstract: The standard enthalpies of formation of selected ternary Ru-based Heusler compounds Ru{sub 2}YZ (Y = Fe, Hf, Mn, Ti, V; Z = Al, Ga, In, Si, Ge, Sn) were measured using high temperature direct reaction calorimetry. The measured enthalpies of formation (in kJ/mole of atoms) of the Heusler compounds are, Ru{sub 2}FeGe (−19.7 ± 3.3); Ru{sub 2}HfSn (−24.9 ± 3.6); Ru{sub 2}MnSi (−46.0 ± 2.6); Ru{sub 2}MnGe (−29.7 ± 1.0); Ru{sub 2}MnSn (−20.6 ± 2.4); Ru{sub 2}TiSi (−94.9 ± 4.0); Ru{sub 2}TiGe (−79.1 ± 3.2); Ru{sub 2}TiSn (−60.6 ± 1.8); Ru{sub 2}VSi (−55.9 ± 1.7);for the B2-structured compounds, Ru{sub 2}FeSi (−28.5 ± 0.8); Ru{sub 2}HfAl (−70.8 ± 1.9); Ru{sub 2}MnAl (−32.3 ± 1.9); Ru{sub 2}MnGa (−25.3 ± 3.0); Ru{sub 2}TiAl (−62.7 ± 3.5); Ru{sub 2}VAl (−30.9 ± 1.6); Ru{sub 2}ZrAl (−64.5 ± 1.5). Values were compared with those from published first principles calculations and the OQMD (Open Quantum Materials Database). Lattice parameters of these compounds were determined using X-ray diffraction analysis (XRD). Microstructures were identified using scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS)

  16. Optical constants of infrared (IR) materials in the IR region

    Science.gov (United States)

    Nagendra, C. L.; Thutupalli, G. K. M.

    1992-01-01

    Optical constants, i.e., refractive index 'n' and absorption index 'k' of the IR materials, Ge, ThF4, CdTe and CdSe have been determined, through spectrophotometric method, in the IR region from 2.5 to 15 microns. It is seen that all these films are transparent in the IR region, and the optical constants of the films deposited at elevated temperatures (T = 200 C) are unaffected, even after subjecting to severe environs such as humidity and thermal shock/cycling. Making use of Ge/ThF4 and CdTe/CdSe coating combinations, IR antireflection coatings (ARCs) which can find applications in space-borne electrooptical systems have been successfully designed and developed. The resulting ARCs have not only efficient optical properties, low reflection loss and high transmission, but are also durable against adverse environments.

  17. Vibrationally enhanced associative photodesorption of H{sub 2} (D{sub 2}) from Ru(0001). Quantum and classical approaches

    Energy Technology Data Exchange (ETDEWEB)

    Vazhappilly, Tijo Joseph

    2008-04-15

    This thesis investigates the femtosecond laser induced associative photodesorption of hydrogen, H{sub 2}, and deuterium, D{sub 2}, from a ruthenium metal surface. One of the goals of the present thesis is to suggest, on the basis of theoretical simulations, strategies to control/enhance the photodesorption yield from Ru(0001). For this purpose, we suggest a hybrid scheme to control the reaction, where the adsorbate vibrations are initially excited by an infrared (IR) pulse, prior to the vis pulse. Both adiabatic and non-adiabatic representations for photoinduced desorption problems are employed here. The adiabatic representation is realized within the classical picture using Molecular Dynamics (MD) with electronic frictions. In a quantum mechanical description, non-adiabatic representations are employed within open-system density matrix theory. The time evolution of the desorption process is studied using a two-mode reduced dimensionality model with one vibrational coordinate and one translational coordinate of the adsorbate. The ground and excited electronic state potentials, and dipole function for the IR excitation are taken from first principles. The IR driven vibrational excitation of adsorbate modes with moderate efficiency is achieved by (modified) {pi}-pulses or/and optimal control theory. The fluence dependence of the desorption reaction is computed by including the electronic temperature of the metal calculated from the two-temperature model. We then employed the IR+vis strategy in both models. Here, we found that vibrational excitation indeed promotes the desorption of hydrogen and deuterium. (orig.)

  18. The Spectroscopic and Conductive Properties of Ru(II Complexes with Potential Anticancer Properties

    Directory of Open Access Journals (Sweden)

    Adebayo A. Adeniyi

    2014-01-01

    Full Text Available Different density functional methods (DFT have been used to optimize and study the chemistry of five potential anticancer complexes in terms of their electronic, conductive, and spectroscopic properties. Many of the computed properties in addition to the IR and QTAIM analysis of the NMR are dipole moment vector (μi, linear polarizability tensor (αij, first hyperpolarizability tensors (βijk, polarizability exaltation index (Γ, and chemical hardness (η of the complexes. Stable low energy geometries are obtained using basis set with effective core potential (ECP approximation but, in the computation of atomic or molecular properties, the metal Ru atom is better treated with higher all electron basis set like DGDZVP. The spectroscopic features like the IR of the metal-ligand bonds and the isotropic NMR shielding tensor of the coordinated atoms are significantly influenced by the chemical environment of the participating atoms. The carboxylic and pyrazole units are found to significantly enhance the polarizabilities and hyperpolarizabilities of the complexes while the chloride only improves the polarity of the complexes. Fermi contacts (FC have the highest effect followed by the PSO among all the four Ramsey terms which defined the total spin-spin coupling constant J (HZ of these complexes.

  19. Influence of alkali promoters in the selective hydrogenation of 3-methyl-2-butenal over Ru/SiO{sub 2} catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Waghray, A.; Wang, Jian; Oukaci, R.; Blackmond, D.G. [Univ. of Pittsburgh, PA (United States)

    1992-07-09

    The addition of potassium as a promoter to a Ru/SiO{sub 2} catalyst resulted in a striking shift in product selectivity in the hydrogenation of 3-methyl-2-butenal. The rate of hydrogenation of the C=O bond to produce the unsaturated alcohol increased concomitant with a decrease in the rate of C=C hydrogenation. IR spectroscopy showed a strong perturbation of the C=O bond for the alkali-promoted catalyst, and volumetric chemisorption and TPD results suggested that the alkali species blocked adsorption at low-coordination Ru sites. These adsorption and reaction studies suggest that polarization of the adsorbed substrate at the C=O bond is responsible for the significant shift in product selectivity upon alkali promotion. This work combines spectroscopic tools with the use of the catalytic reaction itself as a probe of catalyst surface chemistry. 40 refs., 6 figs., 3 tabs.

  20. Synthesis, spectral, thermal, X-ray single crystal of new RuCl₂(dppb)diamine complexes and their application in hydrogenation of Cinnamic aldehyde.

    Science.gov (United States)

    Warad, Ismail; Al-Hussain, Hanan; Al-Far, Rawhi; Mahfouz, Refaat; Hammouti, Belkheir; Hadda, Taibi Ben

    2012-09-01

    The preparation of new three trans-[RuCl(2)(dppb)(N-N)] with mixed diamine (N-N) and 1,4-bis-(diphenylphosphino)butane (dppb) ligands, starting from RuCl(2)(PPh(3))(3) as precursor is presented. The complexes are characterized on the basis of elemental analysis, IR, (1)H, (13)C and (31)P{(1)H}NMR, FAB-MS, TG/DTA and single crystal X-ray diffraction studies. Complex (2L(1)) crystallizes in the monoclinic unit cells with the space group P2(1). The catalysts are evaluated for their Cinnamic aldehyde hydrogenation. The catalysts show excellent activity and selectivity for the unsaturated carbonyl compound under mild conditions.

  1. Transient mid-IR study of electron dynamics in TiO2 conduction band.

    Science.gov (United States)

    Sá, Jacinto; Friedli, Peter; Geiger, Richard; Lerch, Philippe; Rittmann-Frank, Mercedes H; Milne, Christopher J; Szlachetko, Jakub; Santomauro, Fabio G; van Bokhoven, Jeroen A; Chergui, Majed; Rossi, Michel J; Sigg, Hans

    2013-04-07

    The dynamics of TiO2 conduction band electrons were followed with a novel broadband synchrotron-based transient mid-IR spectroscopy setup. The lifetime of conduction band electrons was found to be dependent on the injection method used. Direct band gap excitation results in a lifetime of 2.5 ns, whereas indirect excitation at 532 nm via Ru-N719 dye followed by injection from the dye into TiO2 results in a lifetime of 5.9 ns.

  2. Advanced IR imaging seeker program

    Science.gov (United States)

    Aguiera, R. A.

    1980-05-01

    An advanced IR Imaging Seeker System was developed which is compatible with the Hellfire Missile System mission. A technical overview of this program and current status is presented. The IR imaging seeker was tested during late 1979 and early 1980. This seeker utilizes a 1024 element InAsSb/silicon hybrid focal plane array (FPA) operating at 77 degrees K and IR-sensitive in the 2.4-4.0 micrometer wavelength region. A multimode tracker provides improved tracking capability for operation against targets in a high clutter background.

  3. High density plasma reactive ion etching of Ru thin films using non-corrosive gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Su Min; Garay, Adrian Adalberto; Lee, Wan In; Chung, Chee Won, E-mail: cwchung@inha.ac.kr

    2015-07-31

    Inductively coupled plasma reactive ion etching (ICPRIE) of Ru thin films patterned with TiN hard masks was investigated using a CH{sub 3}OH/Ar gas mixture. As the CH{sub 3}OH concentration in CH{sub 3}OH/Ar increased, the etch rates of Ru thin films and TiN hard masks decreased. However, the etch selectivity of Ru films on TiN hard masks increased and the etch slope of Ru film improved at 25% CH{sub 3}OH/Ar. With increasing ICP radiofrequency power and direct current bias voltage and decreasing process pressure, the etch rates of Ru films increased, and the etch profiles were enhanced without redeposition on the sidewall. Optical emission spectroscopy and X-ray photoelectron spectroscopy were employed to analyze the plasma and surface chemistry. Based on these results, Ru thin films were oxidized to RuO{sub 2} and RuO{sub 3} compounds that were removed by sputtering of ions and the etching of Ru thin films followed a physical sputtering with the assistance of chemical reaction. - Highlights: • Etching of Ru films in CH{sub 3}OH/Ar was investigated. • High selectivity and etch profile with high degree of anisotropy were obtained. • XPS analysis was examined to identify the etch chemistry. • During etching Ru was oxidized to RuO{sub 2} and RuO{sub 3} can be easily sputtered off.

  4. Production of C-Fe-Pd nanocomposites via Infra-red radiation and its structural characterization

    Science.gov (United States)

    Kovtun, A. V.; Dzidziguri, E. L.; Muratov, D. G.

    2016-08-01

    The objective of the present study is to produce C-Fe-Pd nanocomposites using pyrolyzed infrared (IR) radiation. The structural characterization was analyzed using X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray fluorescence analysis. In addition, the size of metal nanocomposites as a function of the pyrolysis temperature, and its distribution within the carbon matrix is also characterized.

  5. Unsupported PVA- and PVP-stabilized Pd nanoparticles as catalyst for nitrite hydrogenation in aqueous phase

    NARCIS (Netherlands)

    Zhao, Y.; Baeza, J.A.; Koteswara Rao, N.; Calvo, L.; Gilarranz, M.A.; Li, Y.D.; Lefferts, L.

    2014-01-01

    Pd colloids stabilized with polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) have been prepared, characterized with TEM, zeta potential measurements, CO chemisorption in aqueous phase, and ATR-IR spectroscopy using CO as a probe molecule, and finally tested for performance in nitrite hydrogena

  6. Convergent study of Ru-ligand interactions through QTAIM, ELF, NBO molecular descriptors and TDDFT analysis of organometallic dyes

    Science.gov (United States)

    Sánchez-Coronilla, Antonio; Sánchez-Márquez, Jesús; Zorrilla, David; Martín, Elisa I.; de los Santos, Desireé M.; Navas, Javier; Fernández-Lorenzo, Concha; Alcántara, Rodrigo; Martín-Calleja, Joaquín

    2014-08-01

    We report a theoretical study of a series of Ru complexes of interest in dye-sensitised solar cells, in organic light-emitting diodes, and in the war against cancer. Other metal centres, such as Cr, Co, Ni, Rh, Pd, and Pt, have been included for comparison purposes. The metal-ligand trends in organometallic chemistry for those compounds are shown synergistically by using three molecular descriptors: quantum theory of atoms in molecules (QTAIM), electron localisation function (ELF) and second-order perturbation theory analysis of the natural bond orbital (NBO). The metal-ligand bond order is addressed through both delocalisation index (DI) of QTAIM and fluctuation index (λ) of ELF. Correlation between DI and λ for Ru-N bond in those complexes is introduced for the first time. Electron transfer and stability was also assessed by the second-order perturbation theory analysis of the NBO. Electron transfer from the lone pair NBO of the ligands toward the antibonding lone pair NBO of the metal plays a relevant role in stabilising the complexes, providing useful insights into understanding the effect of the 'expanded ligand' principle in supramolecular chemistry. Finally, absorption wavelengths associated to the metal-to-ligand charge transfer transitions and the highest occupied molecular orbital (HOMO)--lowest unoccupied molecular orbital (LUMO) characteristics were studied by time-dependent density functional theory.

  7. [Pd(acac)(L)2][BF4] (L = morpholine, diethylamine, dibutylamine, dioctylamine): Synthesis, structure and their catalytic activity

    Science.gov (United States)

    Suslov, D. S.; Bykov, M. V.; Ratovskii, G. V.; Abramov, P. A.; Pahomova, M. V.; Ushakov, I. A.; Voronov, V. K.; Tkach, V. S.

    2017-04-01

    Cationic acetylacetonate bis(secondary amine) palladium (II) complexes were synthesized by nitrile substitution of [Pd(acac)(MeCN)2][BF4] with L (L = morpholine, diethylamine, dibutylamine, dioctylamine) which yielded [Pd(acac)(L)2][BF4] as a mononuclear species with chelating acac ligand. An X-ray diffraction, NMR, IR and DFT study of [Pd(acac){morpholine}2][BF4] establishes the presence of hydrogen bonding between the morpholine ligand and [BF4]- anion. Crystallographic defects in the crystal and presence of pseudocrystalline structure in solution of [Pd(acac){morpholine}2][BF4] were assumed to explain IR spectra features. Preliminary investigations into the polymerization of norbornene, dimerization of styrene, and telomerization of 1,3-butadiene with diethylamine were performed.

  8. Abnormal infrared effects of nanometer scale thin film material of PtPd alloy in CO adsorption

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nanometer scale thin film material of PtPd alloy supported on glassy carbon (nm-PtPd/GC) was prepared by the electrochemical codeposition method under cyclic voltammetric conditions. STM patterns demonstrated that the prepared thin films are composed of layered crystallites in elliptic form. Electrochemical in situ FTIRS studies explored the abnormal infrared effects (AIREs) of nmPtPd/GC for CO adsorption, which are ( i ) the remarkable enhancement of IR absorption, (ii) the inversion of COad band direction, and (iii) notable increase in the full width at half maximum (FWHM) of COad bands. The results demonstrated also that the enhancement factor of IR absorption varies with the thickness of PtPd alloy film and has reached a maximum value of 38.3 under the experimental conditions.

  9. Results of IR working group

    Energy Technology Data Exchange (ETDEWEB)

    Ritson, D. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)]|[Superconducting Super Collider Lab., Dallas, TX (United States)

    1992-03-01

    The IP luminosity at the Eloisatron will direct very large fluxes of hadronic debris into the IR quads. For instance at 1.10{sup 35} cm{sup 2}/sec the flux corresponds to 180 kilowatts. Already at the SSC fluxes in the neighborhood of 2 kilowatts are expected to require special handling. Scaling from SSC design experience we propose a configuration for the first IR quads at the Eloisatron capable of handling the heat load and radiation problems.

  10. Rahasäru veeretas viisimünti / Inna Grünfeldt

    Index Scriptorium Estoniae

    Grünfeldt, Inna, 1961-

    2008-01-01

    Folkloorifestival Viru Säru, mille teemaks seekord "Raha, rikkus ja vaesus", katsus Kadrinas kavasid. Žüriisse kuulusid Viru Säru kunstiline juht Igor Tõnurist, rahvamuusik Margus Veenre ja rahvatantsujuht Angela Arraste. Ka nende arvamused kavade kohta

  11. Microwave-assisted Synthesis of Arene Ru(Ⅱ) Complex [(η6-C6H6) Ru(H2iiP) Cl] Cl in SiC Vessel%SiC管中微波辅助芳烃钌(Ⅱ)化合物[(η6-C6H6)Ru(H2iiP)Cl]Cl的合成

    Institute of Scientific and Technical Information of China (English)

    吴琼; 梅文杰; 吴韦黎; 陈燕华; 曾玲莉; 郑文杰

    2013-01-01

    使用SiC管为反应容器,在微波辐射条件下以[(6-C6H6)RuCl2]2为原料与2-(吲哚基)咪唑[4,5-f]-[1,10]菲啰啉(H2iiP)反应,制得芳烃钌(Ⅱ)化合物[(η6-C6H6)Ru(H2iiP) C1]Cl(1),并对其进行了表征.采用正交实验法确定反应的最佳合成条件为:投料比n([(η6-C6 H6)RuCl2]2)∶n(H2iiP)=1∶2.2,反应温度90℃,微波辐射时间30 min.该反应的平均产率达到96.0%,反应产率的相对标准偏差(RSD)为1.28%,说明微波辐射条件下,在SiC管中能够高产率地制备芳烃钌化合物,并且反应具有良好的重现性.进一步采用MTT方法研究发现,芳烃钌(Ⅱ)化合物1能够选择性抑制MCF-7乳腺癌的生长.%Arene Ru(Ⅱ) complex [(η6-C6H6) Ru(H2iiP) Cl] Cl(1) was synthesized using [(η6-C6H6)·RuCl2] 2 and 2-indole-3-imidazole [4,5-f] [1,10] phenanthroline (H2 iiP) as raw material under microwave irradiation.The target compound was characterized by means of elemental analysis,ESI-MS,IR and NMR.The best craft condition determined by orthogonal test is that reactant molar ratio of 1.0 ∶ 2.2,the reaction temperature of 90 ℃ and the microwave irradiation time of 30 min.Then the average yield of 96.0% and RSD of 1.28% confirmed that microwave-assisted synthesis of arene Ru(Ⅱ) complex in SiC vessel gives a good stability and reiteration.The antitumor activity of arene Ru (Ⅱ) complex 1 was determined by MTT assay and the results showed that complex 1 could selectively inhibit the growth of MCF-7,indicating its potential utility in chemotherapy.

  12. Synthesis, Crystal Structure and Electrochemical Properties of Complex [Ru2 (μ-O2CCH3)4 (H2O)2] PF6%配合物[Ru2(μ-O2CCH3)4(H2O)2]PF6的合成、表征及电化学性质

    Institute of Scientific and Technical Information of China (English)

    严生虎; 姜冬明; 张跃; 刘建武; 沈介发

    2011-01-01

    The title compound, [Ru2 (μ-O2CCH3)4 (H2O)2] PF6, was prepared by treating Ru2 (O2 CCH3)4C1 with methanol aqueous solution at the presence of Ag2SO4 and NH4PF6 through coordinating process. The compound was characterized by elemental analysis, IR spectra, cyclic voltammetry and X-ray single crystal structure analysis. The result reveals that the compound crystallizes in the monoclinic system with space group at C2/c, and a =1. 9 52 3 (9) nm, b = 1. 2 83 0 (6) nm, c =0. 846 8 (4) nm, β=93. 11 (10) and Z = 4. Thermogravimetric analysis was carried out to study the mechanism of thermal decomposition of the complex. The electrochemical property of ruthenium complex were studied by means of cyclic voltametry, the results show that electron transfer between Ru (II) and Ru (III) in electrolysis is quasi-reversible process.%[Ru2(μ-O2CCH3)4(H2O)2]PF6是以Ru2( O2CCH3)4Cl为前体配合物,在甲醇水(体积比7 ∶ 1)溶液中用Ag2SO4和NH4PF6进行脱氯配位反应而得.用元素分析、红外光谱、热重分析、循环伏安、X-衍射单晶结构分析等对其进行表征.晶体结构表明,标题化合物的晶体属单斜晶系,空间群为C2/c,晶胞参数为a=1.9 523 (9) nm,b=1.2830 (6) nm,c=0.8468 (4) nm,β=93.11 (10)°,Z=4.通过热失重分析研究配合物的热分解机理.用循环伏安法对其电化学性质进行表征,结果为一对准可逆的氧化还原峰,表明该配合物的中心金属2价钌原子Ru (Ⅱ)与3价钌原子Ru (Ⅲ)之间存在电子转移.

  13. Bottom-up fabrication of graphene nanostructures on Ru(1010).

    Science.gov (United States)

    Song, Junjie; Zhang, Han-jie; Cai, Yiliang; Zhang, Yuxi; Bao, Shining; He, Pimo

    2016-02-01

    Investigations on the bottom-up fabrication of graphene nanostructures with 10, 10'-dibromo-9, 9'-bianthryl (DBBA) as a precursor on Ru(1010) were carried out using scanning tunnelling microscopy (STM) and density functional theory (DFT) calculations. Upon annealing the sample at submonolayer DBBA coverage, N = 7 graphene nanoribbons (GNRs) aligned along the [1210] direction form. Higher DBBA coverage and higher annealing temperature lead to the merging of GNRs into ribbon-like graphene nanoflakes with multiple orientations. These nanoflakes show different Moiré patterns, and their structures were determined by DFT simulations. The results showed that GNRs possess growth preference on the Ru(1010) substrate with a rectangular unit cell, and GNRs with armchair and zigzag boundaries are obtainable. Further DFT calculations suggest that the interaction between graphene and the substrate controls the orientations of the graphene overlayer and the growth of graphene on Ru(1010).

  14. Atomic states and properties of Ru-electrocatalyst

    Institute of Scientific and Technical Information of China (English)

    PENG Hong-jian; XIE You-qing; WEI De-liang

    2006-01-01

    Using the one-atom theory(OA), the atomic states of Ru-electrocatalyst with hcp structure was determined as [Kr](4dn)3.78(4dc)2.22(5sc)1.77(5sf)0.23. The potential curve, elasticity and the temperature dependence of linear thermal expansion coefficient and bulk modulus of hcp-Ru were calculated quantitatively. The atomic states of this metal with fcc and bcc structure and liquid state were also studied. According to its atomic states, the relationship between the atomic states and catalytic performance was explained qualitatively and these supplied Ru-metal and electrocatalyst with complete data for optimum designation in accordance with metal material systematic sicence.

  15. Ternary Pt-Ru-Ni catalytic layers for methanol electrooxidation prepared by electrodeposition and galvanic replacement

    OpenAIRE

    Athanasios ePapaderakis; Nikolaos ePliatsikas; Chara eProchaska; Kalliopi M. Papazisi; Balomenou, Stella P.; Dimitrios eTsiplakides; Panagiotis ePatsalas; Sotiris eSotiropoulos

    2014-01-01

    Ternary Pt-Ru-Ni deposits on glassy carbon substrates, Pt-Ru(Ni)/GC, have been formed by initial electrodeposition of Ni layers onto glassy carbon electrodes, followed by their partial exchange for Pt and Ru, upon their immersion into equimolar solutions containing complex ions of the precious metals. The overall morphology and composition of the deposits has been studied by SEM microscopy and EDS spectroscopy. Continuous but nodular films have been confirmed, with a Pt ÷ Ru ÷ Ni % bulk atomi...

  16. Molecularly imprinted Ru complex catalysts integrated on oxide surfaces.

    Science.gov (United States)

    Muratsugu, Satoshi; Tada, Mizuki

    2013-02-19

    Selective catalysis is critical for the development of green chemical processes, and natural enzymes that possess specialized three-dimensional reaction pockets with catalytically active sites represent the most sophisticated systems for selective catalysis. A reaction space in an enzyme consists of an active metal center, functional groups for molecular recognition (such as amino acids), and a surrounding protein matrix to prepare the reaction pocket. The artificial design of such an integrated catalytic unit in a non-enzymatic system remains challenging. Molecular imprinting of a supported metal complex provides a promising approach for shape-selective catalysis. In this process, an imprinted cavity with a shape matched to a template molecule is created in a polymer matrix with a catalytically active metal site. In this Account, we review our studies on molecularly imprinted metal complex catalysts, focusing on Ru complexes, on oxide surfaces for shape-selective catalysis. Oxide surface-attached transition metal complex catalysts not only improve thermal stability and catalyst dispersion but also provide unique catalytic performance not observed in homogeneous precursors. We designed molecularly imprinted Ru complexes by using surface-attached Ru complexes with template ligands and inorganic/organic surface matrix overlayers to control the chemical environment around the active metal complex catalysts on oxide surfaces. We prepared the designed, molecularly imprinted Ru complexes on SiO(2) surfaces in a step-by-step manner and characterized them with solid-state (SS) NMR, diffuse-reflectance (DR) UV-vis, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller isotherm (BET), X-ray fluorescence (XRF), and Ru K-edge extended X-ray absorption fine structure (EXAFS). The catalytic performances of these Ru complexes suggest that this process of molecular imprinting facilitates the artificial integration of catalytic functions at surfaces. Further advances such

  17. Reactions of potent antitumor complex trans-[Ru(III)Cl4(indazole)2]- with a DNA-relevant nucleobase and thioethers: insight into biological action.

    Science.gov (United States)

    Egger, Alexander; Arion, Vladimir B; Reisner, Erwin; Cebrián-Losantos, Berta; Shova, Sergiu; Trettenhahn, Günter; Keppler, Bernhard K

    2005-01-10

    Reactions of the complex trans-[RuCl(4)(Hind)(2)](-) (Hind = indazole), which is of clinical relevance today, with both the DNA model nucleobase 9-methyladenine (made) and the thioethers R(2)S (R = Me, Et), as models of the methionine residue in biological molecules possibly acting as nitrogen-competing sulfur-donor ligands for ruthenium atom, have been investigated to get insight into details of mechanism leading to antitumor activity. Three novel ruthenium complexes, viz., [Ru(III)Cl(3)(Hind)(2)(made)], 1, [Ru(II)Cl(2)(Hind)(2)(Me(2)S)(2)], 2, and [Ru(II)Cl(2)(Hind)(2)(Et(2)S)(2)], 3, have been isolated as solids. Oxidation of 2 and 3 with hydrogen peroxide in the presence of 12 M HCl in chloroform afforded the monothioether adducts, viz., [Ru(III)Cl(3)(Hind)(2)(Me(2)S)], 4, and [Ru(III)Cl(3)(Hind)(2)(Et(2)S)], 5. By dissolution of 2 or 3 in DMSO, replacement of both R(2)S ligands by DMSO molecules occurred with isolation of trans,trans,trans-[Ru(II)Cl(2)(Hind)(2)(DMSO)(2)], 6. The products were characterized by elemental analysis, IR, UV-vis, electrospray mass spectrometry, cyclic voltammetry, and X-ray crystallography (1.CH(2)Cl(2).CH(3)OH and 1.1.1H(2)O.0.9CH(3)OH, 2, and 5). The first crystallographic evidence for the monofunctional coordination of the 9-methyladenine ligand to ruthenium via N7 and the self-pairing of the complex molecules via H-bonding, using the usual Watson-Crick pairing donor and acceptor sites of two adjacent 9-methyladenine ligands, is reported. The electrochemical behavior of 1-5 has been studied in DMF and DMSO by cyclic voltammetry. The redox potential values have been interpreted on the basis of the Lever's parametrization method. The E(L) parameter was estimated for 9-methyladenine at 0.18 V, showing that this ligand behaves as a weaker net electron donor than imidazole (E(L) = 0.12 V). The kinetics of the reductively induced stepwise replacement of chlorides by DMF in 4 and 5 were studied by digital simulation of the cyclic

  18. Synthesis and characterization of PdAg as a catalyst for oxygen reduction reaction in acid medium; Sintesis y caracterizacion de PdAg como catalizador para la reaccion de reduccion de oxigeno en medio acido

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Casillas, D. C.; Vazquez-Huerta, G.; Solorza-Feria, O. [Centro de Investigacion y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)]. E-mail: dcmartinez@cinvestav.mx

    2009-09-15

    This work presents the synthesis of the binary compound PdAg and the electrochemical characterization for oxygen reduction reaction (ORR) in acid medium. The catalyst is obtained from the reduction of Pd(NO{sub 3}){sub 2}·2H{sub 2}O and AgNO{sub 3} with NaBH{sub 4} in THF. The synthesized compound was physically characterized with transmission electron microscopy (TEM), sweep electron microscopy (SEM) and x-ray diffraction (XRD) of powder. Electrochemical studies were conducted to determine the catalytic activity and intrinsic properties of the PdAg material for the ORR in acid medium using cyclic voltamperometry (CV), rotary disc electrode (RDE) and electrochemical impedance spectroscopy (EIS) in a solution of H{sub 2}SO{sub 4} 0.5 M at 25 degrees Celsius. The electrochemical current-potential responses were compared to those of palladium and platinum. The kinetic results showed an increase in the performance of the bimetallic electrocatalyst containing Ag as compared to pure Pd, but less than that obtained with nanometric Pt. The Tafel slopes obtained are roughly120 mV dec-1, similar to that reported for Pt and Pd and for other Ru-based electrocatalysts. [Spanish] En este trabajo se presentan la sintesis del compuesto binario PdAg y su caracterizacion electroquimica para la reaccion de reduccion de oxigeno (RRO) en medio acido. El catalizador se obtuvo a partir de la reduccion de Pd(NO{sub 3}){sub 2}·2H{sub 2}O y AgNO{sub 3} con NaBH{sub 4} en THF. El compuesto sintetizado se caracterizo fisicamente por microscopia electronica de transmision (MET), microscopia electronica de barrido (MEB) y difraccion de rayos X (DRX) de polvos. Se realizaron estudios electroquimicos para determinar la actividad catalitica y las propiedades intrinsecas del material de PdAg para la reaccion de reduccion de oxigeno (RRO) en medio acido, utilizando las tecnicas de voltamperometria ciclica (VC), electrodo disco rotatorio (EDR) y espectroscopia de impedancia electroquimica (EIE), en

  19. Three-dimensional magnetic interactions in quasi-two-dimensional PdAs2O6

    Science.gov (United States)

    Zhao, Z. Y.; Wu, Y.; Cao, H. B.; Zhou, H. D.; Yan, J.-Q.

    2017-06-01

    Millimeter-sized PdAs2O6 single crystals are grown using the vapor transport technique. The magnetic order at {{T}\\text{N}}=140 K is studied by measuring magnetic properties, specific heat, and neutron single crystal diffraction. The anisotropic magnetic susceptibility and a metamagnetic transition observed in magnetic fields above 20 kOe suggest that the magnetic moment lies in the ab plane, consistent with the magnetic structure determined by neutron single crystal diffraction. Below 140 K, Pd2+ ions order ferromagnetically in the ab plane but antiferromagnetically along the crystallographic c axis. The ordered moment is refined to be 2.09(2) {μ\\text{B}} /Pd2+ using the fitted magnetic form factor of Pd2+ . A weak λ-type anomaly around T N was observed in specific heat and the magnetic entropy change across T N is 1.72 J mol-1 K.This small entropy change and the temperature dependence of the magnetic susceptibility support the presence of short range correlations in a wide temperature range {{T}\\text{N}} 250 K. The comparison with SrRu2O6 suggests that the magnetic interactions in PdAs2O6 are dominated by Pd-(O-\\text{As}\\text{As} -O)-Pd super-superexchange and three dimensional despite the quasi-two-dimensional arrangement of magnetic ions. The comparison with NiAs2O6 suggests that increasing covalency of isostructural compounds is an effective approach to design and to discover new materials with higher magnetic order temperatures in the localized regime.

  20. Special IR properties of palladium nanoparticles and their aggregations in CO molecular probe infrared spectroscopy

    Institute of Scientific and Technical Information of China (English)

    JIANG Yanxia; CHEN Wei; LIAO Honggang; JIN Lanying; SUN Shigang

    2004-01-01

    Dispersed Pd nanoparticles (Pdn) have been synthesized by reducing H2PdCI4 with ethanol, and stabilized using poly(vinylpyrrolidone) (PYP). The Pdn is applied to the glassy carbon substrate to form a thin film, and then the potential cyclic scanning at 50 mV. S-1 from -0.25 to 1.25 V was carried out for about 30 min to form the aggregations of Pdn (Pdagn). FTIR spectroscopy of both transmission and re flection modes was employed to study CO adsorption on Pdn and Pdagn in both solidlliquid and solidlgas interfaces. It has been revealed that CO adsorption on Pdn film yields two IR bands near 1964 and 1906 cm-1, which are assigned to IR absorption of CO bonded on asymmetric and symmetric bridge sites, respectively. In contrast to the IR properties of CO adsorbed on Pdn, only species of CO bonded on asymmetric bridge sites was determined on Pdang, and the direction of the IR band near 1963 cm-1 is completely inverted.The full width at half-maximum (FWHM) of the COasBs band near 1964 cm-1 is measured to be 14 cm-1 on Pdn film, while it is 24 cm-1 on Pdnag film. The results of the present study demonstrated that the inverting of the IR band direction is a general phenomenon that is closely related to the interaction between nanoparticles in aggregation of Pdn.

  1. Fuel management simulation for CANFLEX-RU in CANDU 6

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Chang Joon; Suk, Ho Chun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    Fuel management simulations have been performed for CANFLEX-09% RU fuel in the CANDU 6 reactor. In this study, the bi-directional 4-bundle shift fuelling scheme was assumed. The lattice cell and time-average calculation were carried out. The refuelling simulation calculations were performed for 600 full power days. Time-averaged results show good axial power profile with the CANFLEX-RU fuel. During the simulation period, the maximum channel and bundle power were maintained below the licensing limit of CANDU 6 reactor. 7 refs., 4 figs. (Author)

  2. Role of steps in N-2 activation on Ru(0001)

    DEFF Research Database (Denmark)

    Dahl, Søren; Logadottir, Ashildur; Egeberg, Rasmus

    1999-01-01

    Using adsorption experiments and density functional calculations we show that N-2 dissociation on the Ru(0001) surface is totally dominated by steps. The measured adsorption rate at the steps is at least 9 orders of magnitude higher than on the terraces at 500 K, and the corresponding calculated ...... difference in activation energy is 1.5 eV. The low barrier at the step is shown to be due to a combination of electronic and geometrical effects. The consequences for Ru as a catalyst for ammonia synthesis are discussed....

  3. Oxidation resistance of Ru-capped EUV multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Bajt, S; Dai, Z; Nelson, E J; Wall, M A; Alameda, J; Nguyen, N; Baker, S; Robinson, J C; Taylor, J S; Clift, M; Aquila, A; Gullikson, E M; Edwards, N G

    2005-02-23

    Differently prepared Ru-capping layers, deposited on Mo/Si EUV multilayers, have been characterized using a suite of metrologies to establish their baseline structural, optical, and surface properties in as-deposited state. Same capping layer structures were tested for their thermal stability and oxidation resistance. Post-mortem characterization identified changes due to accelerated tests. The best performing Ru-capping layer structure was studied in detail with transmission electron microscopy to identify the grain microstructure and texture. This information is essential for modeling and performance optimization of EUVL multilayers.

  4. RuBee and RFID A confidential summary,May 2009

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The letters"RFID"have become a negative to many of our end-customers,so we have had to distance RuBee from the entire category and discourage any attempt to characterize RuBee as just another RFID technology.We never engage in pilots or trials where RFID is seen as a competing technology to RuBee.Most

  5. Potential oscillations in a proton exchange membrane fuel cell with a Pd-Pt/C anode

    Science.gov (United States)

    Lopes, Pietro P.; Ticianelli, Edson A.; Varela, Hamilton

    We report in this paper the occurrence of potential oscillations in a proton exchange membrane fuel cell (PEMFC) with a Pd-Pt/C anode, fed with H 2/100 ppm CO, and operated at 30 °C. We demonstrate that the use of Pd-Pt/C anode enables the emergence of dynamic instabilities in a PEMFC. Oscillations are characterized by the presence of very high oscillation amplitude, ca. 0.8 V, which is almost twice that observed in a PEMFC with a Pt-Ru/C anode under similar conditions. The effects of the H 2/CO flow rate and cell current density on the oscillatory dynamics were investigated and the mechanism rationalized in terms of the CO oxidation and adsorption processes. We also discuss the fundamental aspects concerning the operation of a PEMFC under oscillatory regime in terms of the benefit resulting from the higher average power output.

  6. A ternary tetracoordinated Pd II complex with metformin and dipicolinate: Synthesis, characterization and crystal structure

    Science.gov (United States)

    Moghimi, A.; Khavassi, H. R.; Dashtestani, F.; Kordestani, D.; Ekram Jafari, A.; Maddah, B.; Moosavi, S. M.

    2011-06-01

    A proton transfer compound L, (MetH) 2(dipic), (dipicH 2 = 2,6-pyridinedicarboxylic acid and Met = Metformin (N,N-dimethylebiguanidine), was synthesized and characterized by IR, 1H and 13C NMR spectroscopy. The reaction of L with PdCl 2 in water results in the formation of novel tetracoordinated Pd II complex [Pd(dipic)(Met)]·2H 2O indicating the participation of both dipic 2- and Met as chelating ligands. This complex was characterized by single crystal X-ray analysis. The crystal system is monoclinic with space group P2 1/c. The unit cell dimensions for Pd II complex 1 is a = 8.8619(14) Å, b = 9.5072(9) Å, c = 19.153(3) Å.

  7. Excited states of neutron rich Pd from fragmentation

    Science.gov (United States)

    Hecht, A. A.; Walters, W. B.; Hoteling, N.; Mantica, P. F.; Becerril, A.; Fleckenstein, T.; Lorusso, G.; Pereira, J.; Pinter, J.; Stoker, J.; Quinn, M.

    2007-04-01

    The neutron rich region approaching N=82 and Z=50 is interesting for nuclear structure and nuclear astrophysics, both as a test of the shell closures far from stability and as the path for r-process nucleosynthesis. This region is difficult to access with fusion-evaporation reactions and novel techniques must be used. At the National Superconducting Cyclotron Laboratory (NSCL) an experiment was recently performed by fragmentation of a Xe beam using a Be target to examine isomers and beta decay from these neutron rich nuclei. The radioisotope fragments passed through several Si planar detectors and were implanted in a double-sided Si strip detector (DSSD) in the Beta Counting System (BCS). Fragments were identified via δE and TOF. Particle emitting decays were tracked in several layers of single sided strip detectors following the DSSD, while the SEGA array surrounding the DSSD was used to collect gamma emission following beta and isomer decay. Several neutron rich nuclei were observed in this experiment, including Ru, Rh, Pd, Ag, Cd, and In. Results on Pd will be discussed.

  8. A Renewable and Ultrasensitive Electrochemiluminescence Immunosenor Based on Magnetic RuL@SiO2-Au~RuL-Ab2 Sandwich-Type Nano-Immunocomplexes

    Directory of Open Access Journals (Sweden)

    Ning Gan

    2011-08-01

    Full Text Available An ultrasensitive and renewable electrochemiluminescence (ECL immunosensor was developed for the detection of tumor markers by combining a newly designed trace tag and streptavidin-coated magnetic particles (SCMPs. The trace tag (RuL@SiO2-Au~RuL-Ab2 was prepared by loading Ru(bpy32+(RuL-conjuged secondary antibodies (RuL-Ab2 on RuL@SiO2 (RuL-doped SiO2 doped Au (RuL@SiO2-Au. To fabricate the immunosensor, SCMPs were mixed with biotinylated AFP primary antibody (Biotin-Ab1, AFP, and RuL@SiO2-Au~RuL-Ab2 complexes, then the resulting SCMP/Biotin-Ab1/AFP/RuL@SiO2-Au~RuL-Ab2 (SBAR sandwich-type immunocomplexes were absorbed on screen printed carbon electrode (SPCE for detection. The immunocomplexes can be easily washed away from the surface of the SPCE when the magnetic field was removed, which made the immunosensor reusable. The present immunosensor showed a wide linear range of 0.05–100 ng mL–1 for detecting AFP, with a low detection limit of 0.02 ng mL–1 (defined as S/N = 3. The method takes advantage of three properties of the immunosensor: firstly, the RuL@SiO2-Au~RuL-Ab2 composite exhibited dual amplification since SiO2 could load large amount of reporter molecules (RuL for signal amplification. Gold particles could provide a large active surface to load more reporter molecules (RuL-Ab2. Accordingly, through the ECL response of RuL and tripropylamine (TPA, a strong ECL signal was obtained and an amplification analysis of protein interaction was achieved. Secondly, the sensor is renewable because the sandwich-type immunocomplexes can be readily absorbed or removed on the SPCE’s surface in a magnetic field. Thirdly, the SCMP modified probes can perform the rapid separation and purification of signal antibodies in a magnetic field. Thus, the present immunosensor can simultaneously realize separation, enrichment and determination. It showed potential application for the detection of AFP in human sera.

  9. PD-1 and PD-L1 antibodies for melanoma.

    Science.gov (United States)

    Tsai, Katy K; Zarzoso, Inés; Daud, Adil I

    2014-01-01

    Melanoma is the most serious form of skin cancer. Metastatic melanoma historically carries a poor prognosis and until recently there have been few effective agents available to treat widely disseminated disease. Recognition of the immunogenic nature of melanoma has resulted in the development of various immunotherapeutic approaches, especially with regards to the programmed cell death 1 (PD-1) receptor and its ligand (PD-L1). Antibodies targeting the PD-1 axis have shown enormous potential in the treatment of metastatic melanoma. Here, we will review the immune basis for the disease and discuss approved immunotherapeutic options for advanced melanoma, as well as the current state of development of PD-1 and PD-L1 antibodies and their importance in shaping the future of melanoma treatment.

  10. Highly efficient photocatalytic degradation of methylene blue by PoPD/TiO2 nanocomposite.

    Science.gov (United States)

    Yang, Chuanxi; Zhang, Ming; Dong, Wenping; Cui, Guanwei; Ren, Zongming; Wang, Weiliang

    2017-01-01

    The poly-o-phenylenediamine (PoPD)/TiO2 nanocomposite was successfully synthesized via 'in situ' oxidative polymerization method. The modified photocatalysts were characterized by BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrarad spectra (FT-IR), thermogravimrtic analysis (TGA), X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible diffuse reflectance spectrum (UV-Vis DRS) and Photocurrent Test. The results showed that the PoPD exists on the surface of TiO2, the presence of PoPD does not impact on the lattice structure and grain size of TiO2, and the presence of PoPD enhances the visible response and photoelectric property. The photocatalytic degradation of methylene blue (MB) was chosen as a model reaction to evaluate the photocatalytic activities of TiO2 and PoPD/TiO2. The optimal preparation condition was the molar ratio of oPD to TiO2 = 3:1, HCl concentration = 1.2 mol/L, the molar ratio of APS to oPD = 1:1. The apparent first-order rate constant kapp of PoPD/TiO2 nanocomposite was 0.0098 min-1, which is 6 times higher than TiO2 (0.0016 min-1). Meanwhile, the PoPD/TiO2 nanocomposites showed excellent photocatalytic stability, and the photocatalytic stability was depended on the stability of structure. At last, the photocatalytic mechanism of POPD/TiO2 nanocomposites was also proposed based on the synergetic effect between TiO2 and PoPD.

  11. Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/−-IRS-1+/− Double Heterozygous (IR-IRS1dh Mice

    Directory of Open Access Journals (Sweden)

    Andras Franko

    2017-05-01

    Full Text Available Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR+/−-insulin receptor substrate-1 (IRS-1+/− double heterozygous (IR-IRS1dh mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver.

  12. The Nanostructuring of Atomically Flat Ru(0001) upon Oxidation and Reduction

    Science.gov (United States)

    Goriachko, A.; Over, H.

    2016-12-01

    The O/Ru(0001) system is widely studied due to its rich phase variety of various stoichiometry and atomic arrangements, including the formation of a RuO2/Ru(0001) oxide layer. Apart from homogeneous ruthenium surfaces in certain oxidation states, also strongly heterogeneous surfaces can exist due to oxidation state's variation at the nanoscale. We report on a scanning tunneling microscopy (STM) study of the nanostructuring of the oxidized Ru(0001) surface as a result of its interaction with molecular oxygen at elevated temperatures and subsequent reduction of a resulting RuO2 film by CO or HCl molecules from the gas phase in high-vacuum environment.

  13. STUDY ON POLYMER- Ru- Co BIMETALLIC COMPLEXES CATALYSTS Ⅱ. X-RAY PHOTOELECTRON SPECTROSCOPIC ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    ZONG Huijuan; TANG Qi; CHEN Zonghan; JIANG Yingyan

    1991-01-01

    Polymer-Ru-Co bimetallic complexes have been examined by X-ray photoelectron spectroscopy.The catalyst is highly active only when the mole ratio of Co/Ru is 4:3. The activity of catalysts does not depend on the total Co/Ru ratio, but on the surface stoichiometry of Co and Ru. When the relative intensities of Co2p and Ru3d of XP S peaks are close to each other and both are high, the catalyst exhibits its maximum activity.The mechanism of catalytic hydroformylation has been discussed.

  14. Beta decay of {sup 111}Tc to {sup 111}Ru

    Energy Technology Data Exchange (ETDEWEB)

    Pfeiffer, B.; Kloeckl, I.; Kratz, K.L. [Mainz Univ. (Germany). Inst. fuer Kernchemie; Lhersonneauc, G.; Dendooven, P.; Honkanen, A.; Huhta, M.; Oinonen, M.; Penttilae, H.; Peraejaervi, K.; Wang, J.C.; Aeystoe, J. [Department of Physics, University of Jyvaeskylae, P.O.Box 35, FIN-40351 Jyvaeskylae (Finland); Persson, J.R. [School of Physics and Space Research, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    1998-05-01

    The {beta}-decay of the very neutron-rich {sup 111}Tc nucleus has been observed. A partial decay scheme of {sup 111}Ru is presented, complementing the high-spin levels earlier reported in spontaneous fission work. (orig.) With 1 fig., 2 tabs., 20 refs.

  15. Väike Hüüru ja suur Laagri

    Index Scriptorium Estoniae

    Nirk, Lia

    2016-01-01

    Laagri keskuses asuva Saue vallaraamatukogu ning Hüüru külaseltsi vahel sõlmiti 2014. a. raamleping, mille alusel vallaraamatukogu maksab külaseltsile raamatukoguteenuse osutamise eest ja raamatukoguhoidjaks on MTÜ palgatud kultuuritöötaja

  16. Registration of 'RU9101001'/'Katy' recombinant inbred lines of rice

    Science.gov (United States)

    The cross of RU9101001/'Katy' rice (Oryza sativa L.) was used to develop a mapping population consisting of 238 F9 generation recombinant inbred lines of rice (Oryza sativa L.) (GSOR100361 to GSOR100600). This population has been used to map major genes that provide resistance to the rice blast pat...

  17. Photoacoustic characterization of n-RuSe2 semiconductor pellets

    Science.gov (United States)

    Bernal-Alvarado, J.; Vargas-Luna, M.; Solorza-Feria, O.; Mondragón, R.; Alonso-Vante, N.

    2000-09-01

    Using the open photoacoustic cell technique, a set of physical properties for a semiconductor (n-RuSe2) in powder form was measured. According to the Dramicanin theoretical model, charge carriers transport parameters (bulk and surface) and the effective thermal diffusivity were obtained.

  18. Hydrogen mediated transport of Sn to Ru film surface

    NARCIS (Netherlands)

    Faradzhev, N.; Sidorkin, V.

    2009-01-01

    The authors report on the interaction of atomic hydrogen with Sn and thin Ru film at room temperature. The study is done using a combination of photoelectron and low energy ion scattering spectroscopies as well as scanning electron microscopy. The adsorption of hydrogen on a Sn surface leads to the

  19. Hydrogen mediated transport of Sn to Ru film surface

    NARCIS (Netherlands)

    Faradzhev, N.; Sidorkin, V.

    2009-01-01

    The authors report on the interaction of atomic hydrogen with Sn and thin Ru film at room temperature. The study is done using a combination of photoelectron and low energy ion scattering spectroscopies as well as scanning electron microscopy. The adsorption of hydrogen on a Sn surface leads to the

  20. Dissociation of CH4 on Ni(111) and Ru(0001)

    DEFF Research Database (Denmark)

    Egeberg, Rasmus; Ullmann, S.; Alstrup, I.;

    2002-01-01

    the steps were passivated with Au. On Ni(111) sputtering the surface at 500 K with no subsequent annealing increased the initial sticking but at higher coverages this effect vanished. We interpret these results as due to the steps on both surfaces being blocked by carbon species leaving them inaccessible...... to impinging CH4 molecules. We conclude that in these types of experiments steps play a minor role for CH4 dissociation on Ru(0 0 0 1) and Ni(l 1 1). In a temperature programmed oxidation reaction we observe that carbon from the steps of Ru(0 0 0 1) leaves the surface at lower temperatures than carbon from...... the terraces, Finally we have observed a large promotion of the sticking probability of CH4 on Ru(0 0 0 1) by increasing the surface temperature at a fixed gas temperature thus lending support to a mechanism where the dissociation of methane takes place over Ru atoms displaced normal to the surface....

  1. Chemical fingerprinting of algaenans using RuO4 degradation

    NARCIS (Netherlands)

    Blokker, P.; Ende, H. van den; Leeuw, J.W. de; Versteegh, G.J.M.; Sinninghe Damsté, J.S.

    2006-01-01

    The freshwater green microalgae, Oocystus solitaria Wittrock f. maior Wille, Pediastrum braunii Wartmann, Pediastrum kawraiskyi Schmidle, Sorastrum spinulosum Na¨geli and Coelastrum reticulatum (Dangeard) Senn were investigated with respect to the presence of algaenan and the corresponding RuO4 chem

  2. Photoinduced energy- and electron-transfer processes in dinuclear Ru(II)-Os(II), Ru(II)-Os(III), and Ru(III)-Os(II) trisbipyridine complexes containing a shape-persistent macrocyclic spacer.

    Science.gov (United States)

    Venturi, Margherita; Marchioni, Filippo; Ferrer Ribera, Belén; Balzani, Vincenzo; Opris, Dorina M; Schlüter, A Dieter

    2006-01-16

    The PF6- salt of the dinuclear [(bpy)2Ru(1)Os(bpy)2]4+ complex, where 1 is a phenylacetylene macrocycle which incorporates two 2,2'-bipyridine (bpy) chelating units in opposite sites of its shape-persistent structure, was prepared. In acetonitrile solution, the Ru- and Os-based units display their characteristic absorption spectra and electrochemical properties as in the parent homodinuclear compounds. The luminescence spectrum, however, shows that the emission band of the Ru(II) unit is almost completely quenched with concomitant sensitization of the emission of the Os(II) unit. Electronic energy transfer from the Ru(II) to the Os(II) unit takes place by two distinct processes (k(en) = 2.0x10(8) and 2.2x10(7) s(-1) at 298 K). Oxidation of the Os(II) unit of [(bpy)2Ru(1)Os(bpy)2]4+ by Ce(IV) or nitric acid leads quantitatively to the [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ complex which exhibits a bpy-to-Os(III) charge-transfer band at 720 nm (epsilon(max) = 250 M(-1) cm(-1)). Light excitation of the Ru(II) unit of [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ is followed by electron transfer from the Ru(II) to the Os(III) unit (k(el,f) = 1.6x10(8) and 2.7x10(7) s(-1)), resulting in the transient formation of the [(bpy)2Ru(III)(1)Os(II)(bpy)2]5+ complex. The latter species relaxes to the [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ one by back electron transfer (k(el,b) = 9.1x10(7) and 1.2x10(7) s(-1)). The biexponential decays of the [(bpy)2*Ru(II)(1)Os(II)(bpy)2]4+, [(bpy)2*Ru(II)(1)Os(III)(bpy)2]5+, and [(bpy)2Ru(III)(1)Os(II)(bpy)2]5+ species are related to the presence of two conformers, as expected because of the steric hindrance between hydrogen atoms of the pyridine and phenyl rings. Comparison of the results obtained with those previously reported for other Ru-Os polypyridine complexes shows that the macrocyclic ligand 1 is a relatively poor conducting bridge.

  3. #Occupy IR: Exposing the Orthodoxy

    OpenAIRE

    Ivan Manokha; Mona Chalabi

    2012-01-01

    The #occupy IR/IPE initiative was created in response to the #occupy movement, whose own roots can be traced backed to the latest crisis of global finance. In this contribution, we link #occupy and the crisis in a different way. We argue that we must occupy IR/IPE because of the discipline’s failure to apprehend and acknowledge the crisis itself, just as the Occupy movement is calling for their overarching authorities to notice and help address the social and economic inequalities produced by...

  4. Rethinking IR from the Amazon

    Directory of Open Access Journals (Sweden)

    Manuela Picq

    Full Text Available Abstract This article proposes Amazonia as a site to think world politics. The Amazon is invisible in the study International Relations (IR, yet its experiences are deeply global. I present the international dynamics at play in Amazonia at different historical moments to posit that this periphery has contributed to forging the political-economy of what is refer to as the core. The Amazon's absence from the study of IR speaks about the larger inequality in processes of knowledge production. Serious engagements with Amazonia are one way to invite a plurality of worlds in the production of theories, disrupting global divisions of labor in knowledge production ally.

  5. Ophthalmologic Baseline Characteristics and 2-Year Ophthalmologic Safety Profile of Pramipexole IR Compared with Ropinirole IR in Patients with Early Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    William Seiple

    2016-01-01

    Full Text Available Background. Parkinson’s disease (PD progressively affects dopaminergic neurotransmission and may affect retinal dopaminergic functions and structures. Objective. This 2-year randomized, open-label, parallel-group, flexible-dose study, NCT00144300, evaluated ophthalmologic safety profiles of immediate-release (IR pramipexole and ropinirole in patients with early idiopathic PD with ≤6 months’ prior dopamine agonist exposure and without preexisting major eye disorders. Methods. Patients received labeled IR regimens of pramipexole (n=121 or ropinirole (n=125 for 2 years. Comprehensive ophthalmologic assessments (COA included corrected acuity, Roth 28-color test, slit-lamp biomicroscopy, intraocular pressure, computerized visual field test, fundus photography, and electroretinography. Results. At baseline, we observed retinal pigmentary epithelium (RPE hypopigmentation not previously reported in PD patients. The estimated relative risk of 2-year COA worsening with pramipexole versus ropinirole was 1.07 (95% CI: 0.71–1.60. Mean changes from baseline in Unified Parkinson’s Disease Rating System parts II+III total scores (pramipexole: 1 year, −4.1±8.9, and 2 years, −0.7±10.1, and ropinirole: 1 year, −3.7±8.2, and 2 years, −1.7±10.5 and Hoehn–Yahr stage distribution showed therapeutic effects on PD symptoms. Safety profiles were consistent with labeling. Conclusions. The risk of retinal deterioration did not differ in early idiopathic PD patients receiving pramipexole versus ropinirole. RPE hypopigmentation at baseline was not previously reported in this population. This trial is registered with NCT00144300.

  6. Ophthalmologic Baseline Characteristics and 2-Year Ophthalmologic Safety Profile of Pramipexole IR Compared with Ropinirole IR in Patients with Early Parkinson's Disease

    Science.gov (United States)

    Jennings, Danna; Borchert, Leona; Canale, Lee; Fagan, Nora

    2016-01-01

    Background. Parkinson's disease (PD) progressively affects dopaminergic neurotransmission and may affect retinal dopaminergic functions and structures. Objective. This 2-year randomized, open-label, parallel-group, flexible-dose study, NCT00144300, evaluated ophthalmologic safety profiles of immediate-release (IR) pramipexole and ropinirole in patients with early idiopathic PD with ≤6 months' prior dopamine agonist exposure and without preexisting major eye disorders. Methods. Patients received labeled IR regimens of pramipexole (n = 121) or ropinirole (n = 125) for 2 years. Comprehensive ophthalmologic assessments (COA) included corrected acuity, Roth 28-color test, slit-lamp biomicroscopy, intraocular pressure, computerized visual field test, fundus photography, and electroretinography. Results. At baseline, we observed retinal pigmentary epithelium (RPE) hypopigmentation not previously reported in PD patients. The estimated relative risk of 2-year COA worsening with pramipexole versus ropinirole was 1.07 (95% CI: 0.71–1.60). Mean changes from baseline in Unified Parkinson's Disease Rating System parts II+III total scores (pramipexole: 1 year, −4.1 ± 8.9, and 2 years, −0.7 ± 10.1, and ropinirole: 1 year, −3.7 ± 8.2, and 2 years, −1.7 ± 10.5) and Hoehn–Yahr stage distribution showed therapeutic effects on PD symptoms. Safety profiles were consistent with labeling. Conclusions. The risk of retinal deterioration did not differ in early idiopathic PD patients receiving pramipexole versus ropinirole. RPE hypopigmentation at baseline was not previously reported in this population. This trial is registered with NCT00144300. PMID:28078162

  7. Spectroscopic, Electrochemical and Computational Characterisation of Ru Species Involved in Catalytic Water Oxidation: Evidence for a [RuV(O)(Py2Metacn)] Intermediate

    OpenAIRE

    Casadevall, Carla; Codolà Duch, Zoel; Costas Salgueiro, Miquel; Lloret Fillol, Julio

    2016-01-01

    A new family of ruthenium complexes based on the N-pentadentate ligand Py2Metacn (N-methyl-N′,N′′-bis(2-picolyl)-1,4,7-triazacyclononane) has been synthesised and its catalytic activity has been studied in the water-oxidation (WO) reaction. We have used chemical oxidants (ceric ammonium nitrate and NaIO4) to generate the WO intermediates [RuII(OH2)(Py2Metacn)]2+, [RuIII(OH2)(Py2Metacn)]3+, [RuIII(OH)(Py2Metacn)]2+ and [RuIV(O)(Py2Metacn)]2+, which have been characterised spectroscopically. Th...

  8. Mechanism of -O-O- bond activation and catalysis by RuIII-pac complexes (pac = polyaminocarboxylate)

    Indian Academy of Sciences (India)

    Debabrata Chatterjee

    2012-11-01

    This paper presents the mechanistic aspects of the -O-O- bond activation by the Ru-pac (pac = polyaminocarboxylate) complex leading to the formation of various catalytic active species, viz. [RuIII(pac)(OOH)]2−, [RuIV(pac)(OH)]− and [RuV(pac)(O)]−, and their reactivity towards oxidation of a few organic compounds.

  9. Mechanism of RuO2 crystallization in borosilicate glass: an original in situ ESEM approach.

    Science.gov (United States)

    Boucetta, Hassiba; Podor, Renaud; Stievano, Lorenzo; Ravaux, Johann; Carrier, Xavier; Casale, Sandra; Gossé, Stéphane; Monteiro, Amélie; Schuller, Sophie

    2012-03-19

    Ruthenium, a fission product arising from the reprocessing of spent uranium oxide (UOX) fuel, crystallizes in the form of acicular RuO(2) particles in high-level waste containment glass matrices. These particles are responsible for significant modifications in the physicochemical behavior of the glass in the liquid state, and their formation mechanisms are a subject of investigation. The chemical reactions responsible for the crystallization of RuO(2) particles with acicular or polyhedral shape in simplified radioactive waste containment glass are described. In situ high-temperature environmental scanning electron microscopy (ESEM) is used to follow changes in morphology and composition of the ruthenium compounds formed by reactions at high temperature between a simplified RuO(2)-NaNO(3) precursor and a sodium borosilicate glass (SiO(2)-B(2)O(3)-Na(2)O). The key parameter in the formation of acicular or polyhedral RuO(2) crystals is the chemistry of the ruthenium compound under oxidized conditions (Ru(IV), Ru(V)). The precipitation of needle-shaped RuO(2) crystals in the melt might be associated with the formation of an intermediate Ru compound (Na(3)Ru(V)O(4)) before dissolution in the melt, allowing Ru concentration gradients. The formation of polyhedral crystals is the result of the direct incorporation of RuO(2) crystals in the melt followed by an Ostwald ripening mechanism.

  10. Substrate-mediated enhanced activity of Ru nanoparticles in catalytic hydrogenation of benzene

    KAUST Repository

    Liu, Xin

    2012-01-01

    The impact of carbon substrate-Ru nanoparticle interactions on benzene and hydrogen adsorption that is directly related to the performance in catalytic hydrogenation of benzene has been investigated by first-principles based calculations. The stability of Ru 13 nanoparticles is enhanced by the defective graphene substrate due to the hybridization between the dsp states of the Ru 13 particle with the sp 2 dangling bonds at the defect sites. The local curvature formed at the interface will also raise the Ru atomic diffusion barrier, and prohibit the particle sintering. The strong interfacial interaction results in the shift of averaged d-band center of the deposited Ru nanoparticle, from -1.41 eV for a freestanding Ru 13 particle, to -1.17 eV for the Ru/Graphene composites, and to -1.54 eV on mesocellular foam carbon. Accordingly, the adsorption energies of benzene are increased from -2.53 eV for the Ru/mesocellular foam carbon composites, to -2.62 eV on freestanding Ru 13 particles, to -2.74 eV on Ru/graphene composites. A similar change in hydrogen adsorption is also observed, and all these can be correlated to the shift of the d-band center of the nanoparticle. Thus, Ru nanoparticles graphene composites are expected to exhibit both high stability and superior catalytic performance in hydrogenation of arenes. © 2012 The Royal Society of Chemistry.

  11. Electronic structures and vibrational properties of coronene on Ru(0001): first-principles study

    Institute of Scientific and Technical Information of China (English)

    Zhang Yu-Yang; Du Shi-Xuan; Gao Hong-Jun

    2012-01-01

    We calculate the configurations,electronic structures,vibrational properties at the coronene/Ru(0001) interface,and adsorption of a single Pt atom on coronene/Ru(0001) based on density functional theory calculations.The geometric structures and electronic structures of the coronene on Ru(0001) are compared with those of the graphene/Ru(0001).The results show that the coronene/Ru(0001) can be a simplified model system used to describe the interaction between graphene and ruthenium.Further calculations of the vibrational properties of coronene molecule adsorbed on Ru(0001)suggest that the phonon properties of differently corrugated regions of graphene on Ru(0001) are different.This model system is also used to investigate the selective adsorption of Pt atoms on graphene/Ru(0001).The configurations of Pt on coronene/Ru(0001) with the lowest binding energy give clues to explain the experimental observation that a Pt cluster selectively adsorbs on the second highest regions of graphene/Ru(0001).This work provides a simple model for understanding the adsorption properties and vibrational properties of graphene on Ru(0001) substrate.

  12. Spatial scanning spectroelectrochemistry. Study of the electrodeposition of Pd nanoparticles at the liquid/liquid interface.

    Science.gov (United States)

    Izquierdo, Daniel; Martinez, Alberto; Heras, Aranzazu; Lopez-Palacios, Jesus; Ruiz, Virginia; Dryfe, Robert A W; Colina, Alvaro

    2012-07-03

    Spatial scanning spectroelectrochemistry is a new analytical technique that provides spectral information at different distances from an electrified liquid/liquid interface where an electrochemical process takes place. As a proof of concept, we have studied two different electrochemical processes at the electrified liquid/liquid interface: (1) Ru(bpy)(3)(2+) transfer through the water/1,2-dichloroethane interface and (2) electrodeposition of Pd nanoparticles at the water/1,2-dichloroethane interface. The instrumental setup developed consists of a movable slit for the light beam to sample at well-defined positions on both sides of the interface, providing important information about the chemical process occurring. If the slit is scanned at different distances from the interface during an electrochemical experiment, a complete picture of the reactions and equilibria in the diffusion layer can be obtained. For example, in the case of the Ru(bpy)(3)(2+), the experiments show clearly how the complex is transferred from one phase to the other. In the case of electrosynthesis of Pd nanoparticles, it is demonstrated that nanoparticles are not only deposited at the interface but diffuse to the aqueous bulk solution. These in situ observations were confirmed by ex situ experiments using transmission electron microscopy.

  13. Atomic layer deposition of Ru from CpRu(CO)(2)Et using O-2 gas and O-2 plasma

    NARCIS (Netherlands)

    Leick, N.; Verkuijlen, R. O. F.; Lamagna, L.; Langereis, E.; Rushworth, S.; Roozeboom, F.; M. C. M. van de Sanden,; Kessels, W. M. M.

    2011-01-01

    The metalorganic precursor cyclopentadienylethyl(dicarbonyl)ruthenium (CpRu(CO)(2)Et) was used to develop an atomic layer deposition (ALD) process for ruthenium. O-2 gas and O-2 plasma were employed as reactants. For both processes, thermal and plasma-assisted ALD, a relatively high growth-per-cycle

  14. Laser-Induced Fluorescence Spectroscopy of Two Ruthenium-Bearing Molecules: RuF and RuCl

    Science.gov (United States)

    Zarringhalam, Hanif; Adam, Allan G.; Linton, Colan; Tokaryk, Dennis W.

    2017-06-01

    This work extends the electronic spectroscopy of RuF, and reports on what we believe is the first observation of RuCl. Both molecules have been created in a laser-ablation molecular beam apparatus at UNB, and their spectra have been detected by laser-induced fluorescence. In the low-resolution survey of RuF from 400 to 770 nm, five bands were detected in the blue, green and infrared regions of the electromagnetic spectrum. Four of them were rotationally analyzed from high-resolution data. The three bands in the green region are associated with the ^4Γ_{11/2}-X^4Φ_{9/2} system first observed by Steimle et al. A new ^4Δ_{7/2}-X^4Φ_{9/2} transition in the blue region was also detected. Two high-resolution bands of RuCl were rotationally analyzed, and the ground state was also found to be X^4Φ_{9/2}. The data provide detailed structural information about the molecules, such as bond lengths, vibrational frequencies, isotopic structure, spin-orbit interactions and hyperfine interactions. T. C. Steimle, W. Virgo and T. Ma, J. Chem. Phys. 124 024309 (2006).

  15. Methanol electro-oxidation on Pt-Ru-P/C and Pt-Ru-P/MWCNT in acidic medium

    CSIR Research Space (South Africa)

    Modibedi, M

    2009-06-01

    Full Text Available Pt-Ru-P was prepared by the chemical reduction method using sodium hypophoshite as a reducing agent on Vulcan XC 72 and multi-walled carbon nano-tubes (MWCNTs). Sodium citrate was added as the stabilizer during electro-catalyst preparation...

  16. Structural investigations in BaFe(2-x)Ru(x)As2 as a function of Ru and temperature.

    Science.gov (United States)

    Sharma, Shilpam; Bharathi, A; Vinod, K; Sundar, C S; Srihari, V; Sen, Smritijit; Ghosh, Haranath; Sinha, Anil K; Deb, S K

    2015-02-01

    We present the results of synchrotron X-ray diffraction (XRD) measurements on powdered single-crystal samples of BaFe(2-x)Ru(x)As2, as a function of Ru content, and as a function of temperature, across the spin-density wave transition in BaFe(1.9)Ru(0.1)As2. The Rietveld refinements reveal that with Ru substitution, while the a-axis increases, the c-axis decreases. In addition, the variation of positional coordinates of As (z(As)), the Fe-As bond length and the As-Fe-As bond angles have also been determined. In the sample with x = 0.1, temperature-dependent XRD measurements indicate that the orthorhombicity shows the characteristic increase with a decrease in temperature, below the magnetic transition. It is seen that the c-axis, the As-Fe-As bond angles, Fe-As bond length and positional coordinates of the As show definite anomalies close to the structural transition. The observed anomalies in structural parameters are analysed in conjunction with restricted geometric optimization of the structure using ab initio electronic structure calculations.

  17. 具夹心结构(Bu4N)7H3[Ru2O(H2O)2(γ-SiW10O36)2]的合成及表征%Studies on the Synthesis and Characterization of Sandwich Type Polyoxometalate (Bu4N)7H3[Ru2O(H2O)2(γ-SiW10O36)2]

    Institute of Scientific and Technical Information of China (English)

    许静玉; 李培; 林欣荣; 李明星; 金松林; 谢高阳; 孙文梁

    2001-01-01

    以γ-[SiW10O36]8-及桥联的K4Ru2OCl10为原料,合成了(Bu4N)7H3[Ru2O(H2O)2(γ-SiW10O36)2],经红外光谱、电子光谱、顺磁共振、磁化率、循环伏安和核磁共振等的表征,证明标题化合物为两聚夹心结构. 其中,γ-[SiW10O36]8-结构保持不变,填入的Ru—O—Ru为直线型,均保持了原料的基本构型.%A di-ruthenium cluster substituted polyoxometalates(Bu4N)7H3[Ru2O(H2O)2(γ-SiW10O36)2] was synthesized by using γ-[SiW10O36]8- and K4Ru2OCl10 as precursors. Several methods (including IR, UV, EPR, magnetic moment measurement, CV and 183W NMR) were used to determine the purity and structure of the title compound. IR, UV data confirmed the purity, the maintenance of the γ-type structure and the substitution of the di-ruthenium cluster; the data of UV, EPR and magnetic moment measurement ensured that the linear structure of K4Ru2OCl10 is still kept; CV and 183W NMR data determined the C2h symmetry sandwich structure of the title compound.

  18. Automated direct assay system for RU38486, an antiprogesterone-antiglucocorticoid agent, and its metabolites using high performance liquid chromatography.

    Directory of Open Access Journals (Sweden)

    Nagoshi,Kazusuke

    1991-04-01

    Full Text Available An automated direct assay system using high performance liquid chromatography was developed for the measurement of RU38486 and its three metabolites (RU42698, RU42848, RU42633 in human serum. Serum concentrations of these compounds were measured up to 144 h following single oral administration of 200 (200 mg group, n = 3 or 400 mg (400 mg group, n = 3 of RU38486 to healthy female volunteers. The serum half-lives (200 mg group-400 mg group of RU38486, RU42698, RU42848 and RU42633 were 31.8-33.1 h, 41.2-39.3 h, 33.9-36.6 h and 29.2-36.6 h, respectively. Our system could quantify them easily and simultaneously, and was considered to be valuable in studies on the relationship between the pharmacokinetics and the clinical effects of RU38486.

  19. A Molybdenum(0) Isocyanide Analogue of Ru(2,2'-Bipyridine)3 (2+) : A Strong Reductant for Photoredox Catalysis.

    Science.gov (United States)

    Büldt, Laura A; Guo, Xingwei; Prescimone, Alessandro; Wenger, Oliver S

    2016-09-05

    We report the first homoleptic Mo(0) complex with bidentate isocyanide ligands, which exhibits metal-to-ligand charge transfer ((3) MLCT) luminescence with quantum yields and lifetimes similar to Ru(bpy)3 (2+) (bpy=2,2'-bipyridine). This Mo(0) complex is a very strong photoreductant, which manifests in its capability to reduce acetophenone with essentially diffusion-limited kinetics as shown by time-resolved laser spectroscopy. The application potential of this complex for photoredox catalysis was demonstrated by the rearrangement of an acyl cyclopropane to a 2,3-dihydrofuran, which is a reaction that requires a reduction potential so negative that even the well-known and strongly reducing Ir(2-phenylpyridine)3 photosensitizer cannot catalyze it. Our study thus provides the proof-of-concept for the use of chelating isocyanides to obtain Mo(0) complexes with long-lived (3) MLCT excited states that are applicable to unusually challenging photoredox chemistry.

  20. Luminescent Behavior of Ru(II) Polypyridyl Morpholine Complexes, Synthesis, Characterization, DNA, Protein Binding, Sensor Effect of Ions/Solvents and Docking Studies.

    Science.gov (United States)

    Vuradi, Ravi Kumar; Putta, Venkat Reddy; Nancherla, Deepika; Sirasani, Satyanarayana

    2016-03-01

    New three ruthenium (II) polypyridyl complexes [Ru(phen)2mpip](2+)(1) {mpip = 2-(4-morpholinophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline}, (phen = 1,10-Phenanthrolene), [Ru(bpy)2mpip](2+)(2) (bpy = 2,2'bipyridyl), [Ru(dmb)2mpip](2+)(3) (dmb = 4, 4-dimethyl 2, 2'-bipyridine) have been synthesized and characterized by spectral studies IR, UV-vis, (1)H, (13)C-NMR, mass and elemental analysis. The binding properties of these three complexes towards calf-thymus DNA (CT-DNA) have been investigated by UV-Vis spectroscopy, different fluorescence methods and viscosity measurements, indicating that all the complexes bind to CT-DNA by means of intercalation, but with different binding affinities. Sensor effect of ions/solvents and BSA (Bovine Serum Albumin) binding studies of these complexes were also studied. Docking studies also reveals that complexes will bind in between base pairs (Intercalate) of DNA and gives information about the binding strength.

  1. Synthesis, characterization and biological activities of some Ru(II) complexes with substituted chalcones and their applications as chemotherapeutics against breast cancer

    Science.gov (United States)

    Singh, Ashok K.; Saxena, Gunjan; Dixit, Shivani; Hamidullah; Singh, Sachin K.; Singh, Sudheer K.; Arshad, M.; Konwar, Rituraj

    2016-05-01

    Four new Ru(II) DMSO complexes with substituted chalcone ligands viz. (E)-1-(2-hydroxyphenyl)-3-(4-methoxyphenyl)prop-2-en-1-one (HL1), (E)-1-(2-hydroxyphenyl)-3-(4-nitrophenyl)prop-2-en-1-one (HL2), (E)-3-(4-(dimethylamino)phenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (HL3) and (E)-1-(2-hydroxyphenyl)-3-(4-Chlorophenyl)prop-2-en-1-one (HL4) have been synthesized, and characterized by micro-analyses, IR, 1H NMR, UV-Vis and ESI-MS and screened for anti-cancer activity against breast cancer cell lines (MCF-7 and MDA MB-231). Compounds HL4 and [Ru(HL1) (O-DMSO)3(S-DMSO)]Cl (M1R) showed significant anti-breast cancer activity as evident from cytotoxicity, morphological and nuclear changes, DNA fragmentation and cell cycle arrest in breast cancer cells. UV-Vis and CD-spectra analysis showed HL4 and M1R interfered with DNA absorption spectra possibly due to DNA binding whereas these compounds were devoid of DNA topoisomerase inhibiting activity. Thus, these Ru(II) compounds have been established as new leads for future optimization by improving anti-cancer potency and safety.

  2. CO-induced Pd segregation and the effect of subsurface Pd on CO adsorption on CuPd surfaces

    Science.gov (United States)

    Padama, A. A. B.; Villaos, R. A. B.; Albia, J. R.; Diño, W. A.; Nakanishi, H.; Kasai, H.

    2017-01-01

    We report results of our study on the adsorption of CO on CuPd surfaces with bulk stoichiometric and nonstoichiometric layers using density functional theory (DFT). We found that the presence of Pd atoms in the subsurface layer promotes the adsorption of CO. We also observed CO-induced Pd segregation on the CuPd surface and we attribute this to the strong CO-Pd interaction. Lastly, we showed that the adsorption of CO promotes Pd-Pd interaction as compared to the pristine surface which promotes strong Cu-Pd interaction. These results indicate that CO adsorption on CuPd surfaces can be tuned by taking advantage of the CO-induced segregation and by considering the role of subsurface Pd atoms.

  3. Anti-PD-L1 atezolizumab-Induced Autoimmune Diabetes: a Case Report and Review of the Literature.

    Science.gov (United States)

    Hickmott, Laura; De La Peña, Hugo; Turner, Helen; Ahmed, Fathelrahman; Protheroe, Andrew; Grossman, Ashley; Gupta, Avinash

    2017-03-02

    Programmed cell death-1 and programmed death ligand 1 (PD-1/PD-L1) inhibitors trigger an immune-mediated anti-tumour response by promoting the activation of cytotoxic T lymphocytes. Although proven to be highly effective in the treatment of several malignancies they can induce significant immune-related adverse events (irAEs) including endocrinopathies, most commonly hypophysitis and thyroid dysfunction, and rarely autoimmune diabetes. Here we present the first case report of a patient with a primary diagnosis of urothelial cancer developing PD-L1 inhibitor-induced autoimmune diabetes. A euglycemic 57 year old male presented to clinic with dehydration after the fifth cycle of treatment with the novel PD-L1 inhibitor atezolizumab. Blood tests demonstrated rapid onset hyperglycaemia (BM 24 mmol/L), ketosis and a low C-peptide level (0.65 ng/mL) confirming the diagnosis of type 1 diabetes. He responded well to insulin therapy and was discharged with stable blood glucose levels. Due to the widening use of PD-1/PD-L1 inhibitors in cancer treatment clinicians need to be aware of this rare yet treatable irAE. Given the morbidity and mortality associated with undiagnosed autoimmune diabetes we recommend routine HbA1c and plasma glucose testing in all patients prior to and during treatment with PD-1/PD-L1 inhibitors until more evidence has accumulated on identifying those patients with a pre-treatment risk of such irAEs.

  4. Pd nanoparticles formation inside porous polymeric scaffolds followed by in situ XANES/SAXS

    Science.gov (United States)

    Longo, A.; Lamberti, C.; Agostini, G.; Borfecchia, E.; Lazzarini, A.; Liu, W.; Giannici, F.; Portale, G.; Groppo, E.

    2016-05-01

    Simultaneous time-resolved SAXS and XANES techniques were employed to follow in situ the formation of Pd nanoparticles from palladium acetate precursor in two porous polymeric supports: polystyrene (PS) and poly(4-vinyl-pyridine) (P4VP). In this study we have investigated the effect of the use of different reducing agents (H2 and CO) from the gas phase. These results, in conjunction with data obtained by diffuse reflectance IR (DRIFT) spectroscopy and TEM measurements, allowed us to unravel the different roles played by gaseous H2 and CO in the formation of the Pd nanoparticles for both PS and P4VP hosting scaffolds.

  5. Shaped Ir-Ni bimetallic nanoparticles for minimizing Ir utilization in oxygen evolution reaction.

    Science.gov (United States)

    Lim, Jinkyu; Yang, Sungeun; Kim, Chanyeon; Roh, Chi-Woo; Kwon, Yongwoo; Kim, Yong-Tae; Lee, Hyunjoo

    2016-04-25

    Shaped Ir-Ni bimetallic nanoparticles were synthesized and used for electrocatalytic oxygen evolution reaction (OER). The obtained bimetallic nanoparticles showed significantly enhanced Ir mass activity and durability compared with Ir nanoparticles.

  6. Methanol Electro-Oxidation on Pt-Ru Alloy Nanoparticles Supported on Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Yangchuan Xing

    2009-09-01

    Full Text Available Carbon nanotubes (CNTs have been investigated in recent years as a catalyst support for proton exchange membrane fuel cells. Improved catalyst activities were observed and attributed to metal-support interactions. We report a study on the kinetics of methanol electro-oxidation on CNT supported Pt-Ru alloy nanoparticles. Alloy catalysts with different compositions, Pt53Ru47/CNT, Pt69Ru31/CNT and Pt77Ru23/CNT, were prepared and investigated in detail. Experiments were conducted at various temperatures, electrode potentials, and methanol concentrations. It was found that the reaction order of methanol electro-oxidation on the PtRu/CNT catalysts was consistent with what has been reported for PtRu alloys with a value of 0.5 in methanol concentrations. However, the electro-oxidation reaction on the PtRu/CNT catalysts displayed much lower activation energies than that on the Pt-Ru alloy catalysts unsupported or supported on carbon black (PtRu/CB. This study provides an overall kinetic evaluation of the PtRu/CNT catalysts and further demonstrates the beneficial role of CNTs.

  7. Growth of Pd{sub 4}S, PdS and PdS{sub 2} films by controlled sulfurization of sputtered Pd on native oxide of Si

    Energy Technology Data Exchange (ETDEWEB)

    Bhatt, R., E-mail: rbhatt@barc.gov.in [Technical Physics Division, Bhabha Atomic Research Center, Mumbai–400 085 (India); Bhattacharya, S.; Basu, R.; Singh, A. [Technical Physics Division, Bhabha Atomic Research Center, Mumbai–400 085 (India); Deshpande, U. [UGC–DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore–452017 (India); Surger, C. [Karlsruhe Institute of Technology, Physikalisches Institut and DFG Center for Functional Nanostructures, P.O. Box 6980, D–76049 Karlsruhe (Germany); Basu, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400 085 (India); Aswal, D.K.; Gupta, S.K. [Technical Physics Division, Bhabha Atomic Research Center, Mumbai–400 085 (India)

    2013-07-31

    Thin films of different Pd–S phase, namely Pd{sub 4}S, PdS and PdS{sub 2}, have been reproducibly grown by the sulfurization of Pd films deposited on native oxide of (111) Si substrates by radio frequency sputtering method. In order to achieve controlled sulfurization, a three-stage sulfurization setup consisting of evaporation chamber, activation chamber and sulfurization chamber has been developed. The sulfurization of Pd films (kept at a constant temperature of 500 °C) was carried out using sulfur vapors activated to different temperature between 550 and 700 °C. The results of X-ray diffraction and X-ray photoelectron spectroscopy measurements show that formation of Pd{sub 4}S, PdS and PdS{sub 2} phases takes place for the activation temperatures of 550, 600 and 700 °C, respectively. The room temperature resistivity of Pd, Pd{sub 4}S, PdS and PdS{sub 2} were found to be respectively 0.1, 15.9, 15,000 and 20,000 μΩ cm. The temperature-dependent electrical resistivity measurements showed metallic conduction for Pd and Pd{sub 4}S films. The Seebeck coefficient measured at 300 K for these Pd–S phases showed their n-type conducting behavior. - Highlights: • Multichamber sulfurization setup designed for preparing thin films of Pd–S. • S vapor activated at 550, 600 and 700 °C results in Pd{sub 4}S, PdS and PdS{sub 2} phases. • The Seebeck coefficient of Pd–S phases shows their n-type conducting behavior. • Transport properties of Pd{sub 4}S phase show that it is a metallic phase. • High resistivity and thermopower of PdS and PdS{sub 2} show semiconducting nature.

  8. Synthesis, photophysical and preliminary investigation of the dye-sensitized solar cells properties of functionalized anthracenyl-based bipyridyl and phenanthrolyl Ru(II) complexes

    Indian Academy of Sciences (India)

    Adewale O Adeloye; Peter A Ajibade; Frances R Cummings; Lukas J Le Roux; Sampson N Mamphweli; Edson L Meyer

    2013-01-01

    Four new amphiphilic ligands: 4-(2,3-dimethylacrylic acid)-2,2'-bipyridine (L1), 4-(9-anthracenyl-10-(2,3-dimethylacrylic acid)-2,2'-bipyridine (L2), 5-(2,3-dimethylacrylic acid)-1,10-phenanthroline (L3) and 5-(9-anthracenyl-10-(2,3-dimethylacrylic acid)-1,10-phenanthroline (L4), with their corresponding homonuclear ruthenium(II) complexes formulated as cis-[Ru-(L1)3(PF6)2] (C1), cis-[Ru-(L2)3(PF6)2] (C2), cis-[Ru-(L3)3(PF6)2] (C3) and cis-[Ru-(L4)3(PF6)2] (C4), have been synthesized and characterized by elemental analysis, 1H- and 13C- NMR, FT-IR, UV-Vis and photoluminescence spectroscopy. The complexes exhibit broad and intense metal-to-ligand charge transfer (MLCT) transition bands in the visible region (400-700 nm), and red light emitting properties at room temperature. By comparison however, complexes C1 and C2 bipyridine moiety gave lower molar absorptivity coefficient at relatively similar wavelength characteristics (410-520 nm) when compared to C3 and C4 with phenanthroline based molecules. Cyclic voltammograms of the complexes revealed complex C4 with most reduction potential which might be due to increase in the conjugation of the anthracene functionalized units. Preliminary investigation of the solar cell efficiency of the complexes on TiO2 nanocrystalline films gave the best result with efficiency of 0.103% for C1 under illumination at 1000 W/m2 AM 1.5. Electrochemical impedance spectroscopy (EIS) technique however, revealed the charge transfer resistances (Rct) of the electrons on the TiO2 semiconductor.

  9. Magnetic, electronic, high-spin polarization and half-metallic properties of Ru2VGe and Ru2VSb Heusler alloys: An FP-LAPW study

    Science.gov (United States)

    Gupta, Dinesh C.; Bhat, Idris H.

    2015-01-01

    Electronic and magnetic properties of Ru2VGe and Ru2VSb have been calculated using full potential linearized augmented plane wane method. The optimized equilibrium lattice constants in stable Fm-3m configuration were found to be 6.032 Å for Ru2VGe and 6.272 Å for Ru2VSb. Spin-resolved calculations show that V mainly contributes to the magnetic properties in these materials. The materials follow the Slater-Pauling rule and hence have integral magnetic moments which is due to 100% spin polarization at Fermi energy. The calculated total magnetic moments per unit cell were found to be 1.0 μB for Ru2VGe and 2.0 μB for Ru2VSb. Both the materials having ferromagnetic ground state, exhibit half-metallicity with an energy gap in the spin-down channel of 0.095 eV for Ru2VGe and 0.186 eV for Ru2VSb.

  10. Crystal structure of the Nd(Ru{sub 0.6}Ge{sub 0.4}){sub 2} and ErRuGe compounds

    Energy Technology Data Exchange (ETDEWEB)

    Rizzoli, C.; Sologub, O.; Salamakha, P

    2003-02-17

    Using X-ray powder and single crystal diffraction, the crystal structures of the Nd(Ru{sub 0.6}Ge{sub 0.4}){sub 2} and ErRuGe compounds were investigated. The compounds belong to the KHg{sub 2} and TiNiSi type structure, respectively.

  11. Indole cyanation via C-H bond activation under catalysis of Ru(Ⅲ)-exchanged NaY zeolite (RuY) as a recyclable catalyst

    Institute of Scientific and Technical Information of China (English)

    Alireza Khorshidi

    2012-01-01

    Selective 3-cyanation of indoles was achieved under heterogeneous catalysis of Ru(Ⅲ)-exchanged NaY zeolite (RuY) as a recyclable catalyst,in combination with K4[Fe(CN)6] as a nontoxic,slow cyanide releasing agent.Under the aforementioned conditions,good yields of the desired products were obtained.

  12. Oferta ir akceptas vartojimo sutartyse

    OpenAIRE

    Ežerskytė, Ramunė

    2011-01-01

    Sutarčiai sudaryti paprastai reikia, kad viena šalis pasiūlytų sudaryti sutartį (oferta), o kita šalis sutiktų su pasiūlymu (akceptas). Sutarčių įvairovėje išskiriamos vartojimo sutartys, kurios dėl silpnesnės šalies apsaugos principo įgyvendinimo pasižymi tam tikrais ypatumais. Vartojimo sutarčių sudarymas pateikiant ofertą ir akceptą yra šio magistro baigiamojo darbo objektas. Magistro baigiamąjį darbą sudaro trys dalys. Pirmojoje darbo dalyje analizuojama vartojimo sutarties sąvoka ir spec...

  13. IRS memorandum limits joint ventures.

    Science.gov (United States)

    Herman, A W

    1992-08-01

    Based on a new memorandum, the Internal Revenue Service (IRS) will be looking at joint hospital/physician activities with greater attention to the nuances of public versus private benefit. As a result, hospitals face greater risk of losing their tax-exempt status in the maze of joint ventures, physician recruitment, and practice acquisition. To be successful, ventures will have to be backed by sound reasoning and thorough documentation.

  14. Was photosynthetic RuBisCO recruited by acquisitive evolution from RuBisCO-like proteins involved in sulfur metabolism?

    Science.gov (United States)

    Ashida, Hiroki; Danchin, Antoine; Yokota, Akiho

    2005-01-01

    Genome analyses have revealed that the genomes of non-photosynthetic bacteria including Bacillus subtilis code for proteins similar to the large subunit of RuBisCO (called RuBisCO-like protein (RLP)). This raises a fundamental question as to their functional relationship to photosynthetic RuBisCO. Recently, we identified the RLP of B. subtilis as the 2,3-diketo-5-methylthiopentyl-1-phosphate enolase in the methionine salvage pathway. In this mini-review, we suggest functional and evolutionary links between B. subtilis RLP and photosynthetic RuBisCO. Furthermore, we propose that photosynthetic RuBisCOs evolved from RLPs similar to that found in B. subtilis.

  15. Green synthesis of Pd nanoparticles at Apricot kernel shell substrate using Salvia hydrangea extract: Catalytic activity for reduction of organic dyes.

    Science.gov (United States)

    Khodadadi, Bahar; Bordbar, Maryam; Nasrollahzadeh, Mahmoud

    2017-03-15

    For the first time the extract of the plant of Salvia hydrangea was used to green synthesis of Pd nanoparticles (NPs) supported on Apricot kernel shell as an environmentally benign support. The Pd NPs/Apricot kernel shell as an effective catalyst was prepared through reduction of Pd(2+) ions using Salvia hydrangea extract as the reducing and capping agent and Pd NPs immobilization on Apricot kernel shell surface in the absence of any stabilizer or surfactant. According to FT-IR analysis, the hydroxyl groups of phenolics in Salvia hydrangea extract as bioreductant agents are directly responsible for the reduction of Pd(2+) ions and formation of Pd NPs. The as-prepared catalyst was characterized by Fourier transform infrared (FT-IR) and UV-Vis spectroscopy, field emission scanning electron microscopy (FESEM) equipped with an energy dispersive X-ray spectroscopy (EDS), Elemental mapping, X-ray diffraction analysis (XRD) and transmittance electron microscopy (TEM). The synthesized catalyst was used in the reduction of 4-nitrophenol (4-NP), Methyl Orange (MO), Methylene Blue (MB), Rhodamine B (RhB), and Congo Red (CR) at room temperature. The Pd NPs/Apricot kernel shell showed excellent catalytic activity in the reduction of these organic dyes. In addition, it was found that Pd NPs/Apricot kernel shell can be recovered and reused several times without significant loss of catalytic activity. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. A rechargeable hydrogen battery based on Ru catalysis.

    Science.gov (United States)

    Hsu, Shih-Fan; Rommel, Susanne; Eversfield, Philipp; Muller, Keven; Klemm, Elias; Thiel, Werner R; Plietker, Bernd

    2014-07-01

    Apart from energy generation, the storage and liberation of energy are among the major problems in establishing a sustainable energy supply chain. Herein we report the development of a rechargeable H2 battery which is based on the principle of the Ru-catalyzed hydrogenation of CO2 to formic acid (charging process) and the Ru-catalyzed decomposition of formic acid to CO2 and H2 (discharging process). Both processes are driven by the same catalyst at elevated temperature either under pressure (charging process) or pressure-free conditions (discharging process). Up to five charging-discharging cycles were performed without decrease of storage capacity. The resulting CO2/H2 mixture is free of CO and can be employed directly in fuel-cell technology.

  17. Metamagnetic domains in [Co/Pt]/Ru multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Kiselev, N.S. [IFW Dresden (Germany); Donetsk Inst. for Physics and Technology (Russian Federation); Bran, C.; Wolff, U.; Schultz, L.; Bogdanov, A.N.; Neu, V.; Roessler, U.K. [IFW Dresden (Germany); Hellwig, O. [Hitachi GST, San Jose (United States)

    2009-07-01

    In antiferromagnetically coupled superlattices with perpendicular anisotropy, a magnetic field induces a cascade of reorientation transitions accompanied by metamagnetic multidomain states. For a micromagnetic model, we derive equilibrium sizes of stripe and bubble metamagnetic domains as functions of the antiferromagnetic exchange, magnetic field, and geometrical parameters of the multilayers. Magnetic phase diagrams display three different types of metamagnetic domains which separate the ferrimagnetic state from the antiferromagnetic and the saturated ferromagnetic state, and from ferrostripe phases. Experimental investigations have been carried out for an antiferromagnetically coupled [(Co/Pt){sub 8}Co/Ru]{sub 18} superlattice. Magnetic force microscopy (MFM) imaging in a magnetic fields reveals peculiarities of the nucleation and evolution of metamagnetic domains. Theoretical analysis of MFM data and the magnetization curves gives a consistent description of the magnetization processes in [Co/Pt]/Ru multilayers. Demagnetization processes starting from the multidomain metamagnetic states lead to specific remanents states, namely metamagnetic band and bubble topological defects.

  18. Novel Ru - K/Carbon Nanotubes Catalyst for Ammonia Synthesis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel ammonia synthesis catalyst, potassium-promoted ruthenium supported on carbon nanotubes, was developed. It was found that the Ru-K/carbon nanotubes catalyst had higher activity for ammonia synthesis ( 20.85 ml NH 3 /h/g-cat ) than the Ru-K/fullerenes ( 13.3 ml NH 3 /h/g-cat ) at atmospheric ressure and 623 K. The catalyst had activity even at 473 K, and had the highest activity ( 23.46 ml NH 3 /h/g-cat ) at 643 K. It was suggested that the multi-walled structure favored the electron transfer, the hydrogen-storage and the hydrogen-spill which were favorable to ammonia synthesis.

  19. Stereoselective Synthesis of (Z)-α-Alkylidene-γ-Butyrolactones via Pd-Catalyzed CO Insertion and Cyclization

    Institute of Scientific and Technical Information of China (English)

    Lijun Liu; Fentair Luo

    2002-01-01

    Four new (Z)-2-phenoxymethylene-4-pentanolide derivatives and four (Z)-2-phenoxymethyl-2penten-γ-lactone derivatives were prepared via Pd-catalyzed carbon monoxide insertion and intramolecular cyclization. All compounds were characterized by IR, iH NMR, 13C NMR, MS spectra and elemental analysis. The plausible mechanism of the reaction was discussed.

  20. Olefin hydroformylation catalysis with RuCl2(DMSO4.

    Directory of Open Access Journals (Sweden)

    Marisela Reyes*

    2008-05-01

    Full Text Available The RuCl2(DMSO4 complex was used as catalytic precursor in olefin hydroformylation reactions, giving good percent yield and better selectivity for linear aldehydes. The reactions were tested in homogeneous medium and biphasic organic solvent/ water systems. The substrates tried were 1-hexene, cyclohexene, 2-methyl-2-pentene, 2,3-dimethyl-2-butene; binary mixtures and synthetic naphtha and real naphtha. The activity is better for linear olefins compared with substituted olefins.

  1. Comparing Ru and Fe-catalyzed olefin metathesis.

    Science.gov (United States)

    Poater, Albert; Chaitanya Vummaleti, Sai Vikrama; Pump, Eva; Cavallo, Luigi

    2014-08-01

    Density functional theory calculations have been used to explore the potential of Fe-based complexes with an N-heterocyclic carbene ligand, as olefin metathesis catalysts. Apart from a less endothermic reaction energy profile, a small reduction in the predicted upper energy barriers (≈ 2 kcal mol(-1)) is calculated in the Fe catalyzed profile with respect to the Ru catalysed profile. Overall, this study indicates that Fe-based catalysts have the potential to be very effective olefin metathesis catalysts.

  2. 官能化碳纳米管负载Ru催化山梨醇氢解制备低碳二元醇%Effect of modified groups of carbon nanotubes on catalytic properties of Ru/CNTs catalysts for hydrogenolysis of sorbitol

    Institute of Scientific and Technical Information of China (English)

    董慧焕; 郭星翠; 秦张峰; 韩生; 牟新东

    2015-01-01

    以不同官能化碳纳米管(原始MCN、氨基化AMCN和石墨化GMCN等)作为载体,通过浸渍法制备了Ru/CNTs催化剂,并应用于山梨醇氢解制1,2-丙二醇和乙二醇反应中. 利用XRD、HRTEM、XPS和ICP-AES等方法对催化剂进行了表征,考察了官能团性质、碱助剂等因素对山梨醇氢解性能的影响. 结果表明,与Ru/MCN或Ru/GMCN相比较,Ru/AMCN催化剂对山梨醇氢解有更高的活性,在205℃、5. 0 MPa氢压条件下,以Ca(OH)2 为添加剂,山梨醇的转化率可达99. 5%,1,2-丙二醇(1,2-PD)和乙二醇(EG)的总产率为47. 7%. 催化剂重复利用五次,催化活性无明显下降.%Ruthenium catalysts supported on carbon nanotubes with different functional groups ( MCN, AMCN and GMCN ) were prepared by incipient wetness impregnation with ultrasonic-assistance and used for the hydrogenolysis of sorbitol. The catalysts were characterized by X-ray diffraction ( XRD ) , HRTEM, X-ray photoelectron spectroscopy ( XPS) and ICP-AES. The effects of functional group species, and base additives on the catalytic performance of Ru/CNTs in the sorbitol hydrogenolysis reaction were investigated. Nearly 99. 5%of sorbitol conversion and 47 . 7% total yield of ethylene glycol and 1 , 2-propanediol ( 1 , 2-PD ) could be achieved over Ru/AMCN under mild reaction conditions (205℃, 5. 0 MPa), using Ca(OH)2 as additive. The conversion of sorbitol and the selectivity to ethylene glycol ( EG ) and 1 , 2-propanediol ( 1 , 2-PD ) did not decrease over the five repeated runs, which confirmed that the Ru/AMCN catalyst exhibited high stability in the aqueous hydrogenolysis of sorbitol to glycols.

  3. Climate Prediction Center IR 4km Dataset

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CPC IR 4km dataset was created from all available individual geostationary satellite data which have been merged to form nearly seamless global (60N-60S) IR...

  4. Calculating the melting curves by the thermodynamic data matching method: Platinum-group refractory metals (Ru, Os, and Ir)

    Science.gov (United States)

    Kulyamina, E. Yu.; Zitserman, V. Yu.; Fokin, L. R.

    2017-01-01

    A technique for reconstructing thermal properties, including the melting curve, of refractory metals based on the use of experimental data on caloric properties available up to the melting point and some regularities of the Debye-Grüneisen theory has been proposed. The calculation result is the consistent system of high-temperature thermal data, including the thermal expansion coefficient, solid-phase density, and volume jump upon melting. This technique was tried-out on refractory platinum-group metals based on experimental data on the enthalpy of the metals and confirmed by consistency with a thermodynamic calculation using shock-wave experiments and results obtained by the quantum molecular dynamics method.

  5. Core-level photoemission from alkali metals on Ru(001)

    Energy Technology Data Exchange (ETDEWEB)

    Shek, M. (Department of Physics, Hunter College of The City University of New York, New York, New York 10021 (USA)); Hrbek, J. (Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000 (USA)); Sham, T.K. (Department of Chemistry, University of Western Ontario, London, Ontario, Canada NA65B7 (Canada)); Xu, G. (Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000 (USA))

    1990-02-15

    We report soft-x-ray photoemission results on the core-level binding energies of Li, Na, K, and Cs adsorbed on Ru(001). For all four alkali metals, the saturated alkali-metal--Ru interface core level and the second- (surface-) layer core-level binding energies differ by as much as 0.85--1.25 eV. Surface versus bulklike core-level shifts are reported for Li, K, and Cs, which are 0.55 eV for Li and {similar to}0.25 eV for the other two. For increasing coverages of Li, Na, and K in direct contact with Ru, there are significant decreases in the core-level binding energies, the total shift ranging from {similar to}{minus}1.25 eV for Li to {similar to}{minus}0.80 eV for K; the shift for Cs is small and the reasons for the deviation are discussed. A comparison between our observations and the prediction from the thermodynamic model of Johannson and Martensson is also given.

  6. Aluminum thin film growth on a Ru(0001) surface

    Science.gov (United States)

    Ceballos, G.; Theis, M.; Pelzer, Th.; Schick, M.; Rangelov, G.; Wandelt, K.

    1995-07-01

    The growth of thin Al films on a Ru(0001) substrate has been investigated by means of AES, LEED, TDS, and PAX measurements. A plot of the Ru and Al AES intensities versus evaporation time for a deposition temperature of 300 K reveals a distinct break at θAl = 1, while for higher coverages the Ru intensity decays exponentially indicating a three-dimensional growth of Al clusters. From this behavior we deduce a Stranski-Krastanov growth mechanism. This behavior persists up to 650 K. For higher deposition temperatures a diffusion of Al into the substrate and a partial desorption of the Al film is found. At low Al coverage the LEED pattern reveals an initial film growth with Al(111) structure and an expansion of the interatomic spacing of 2% compared to the Al(111) bulk plane. This superstructure persisted up to ˜ 2.5 ML. In the submonolayer regime CO and Xe TD-spectra as well as Xe 4d PAX-spectra suggest together with LEED an island growth.

  7. Optical spectroscopy of RU Cam, a pulsating carbon star

    CERN Document Server

    Kipper, Tonu

    2007-01-01

    We analysed the high resolution spectra of a RU Cam, classified as W Vir type star. The atmospheric parameters of RU Cam were estimated Teff=5250K and log g=1.0. The hydrogen deficiency of RU Cam was not confirmed. The iron abundance, [Fe/H]=-0.37, is close to the solar one. Abundances of most other elements are also close to normal. We found considerable excesses of carbon and nitrogen: [C/Fe]=+0.98, [N/Fe]=+0.60. The carbon to oxygen ratio is C/O$\\ge$1. The carbon isotopic abundance ratio is equal to C^12/C^13=4.5. For sodium a moderate overabundance Na/Fe=+0.55 was obtained. For two moments of observations we found close heliocentric velocity values, Vr=-21.7+/-0.8 and -23.1+/-1.0 km/s. Both spectra contain a peculiar feature - an emission component of NaI doublet which location agrees with the radial velocity from the bulk of metallic lines. For our two observing moments we found no dependence of radial velocities on the formation depth or on excitation energy for metallic lines.

  8. Reactivity of periodically rippled graphene grown on Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Borca, B; Calleja, F; Hinarejos, J J; Vazquez de Parga, A L; Miranda, R [Departamento de Fisica de la Materia Condensada, Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid (Spain)

    2009-04-01

    We report here the reactivity of epitaxial graphene islands and complete monolayers on Ru(0001) towards molecular oxygen and air. The graphene is prepared by thermal decomposition of ethylene molecules pre-adsorbed on an Ru(0001) surface in an ultra-high vacuum chamber. The graphene layer presents a periodically rippled structure that is dictated by the misfit between graphene and Ru(0001) lattice parameters. The periodic ripples produce spatial charge redistribution in the graphene and modifies its electronic structure around the Fermi level. In order to investigate the reactivity of graphene we expose graphene islands to a partial pressure of oxygen and following the evolution of the surface by STM during the exposure. For the exposure to air we removed the sample from the UHV chamber and we re-introduce it after several hours, taking STM images before and after. The surface areas not covered by the graphene islands present a dramatic change but the graphene structure, even the borders of the islands, remain intact. In the case of a complete graphene monolayer the exposure to oxygen or to air does not affect or destroy the rippled structure of the graphene monolayer.

  9. Ruthenocuprates RuSr2(Eu,Ce)2Cu2O10-y: Intrinsic magnetic multilayers

    Science.gov (United States)

    Živković, I.; Hirai, Y.; Frazer, B. H.; Prester, M.; Drobac, D.; Ariosa, D.; Berger, H.; Pavuna, D.; Margaritondo, G.; Felner, I.; Onellion, M.

    2002-04-01

    We report ac susceptibility data on RuSr2(Eu,Ce)2Cu2O10-y (Ru-1222, Ce content x=0.5 and 1.0), RuSr2GdCu2O8 (Ru-1212), and SrRuO3. Both Ru-1222 (x=0.5, 1.0) sample types exhibit unexpected magnetic dynamics in low magnetic fields: logarithmic time relaxation, switching behavior, and ``inverted'' hysteresis loops. Neither Ru-1212 nor SrRuO3 exhibit such magnetic dynamics. The results are interpreted as evidence of the complex magnetic order in Ru-1222. We propose a specific multilayer model to explain the data, and note that superconductivity in the ruthenocuprate is compatible with both the presence and absence of the magnetic dynamics.

  10. Orientation-Dependent Oxygen Evolution on RuO2 without Lattice Exchange

    DEFF Research Database (Denmark)

    Stoerzinger, Kelsey A.; Diaz-Morales, Oscar; Kolb, Manuel

    2017-01-01

    RuO2 catalysts exhibit record activities toward the oxygen evolution reaction (OER), which is crucial to enable efficient and sustainable energy storage. Here we examine the RuO2 OER kinetics on rutile (110), (100), (101), and (111) orientations, finding (100) the most active. We assess the poten......RuO2 catalysts exhibit record activities toward the oxygen evolution reaction (OER), which is crucial to enable efficient and sustainable energy storage. Here we examine the RuO2 OER kinetics on rutile (110), (100), (101), and (111) orientations, finding (100) the most active. We assess...... work, suggesting lattice oxygen is not exchanged in catalyzing OER on crystalline RuO2 surfaces. This hypothesis is supported by the correlation of activity with the number of active Ru-sites calculated by density functional theory, where more active facets bind oxygen more weakly. This new...

  11. Pt-Ru Catalysts Prepared by a Modified Polyol Process for Direct Methanol Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Junmin; ZHU Fangfang; ZHANG Kunhua; LIU Weiping; GUAN Weiming

    2012-01-01

    Supported PtRu/C catalysts used in direct methanol fuel cells (DMFCs) were prepared by a new modified polyol method.Transmission electron microscopy (TEM),X-ray diffraction (XRD) and cyclic voltammograms (CVs) were carried out to characterize the morphology,composition and the electrochemical properties of the PtRu/C catalyst.The results revealed that the PtRu nanoparticles with small average particle size (≈2.5 nm),and highly dispersed on the carbon support.The PtRu/C catalyst exhibited high catalytic activity and anti-poisoned performance than that of the JM PtRu/C.It is imply that the modified polyol method is efficient for PtRu/C catalyst preparation.

  12. Kinetic study of methanol oxidation on Pt2Ru3/C catalyst in the alkaline media

    Directory of Open Access Journals (Sweden)

    A. V. TRIPKOVIC

    2007-11-01

    Full Text Available The interaction of acridine orange (AO with double-stranded (ds The electrochemical oxidation of methanol in NaOH solution was examined on a thin film Pt2Ru3/C electrode. The XRD pattern revealed that the Pt2Ru3 alloy consisted of a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru. It was shown that in alkaline solution, the difference in activity between Pt/C and Pt2Ru3/C is significantly smaller than in acid solution. It is proposed that the reaction follows a quasi bifunctional mechanism. The kinetic parameters indicated that the chemical reaction between adsorbed COad and OHad species could be the rate limiting step.

  13. Effects of Promoters on a Ru/Sepiolite Catalyst for Carbon Dioxide Methanation

    Institute of Scientific and Technical Information of China (English)

    Laitao Luo; Songjun Li; Yan Ouyang

    2003-01-01

    In this work, CO2 methanation has been investigated over Ru-based catalysts. The effects of promoters on the activity, selectivity and reduction properties of the Ru/sepiolite catalyst were analyzed by kinetic and thermodynamic methods. The catalysts were characterized by means of TPD, and the results revealed that the addition of Mo, Mn or Co improved the properties of the Ru/sepiolite catalyst.The effects of promoters could affect the change of enthalpy, entropy and chemical potential.

  14. Stability, structural, elastic and electronic properties of RuN polymorphs from first-principles calculations

    Science.gov (United States)

    Bannikov, V. V.; Shein, I. R.; Ivanovskii, A. L.

    2010-05-01

    First-principles FLAPW-GGA calculations for six possible polymorphs of ruthenium mononitride RuN indicate that the most stable structure is that of zinc blende rather than the rock salt structure recently reported for synthesized RuN samples. The elastic, electronic properties and the features of chemical bonds of zinc-blende RuN polymorph were investigated and discussed in detail.

  15. Phototoxicity of strained Ru(ii) complexes: is it the metal complex or the dissociating ligand?

    Science.gov (United States)

    Azar, Daniel F; Audi, Hassib; Farhat, Stephanie; El-Sibai, Mirvat; Abi-Habib, Ralph J; Khnayzer, Rony S

    2017-07-27

    A photochemically dissociating ligand in Ru(bpy)2(dmphen)Cl2 [bpy = 2,2'-bipyridine; dmphen = 2,9-dimethyl-1,10-phenanthroline] was found to be more cytotoxic on the ML-2 Acute Myeloid Leukemia cell line than Ru(bpy)2(H2O)2(2+) and prototypical cisplatin. Our findings illustrate the potential potency of diimine ligands in photoactivatable Ru(ii) complexes.

  16. A Novel Ultrafine Ru-B Amorphous Alloy Catalyst for Glucose Hydrogenation to Sorbitol

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An ultrafine Ru-B amorphous alloy catalyst was prepared by chemical reduction with KBH4 in aqueous solution, which exhibited perfect selectivity to sorbitol (~100%) and very high activity during the liquid phase glucose hydrogenation, much higher than the corresponding crystallized Ru-B, the pure Ru powder, and Raney Ni catalysts. The correlation of the catalytic activity to both the structural and surface electronic characteristics was discussed briefly.

  17. Spontaneous deposition of Ru on Pt (100: morphological and electrochemical studies. Preliminary results of ethanol oxidation at Pt(100/Ru

    Directory of Open Access Journals (Sweden)

    Colle Vinicius D.

    2003-01-01

    Full Text Available In the present work ruthenium was deposited in submonolayer amounts on Pt(100 by spontaneous deposition at several deposition times. The Pt (100/Ru surfaces were analyzed using ex-situ STM to image the deposits characteristic of ruthenium on Pt (100. It was observed the formation of ruthenium islands with diameters between 1.0 and 4.5 nm with bi-atomic thickness in the center of the islands. A homogeneous distribution of the ruthenium islands on the platinum terraces was found, with no preferential deposition on steps or surface defect sites. The ruthenium coverage degree had been calculated by the decrease of charge of the hydrogen adsorption-desorption peaks in the cyclic voltammograms of the Pt(100/Ru electrodes. The Pt(100/Ru electrodes with a ruthenium coverage degree of ca. 0.3 showed a high activity for the ethanol electrooxidation. The electrochemical experimental results support strongly the bifunctional mechanism for the enhanced ethanol oxidation.

  18. Anomalous magnetic fluctuations in superconducting Sr2RuO4 revealed by 101Ru nuclear spin-spin relaxation

    Science.gov (United States)

    Manago, Masahiro; Yamanaka, Takayoshi; Ishida, Kenji; Mao, Zhiqiang; Maeno, Yoshiteru

    2016-10-01

    We carried out 101Ru nuclear quadrupole resonance (NQR) measurement on superconducting (SC) Sr2RuO4 under zero magnetic field (H =0 ) and found that the nuclear spin-spin relaxation rate 1 /T2 is enhanced in the SC state. The 1 /T2 measurement in the SC state under H =0 is effective for detecting slow magnetic fluctuations parallel to the quantized axis of the nuclear spin. Our results indicate that low-energy magnetic fluctuations perpendicular to the RuO2 plane emerge when the superconductivity sets in, which is consistent with the previous 17O-NQR result that the nuclear spin-lattice relaxation rate 1 /T1 of the in-plane O site exhibits anomalous behavior in the SC state. The enhancement of the magnetic fluctuations in the SC state is unusual and suggests that the fluctuations are related to the unconventional SC pairing. We suggest that this phenomenon is a consequence of the spin degrees of freedom of the spin-triplet pairing.

  19. Pd segregation to the surface of Au on Pd(111) and on Pd/TiO2(110)

    Science.gov (United States)

    Sharpe, Ryan; Counsell, Jon; Bowker, Michael

    2017-02-01

    The interaction of Au and Pd in bimetallic systems is important in a number of areas of technology, especially catalysis. In order to investigate the segregation behaviour in such systems, the interaction of Pd and Au was investigated by surface science methods. In two separate sets of experiments, Au was deposited onto a Pd(111) single crystal, and Pd and Au were sequentially deposited onto TiO2(110), all in ultra-high vacuum using metal vapour deposition. Heating Au on Pd/TiO2(110) to 773 K resulted in the loss of the Au signal in the LEIS, whilst still remaining present in the XPS, due to segregation of Pd to the surface and the formation of a Au-Pd core-shell structure. It is likely that this is due to alloying of Au with the Pd and surface dominance of that alloy by Pd. The Au:Pd XPS peak area ratio is found to substantially decrease on annealing Au/Pd(111) above 773 K, corresponding with a large increase in the CO sticking probability to that for clean Pd(111). This further indicates that Au diffuses into the bulk of Pd on annealing to temperatures above 773 K. It therefore appears that Au prefers to be in the bulk in these systems, reflecting the exothermicity of alloy formation.

  20. Triaxial shapes in the ground states of even-even neutron-rich Ru isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Lister, C.J.; Morss, L.R. [and others

    1995-08-01

    Partial level schemes for {sup 108,110,112}Ru, and {sup 114}Ru about which nothing was previously known, were determined from the measurement of prompt, triple-gamma coincidences in {sup 248}Cm fission fragments. A 5-mg {sup 249}Cm source, mixed with 65-mg KCl and pressed in the form of a 7-mm diameter pellet, was used for the experiment. Prompt {gamma} rays emitted from the fission fragments were detected with the Eurogam array at Daresbury, which at that time consisted of 45 Compton suppressed Ge detectors and 5 LEPS spectrometers. Transitions in Ru were identified by gating on {gamma} rays in the complementary Te fragments. Figure I-25 shows the technique used to identify the previously unknown transitions in {sup 114}Ru and its partial level scheme. High spin states up to spin 10 h were observed and the {gamma}-ray branching ratios were determined. The ratios of electric quadrupole transition probabilities deduced from the experimental branching ratios were found to be in good agreement with the predictions of a simple model of rigid triaxial rotor. Our analysis shows that gamma deformation in Ru isotopes is increasing with the neutron number and the gamma value for {sup 112}Ru and {sup 114}Ru is {approximately} 25 degrees. This is one of the highest gamma values encountered in nuclei, suggesting soft triaxial shapes for {sup 112}Ru and {sup 114}Ru. The results of this investigation were published.

  1. Thermal stability of RuO sub 2 -based bottom electrodes during various ambient annealings

    CERN Document Server

    Ahn, J H; Choi, G P; Choi, W Y; Kim, H G; Lee, W J; Yoon, S G

    1999-01-01

    RuO sub 2 thin films were prepared on SiO sub 2 /Si, TiN/SiO sub 2 /Si and Ru/poly-Si by using DC magnetron sputtering. The annealing of the RuO sub 2 -based bottom electrodes was performed in oxygen and argon ambients and in high vacuum in the temperature range of 400 .deg. C approx 800 .deg. C. In oxygen-ambient annealing, the surface morphology was drastically changed due to the evaporation of ruthenium dioxides in the form of RuO sub 3 and RuO sub 4. The RuO sub 2 thin film annealed in high vacuum was reduced to the Ru metal phase. Evaporation and reduction of the RuO sub 2 thin films could actually be observed during the deposition of (Ba,Sr)TiO sub 3 thin films. oxygen diffusion through the RuO sub 2 /diffusion barrier/poly-Si structures is also discussed

  2. Magnetic properties and spin polarization of Ru doped half metallic CrO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    West, Kevin G.; Dao, Nam N. H.; Lu, Jiwei, E-mail: jl5tk@virginia.edu [Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Osofsky, Michael; Mazin, I. I. [Naval Research Laboratory, Washington, DC 20375 (United States); Wolf, Stuart A. [Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Department of Physics, University of Virginia, Charlottesville, Virginia 22904 (United States)

    2015-07-06

    Chromium dioxide (CrO{sub 2}) is a half metal that is of interest for spintronic devices. It has not been synthesized through traditional physical vapor deposition (PVD) techniques because of its thermodynamic instability in low oxygen pressures. Epitaxial thin films of Ru doped tetragonal rutile CrO{sub 2} were synthesized by a PVD technique. The as-deposited Ru{sub x}Cr{sub 1−x}O{sub 2} was ferrimagnetic with the saturation magnetization moment showing a strong dependence on the Ru concentration. Curie temperature as high as 241 K has been obtained for ∼23 at. % Ru. The Ru substitution increased the electrical conductivity by increasing the minority spin concentration. The spin polarization was found to be as high as 70% for 9 at. % Ru and decreased to ∼60% with Ru concentrations up to ∼44 at. %, which is determined by the Fermi velocities of the majority and minority spins. First principle calculations were performed to understand the effect of Ru content on the properties of CrO{sub 2}. The PVD processes of Ru doped CrO{sub 2} could lead to the practical applications of the high spin polarization of CrO{sub 2} in spintronic devices.

  3. Phase diagrams of Ca(Fe,Ru){sub 2}As{sub 2} system

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Kan; Gegenwart, Philipp [Experimentalphysik VI, Elektronische Korrelationen und Magnetismus, Institut fuer Physik, Universitaet Augsburg, D-86135 Augsburg (Germany)

    2015-07-01

    Single crystalline Ca(Fe,Ru){sub 2}As{sub 2} series have been grown and characterized by structural, magnetic, and transport measurements. These measurement shows Ca(Fe,Ru){sub 2}As{sub 2} undergoes successive phase transitions with increasing Ru element doping. The antiferromagnetic phase with orthorhombic structure at x<0.023 (x means the doping concentration of Ru element) is directly driven to a Fermi-liquid type collapsed tetragonal (cT) phase at 0.023

  4. Characterization of a trinuclear ruthenium species in catalytic water oxidation by Ru(bda)(pic)2 in neutral media.

    Science.gov (United States)

    Zhang, Biaobiao; Li, Fei; Zhang, Rong; Ma, Chengbing; Chen, Lin; Sun, Licheng

    2016-06-30

    A Ru(III)-O-Ru(IV)-O-Ru(III) type trinuclear species was crystallographically characterized in water oxidation by Ru(bda)(pic)2 (H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; pic = 4-picoline) under neutral conditions. The formation of a ruthenium trimer due to the reaction of Ru(IV)[double bond, length as m-dash]O with Ru(II)-OH2 was fully confirmed by chemical, electrochemical and photochemical methods. Since the oxidation of the trimer was proposed to lead to catalyst decomposition, the photocatalytic water oxidation activity was rationally improved by the suppression of the formation of the trimer.

  5. Moisture map by IR thermography

    Science.gov (United States)

    Grinzato, E.; Cadelano, G.; Bison, P.

    2010-10-01

    A new approach to moisture detection in buildings by an optical method is presented. Limits of classical and new methods are discussed. The state of the art about the use of IR thermography is illustrated as well. The new technique exploits characteristics of the materials and takes into account explicitly the heat and mass exchange between surface and environment. A set of experiments in controlled laboratory conditions on different materials is used to better understand the physical problem. The testing procedure and the data reduction are illustrated. A case study on a heritage building points up the features of this technique.

  6. A New Heteroleptic Biquinoline Ruthenium(II Sensitizer for Near-IR Sensitization of Nanocrystalline TiO2

    Directory of Open Access Journals (Sweden)

    Surya Prakash Singh

    2013-01-01

    Full Text Available Ruthenium(II complex containing cis-[Ru(H2dcbiq(L(NCS2], where H2dcbiq = 4,4′-dicarboxy-2,2′-biquinoline and L = 4,4′-di-tert-butyl-2-2′-dipyridyl coded as SPS-02, was synthesized and fully characterized. This complex showed appreciably broad absorption range. The new complex was used as photosensitizer in nanocrystalline TiO2 dye-sensitized solar cell application. cis-[Ru(H2dcbiq(L(NCS2] (SPS-02 achieved efficient sensitization of nanocrystalline TiO2 over the whole visible range, extending into the near-IR region (ca. 1000 nm with superior short-circuit photocurrent density ( = 9.13 mA cm−2 and conversion efficiency (η = 2.09% compared with complex cis-[Ru(H2dcbiq2(NCS2] (1 under an irradiation of full sunlight (100 mW cm−2.

  7. Transport properties of Heusler compounds Ru{sub 2}CrGe and Ru{sub 2}CrSn under high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Okada, H; Koyama, K; Watanabe, K [High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai (Japan); Kusakari, Y; Kanomata, T [Faculty of Engineering, Tohoku Gakuin University, Tagajo (Japan); Matsuoka, E; Onodera, H, E-mail: hironari@imr.tohoku.ac.j [Department of Physics, Graduate School of Science, Sendai (Japan)

    2009-03-01

    We have performed the specific heat and the electrical resistivity measurements under high magnetic fields for Heusler compounds Ru{sub 2}CrGe and Ru{sub 2}CrSn. We found that the electrical resistivity for Ru{sub 2}CrGe shows an upturn in the vicinity of 130 K and changes a metallic to a semiconducting-like behavior with decreasing temperature. By applying magnetic field, a negative magnetoresistance was observed below 200 K. On the other hand, the electrical resistivity for Ru{sub 2}CrSn shows a semimetallic-like behavior. The results of the electrical resistivity in Ru{sub 2}CrGe suggest that the compound has a gap-like structure in the electronic structure at the Fermi level. Moreover, it was found that another phase transition occurs in Ru{sub 2}CrGe and Ru{sub 2}CrSn, in addition to the magnetic transition.

  8. Targeting human telomeric G-quadruplex DNA and inhibition of telomerase activity with [(dmb2Ru(obipRu(dmb2](4+.

    Directory of Open Access Journals (Sweden)

    Shuo Shi

    Full Text Available Inhibition of telomerase by inducing/stabilizing G-quadruplex formation is a promising strategy to design new anticancer drugs. We synthesized and characterized a new dinuclear complex [(dmb2Ru(obipRu(dmb2](4+ (dmb = 4,4'-dimethyl-2,2'-bipyridine, obip = (2-(2-pyridylimidazo[4,5-f][1,10]phenanthroline with high affinity for both antiparallel and mixed parallel / antiparallel G-quadruplex DNA. This complex can promote the formation and stabilize G-quadruplex DNA. Dialysis and TRAP experiments indicated that [(dmb2Ru(obipRu(dmb2](4+ acted as an excellent telomerase inhibitor due to its obvious selectivity for G-quadruplex DNA rather than double stranded DNA. In vitro co-culture experiments implied that [(dmb2Ru(obipRu(dmb2](4+ inhibited telomerase activity and hindered cancer cell proliferation without side effects to normal fibroblast cells. TUNEL assay indicated that inhibition of telomerase activity induced DNA cleavage further apoptosis in cancer cells. Therefore, Ru(II complex represents an exciting opportunity for anticancer drug design by specifically targeting cancer cell G-quadruplexes DNA.

  9. Supergene neoformation of Pt-Ir-Fe-Ni alloys: multistage grains explain nugget formation in Ni-laterites

    Science.gov (United States)

    Aiglsperger, Thomas; Proenza, Joaquín A.; Font-Bardia, Mercè; Baurier-Aymat, Sandra; Galí, Salvador; Lewis, John F.; Longo, Francisco

    2016-11-01

    Ni-laterites from the Dominican Republic host rare but extremely platinum-group element (PGE)-rich chromitites (up to 17.5 ppm) without economic significance. These chromitites occur either included in saprolite (beneath the Mg discontinuity) or as `floating chromitites' within limonite (above the Mg discontinuity). Both chromitite types have similar iridium-group PGE (IPGE)-enriched chondrite normalized patterns; however, chromitites included in limonite show a pronounced positive Pt anomaly. Investigation of heavy mineral concentrates, obtained via hydroseparation techniques, led to the discovery of multistage PGE grains: (i) Os-Ru-Fe-(Ir) grains of porous appearance are overgrown by (ii) Ni-Fe-Ir and Ir-Fe-Ni-(Pt) phases which are overgrown by (iii) Pt-Ir-Fe-Ni mineral phases. Whereas Ir-dominated overgrowths prevail in chromitites from the saprolite, Pt-dominated overgrowths are observed within floating chromitites. The following formation model for multistage PGE grains is discussed: (i) hypogene platinum-group minerals (PGM) (e.g. laurite) are transformed to secondary PGM by desulphurization during serpentinization; (ii) at the stages of serpentinization and/or at the early stages of lateritization, Ir is mobilized and recrystallizes on porous surfaces of secondary PGM (serving as a natural catalyst) and (iii) at the late stages of lateritization, biogenic mediated neoformation (and accumulation) of Pt-Ir-Fe-Ni nanoparticles occurs. The evidence presented in this work demonstrates that in situ growth of Pt-Ir-Fe-Ni alloy nuggets of isometric symmetry is possible within Ni-laterites from the Dominican Republic.

  10. [RuII(NO+)]3+-core complexes with 4-methyl-pyrimidine and ethyl-isonicotinate: synthesis, X-ray structure, spectroscopy, and computational and NO-release studies upon UVA irradiation.

    Science.gov (United States)

    Tamasi, Gabriella; Curci, Matia; Berrettini, Francesco; Justice, Nicholas; Sega, Alessandro; Chiasserini, Luisa; Cini, Renzo

    2008-10-01

    The reaction of RuCl(3)(NO).H(2)O with 4-methylpyrimidine (MePYM) and ethylisonicotinate (EINT), in absolute ethanol at 40-55 degrees C afforded crystalline trans-[RuCl(3)(NO)L(2)] complexes. Structural studies via X-ray diffraction, and spectroscopic methods (NMR, IR, UV-visible (UV-Vis)) revealed that the molecular structures have the two Ls in trans positions (axial) and the chloride anions and the NO(+) cation as equatorial ligands; pyrimidine...pyrimidine pairing pattern via two weak C-H...N interactions occur. The molecular structures for the EINT derivative was inferred from spectroscopy and computations. Under irradiation at 366 nm several solutions of the title compounds deliver NO via first order processes. Visible light (420-700 nm) does not produce significant NO release from CH(2)Cl(2) and CH(3)CN solutions within 24h.

  11. Synthesis and structural characterization of Pd(II) complexes derived from perimidine ligand and their in vitro antimicrobial studies

    Science.gov (United States)

    Azam, Mohammad; Warad, Ismail; Al-Resayes, Saud I.; Alzaqri, Nabil; Khan, Mohammad Rizwan; Pallepogu, Raghavaiah; Dwivedi, Sourabh; Musarrat, Javed; Shakir, Mohammad

    2013-09-01

    A novel series of Pd(II) complexes derived from 2-thiophenecarboxaldehyde and 1,8-diaminonaphthalene has been synthesized and characterized by various physico-chemical and spectroscopic techniques viz., elemental analyses, IR, UV-vis, 1H and 13C NMR spectroscopy, and ESI-mass spectrometry. The structure of ligand, 2-(2-thienyl)-2,3-dihydro-1H-perimidine has been ascertained on the basis of single crystal X-ray diffraction. All Pd(II) complexes together with the corresponding ligand have been evaluated for their ability to suppress the in vitro growth of microbes, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Citrobacter sp., Bacillus subtilis and Stenotrophomonas acidaminiphila and results show that Pd(II) complexes have more significant antimicrobial activity than their corresponding ligand. Fluorescence spectroscopic measurements clearly support that both of the Pd(II) complexes show significant DNA binding with calf thymus DNA.

  12. Coprates Chasma Landslides in IR

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Today's daytime IR image is of a portion of Coprates Chasma, part of Valles Marineris. As with yesterday's image, this image shows multiple large landslides. Image information: IR instrument. Latitude -8.2, Longitude 300.2 East (59.8 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  13. Catalytic combustion of methane over Pd/MWCNTs under lean fuel conditions%Pd/MWCNTs贫燃甲烷催化燃烧性能研究

    Institute of Scientific and Technical Information of China (English)

    高秀慧; 王胜; 高典楠; 刘为钢; 陈志萍; 汪明哲; 王树东

    2016-01-01

    The raw multi-walled carbon nanotubes ( MWCNTs) were treated with nitric acid. The shift of the surface functional groups on the MWCNTs was observed with XPS. The Pd/MWCNTs catalysts were synthesized by the ultrasonic impregnation method. The total contents of oxygen, hydroxyl and carbonyl groups were measured. The dispersion and size distribution of Pd particles were characterized with TEM. The dependence of Pd dispersion on the oxygen-containing functional groups was validated. The effect of pretreatment on the catalytic activity and stability for methane combustion was investigated under lean fuel conditions. It is shown that the catalytic activity depends on the valence state and particle size of palladium. The transformation from Pd to PdO possibly caused the decrease in the catalytic activity. Another factor inducing deactivation is Pd particle aggregation. The reaction mechanism for methane combustion over the Pd/MWCNTs catalyst is postulated on the basis of the intermediate species detected by in-situ FT-IR spectroscopy.%以MWCNTs为载体,用HNO3做氧化剂对MWCNTs进行处理,通过XPS研究了处理前后MWCNTs表面官能团的变化,并采用超声浸渍法制得Pd/MWCNTs催化剂,借助TEM,揭示了Pd粒子在催化剂表面分散度和粒径与MWCNTs表面含氧量、羟基和羰基间的关系。并考察了Pd/MWCNTs催化剂预处理方法对低浓甲烷催化燃烧活性和稳定性的影响,研究表明,Pd的价态以及Pd粒子的粒径,都与催化剂的甲烷燃烧活性直接关联。单质Pd的氧化和Pd粒径的长大是导致催化剂性能衰减的原因。通过原位FT-IR技术对反应气氛下中间物种的监测,提出了Pd/MWCNTs催化剂上的低浓度甲烷催化氧化反应机理。

  14. Ternary Pt-Ru-Ni catalytic layers for methanol electrooxidation prepared by electrodeposition and galvanic replacement

    Directory of Open Access Journals (Sweden)

    Athanasios ePapaderakis

    2014-06-01

    Full Text Available Ternary Pt-Ru-Ni deposits on glassy carbon substrates, Pt-Ru(Ni/GC, have been formed by initial electrodeposition of Ni layers onto glassy carbon electrodes, followed by their partial exchange for Pt and Ru, upon their immersion into equimolar solutions containing complex ions of the precious metals. The overall morphology and composition of the deposits has been studied by SEM microscopy and EDS spectroscopy. Continuous but nodular films have been confirmed, with a Pt÷Ru÷Ni % bulk atomic composition ratio of 37÷12÷51 (and for binary Pt-Ni control systems of 47÷53. Fine topographical details as well as film thickness have been directly recorded using AFM microscopy. The composition of the outer layers as well as the interactions of the three metals present have been studied by XPS spectroscopy and a Pt÷Ru÷Ni % surface atomic composition ratio of 61÷12÷27 (and for binary Pt-Ni control systems of 85÷15 has been found, indicating the enrichment of the outer layers in Pt; a shift of the Pt binding energy peaks to higher values was only observed in the presence of Ru and points to an electronic effect of Ru on Pt. The surface electrochemistry of the thus prepared Pt-Ru(Ni/GC and Pt(Ni/GC electrodes in deaerated acid solutions (studied by cyclic voltammetry proves the existence of a shell consisting exclusively of Pt-Ru or Pt. The activity of the Pt-Ru(Ni deposits towards methanol oxidation (studied by slow potential sweep voltammetry is higher from that of the Pt(Ni deposit and of pure Pt; this enhancement is attributed both to the well-known Ru synergistic effect due to the presence of its oxides but also (based on the XPS findings to a modification effect of Pt electronic properties.

  15. Synthesis and unexpected reactivity of [Ru(6 -cymene)Cl2 (PPh2 Cl)], leading to [Ru(6 -cymene)Cl2 (PPh2H)] and [Ru(6-cymene)Cl2 (PPh2OH)] complexes

    Indian Academy of Sciences (India)

    Arun Kumar Pandiakumar; Ashoka G Samuelson

    2015-08-01

    The reaction of [Ru(6-cymene)Cl2]2 and PPh2Cl in the ratio 1:2 gives a stable [Ru(6-cymene) Cl2(PPh2Cl)] complex. Attempts to make the cationic [Ru(6-cymene)Cl(PPh2Cl)2]Cl with excess PPh2Cl and higher temperatures led to adventitious hydrolysis and formation of [Ru(6-cymene)Cl2 (PPh2OH)]. Attempts to make a phosphinite complex by reacting [Ru(6-cymene)Cl2]2 with PPh2Cl in the presence of an alcohol results in the reduction of PPh2Cl to give [Ru(6-cymene)Cl2(PPh2H)] and the expected phosphinite. The yield of the hydride complex is highest when the alcohol is 1-phenyl-ethane-1,2-diol. All three half-sandwich complexes are characterized by X-ray crystallography. Surprisingly, the conversion of chlorodiphenylphosphine to diphenylphosphine is mediated by 1-phenyl-ethane-1,2-diol even in the absence of the ruthenium half-sandwich precursor.

  16. Prediction of strong O-H/M hydrogen bonding between water and square-planar Ir and Rh complexes.

    Science.gov (United States)

    Janjić, G V; Milosavljević, M D; Veljković, D Ž; Zarić, S D

    2017-03-20

    Intermolecular O-H/M interactions, between a water molecule and square-planar acac complexes ([M(acac)L2]), with different types of L ligands (en, H2O, CO, CN(-), and OH(-)) and different types of metal atoms (Ir(i), Rh(i), Pt(ii), and Pd(ii)) were studied by high level ab initio calculations. Among the studied neutral complexes, the [Pd(acac)(CN)(CO)] complex forms the weakest interaction, -0.62 kcal mol(-1), while the [Ir(acac)(en)] complex forms the strongest interaction, -9.83 kcal mol(-1), which is remarkably stronger than the conventional hydrogen bond between two water molecules (-4.84 kcal mol(-1)).

  17. Synthesis and Evaluation of In Vitro DNA/Protein Binding Affinity, Antimicrobial, Antioxidant and Antitumor Activity of Mononuclear Ru(II) Mixed Polypyridyl Complexes.

    Science.gov (United States)

    Putta, Venkat Reddy; Chintakuntla, Nagamani; Mallepally, Rajender Reddy; Avudoddi, Srishailam; K, Nagasuryaprasad; Nancherla, Deepika; V V N, Yaswanth; R S, Prakasham; Surya, Satyanarayana Singh; Sirasani, Satyanarayana

    2016-01-01

    The four novel Ru(II) complexes [Ru(phen)2MAFIP](2+) (1) [MAFIP = 2-(5-(methylacetate)furan-2-yl)-1 H-imidazo[4,5-f] [1, 10]phenanthroline, phen = 1,10-Phenanthroline], [Ru(bpy)2MAFIP](2+) (2) (bpy = 2,2'-bipyridine) and [Ru(dmb)2MAFIP](2+) (3) (dmb = 4,4'-dimethyl-2,2'-bipyridine) and [Ru(hdpa)2MAFIP](2+) (4) (hdpa = 2,2-dipyridylamine) have been synthesized and fully characterized via elemental analysis, NMR spectroscopy, EI-MS and FT-IR spectroscopy. In addition, the DNA-binding behaviors of the complexes 1-4 with calf thymus DNA were investigated by UV-Vis absorption, fluorescence studies and viscosity measurement. The DNA-binding experiments showed that the complexes 1-4 interact with CT-DNA through an intercalative mode. BSA protein binding affinity of synthesized complexes was determined by UV/Vis absorption and fluorescence emission titrations. The binding affinity of ruthenium complexes was supported by molecular docking. The photoactivated cleavage of plasmid pBR322 DNA by ruthenium complexes 1-4 was investigated. All the synthesized compounds were tested for antimicrobial activity by using three Gram-negative (Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) and three Gram-positive (Micrococcus luteus, Bacillus subtilis and Bacillus megaterium) organisms, these results indicated that complex 3 was more activity compared to other complexes against all tested microbial strains while moderate antimicrobial activity profile was noticed for complex 4. The antioxidant activity experiments show that the complexes exhibit moderate antioxidant activity. The cytotoxicity of synthesized complexes on HeLa cell lines has been examined by MTT assay. The apoptosis assay was carried out with Acridine Orange (AO) staining methods and the results indicate that complexes can induce the apoptosis of HeLa cells. The cell cycle arrest investigated by flow cytometry and these results indicate that complexes 1-4 induce the cell cycle arrest at G0/G1

  18. Preparation of the GO/Pd nanocomposite and its application for the degradation of organic dyes in water.

    Science.gov (United States)

    Omidvar, Afshan; Jaleh, Babak; Nasrollahzadeh, Mahmoud

    2017-06-15

    A GO/Pd nanocomposite has been successfully synthesized applying a simple method via immobilizing Pd on the surface of the graphene oxide (GO). The GO/Pd nanocomposite was characterized by X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) spectroscopy, Raman, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques. The surface morphology of Pd NPs was viewed by TEM, the particles are spherical with an average particle size of 11nm. The catalytic activity of the GO/Pd nanocomposite is excellent for the degradation of organic dyes such as Congo red (CR), methylene blue (MB) and methyl orange (MO) in the presence of NaBH4 in aqueous media at room temperature. For the first time, the degradation of CR, MB and MO was reported using GO/Pd nanocomposite as a heterogeneous catalyst. The excellent catalytic effect for the degradation of dyes was monitored by UV-visible spectroscopy at regular time intervals. When GO/Pd nanocomposite was added into the solution containing dye and NaBH4, the intensity of the strong absorption peak gradually decreased and the whole peak disappeared. It followed the pseudo-first order reaction and time of the reduction reactions is short. In addition, the catalyst can be recovered and reused up to multiple runs without any marked loss in its catalytic activity.

  19. Preparation and Performances of RuO2/TiO2 Films Photocatalyst Supported on Float Pearls%RuO2/TiO2/漂珠复合光催化剂的制备及性能

    Institute of Scientific and Technical Information of China (English)

    姚秉华; 王理明; 王骋; 王逸迅; 赵高阳

    2007-01-01

    利用RuO2/TiO2前驱体溶胶,采用溶胶-凝胶-浸渍法在漂珠(FP)表面沉积RuO2/TiO2膜,经120℃干燥、500℃焙烧制备复合光催化剂RuO2/TiO2/FP,并通过SEM、XRD以及FT-IR分别对其结构进行了表征.结果表明,RuO2/TiO2膜的平均厚度(三层)约1μm,膜材料中TiO2主要呈现锐钛矿型结构,而RuO2是以非晶态高度分散在粒子表面.以高效氯氰菊酯杀虫剂的光催化降解为模型反应,研究了RuO2/TiO2/FP的光催化性能,探讨了影响催化剂活性的因素及采用太阳光做光源处理BEC的可行性.实验表明,当RuO2/TiO2/FP用量为5 g/L、BEC初始浓度为45 mg/L、初始pH为6.5、通气量为200 mL/min,反应60 min,BEC降解率分别为88.1%(125 W高压汞灯,主波长365 nm)、82.8%(5W紫外灯,主波长256 nm)和75.1%(8 W日光灯).BEC的降解反应遵从L-H动力学模型,测得反应速率常数17.5 mg/(L min)和吸附常数3.48 L/g.%RuO2/TiO2 films were deposited on float pearls (FP) by the sol-gel-dipping method. The substrates were coated with RuO2/TiO2 precursor sol, air-dried at 120 ℃ and further heated at 500 ℃ to obtain the coupled photocatalyst of RuO2/TiO2 films supported on FP (RuO2/TiO2/FP). The structure of coupled photocatalyst was characterized by SEM, XRD, and FT-IR technique, respectively. The results showed TiO2 has anatase structure and doped RuO2 was highly dispersed on the surface of TiO2 particles as amorphous. The average thickness of RuO2/TiO2 films (3 layers) on FP was determined to be about 1 μm. This study was carried out under the following conditions: volume 60 mL, initial concentration of beta-cypermethrin (BEC) 45 mg/L, pH 6.5, amount of RuO2/TiO2/PF 5 g/L, air flow rate 200 mL/min, reaction time 60 min.The degradation rates of BEC are 88.1% (125 W Hg lamp), 82.8% (8 W UV lamp), and 75.1% (8 W solar lamp), respectively. The photocatalytic degradation of BEC was experimentally demonstrated to follow the Langmuir-Hinshelwood kinetic model, and the

  20. Dissociative sticking of CH4 on Ru(0001)

    DEFF Research Database (Denmark)

    Nielsen, Jane Hvolbæk; Holmblad, Peter Mikal; Chorkendorff, Ib

    1999-01-01

    In this study the CH4 dissociation probability on Ru(0001) is found for various translational and vibrational energies. The absolute sticking values are determined from King and Wells experiments and carbon uptake curves. The carbon amount is determined from the recombination signal of carbon...... with oxygen obtained after the beam exposure when heating in an oxygen atmosphere. The measured sticking coefficient of CH4 is strongly enhanced both by increasing the translational and the vibrational energy of the CH4 molecule. A model is applied to the data and an estimate of the thermal activation energy...

  1. Triaxiality near the 110Ru ground state from Coulomb excitation

    Science.gov (United States)

    Doherty, D. T.; Allmond, J. M.; Janssens, R. V. F.; Korten, W.; Zhu, S.; Zielińska, M.; Radford, D. C.; Ayangeakaa, A. D.; Bucher, B.; Batchelder, J. C.; Beausang, C. W.; Campbell, C.; Carpenter, M. P.; Cline, D.; Crawford, H. L.; David, H. M.; Delaroche, J. P.; Dickerson, C.; Fallon, P.; Galindo-Uribarri, A.; Kondev, F. G.; Harker, J. L.; Hayes, A. B.; Hendricks, M.; Humby, P.; Girod, M.; Gross, C. J.; Klintefjord, M.; Kolos, K.; Lane, G. J.; Lauritsen, T.; Libert, J.; Macchiavelli, A. O.; Napiorkowski, P. J.; Padilla-Rodal, E.; Pardo, R. C.; Reviol, W.; Sarantites, D. G.; Savard, G.; Seweryniak, D.; Srebrny, J.; Varner, R.; Vondrasek, R.; Wiens, A.; Wilson, E.; Wood, J. L.; Wu, C. Y.

    2017-03-01

    A multi-step Coulomb excitation measurement with the GRETINA and CHICO2 detector arrays was carried out with a 430-MeV beam of the neutron-rich 110Ru (t1/2 = 12 s) isotope produced at the CARIBU facility. This represents the first successful measurement following the post-acceleration of an unstable isotope of a refractory element. The reduced transition probabilities obtained for levels near the ground state provide strong evidence for a triaxial shape; a conclusion confirmed by comparisons with the results of beyond-mean-field and triaxial rotor model calculations.

  2. Helium, neon and argon diffraction from Ru(0001).

    Science.gov (United States)

    Minniti, M; Díaz, C; Fernández Cuñado, J L; Politano, A; Maccariello, D; Martín, F; Farías, D; Miranda, R

    2012-09-05

    We present an experimental and theoretical study of He, Ne and Ar diffraction from the Ru(0001) surface. Close-coupling calculations were performed to estimate the corrugation function and the potential well depth in the atom-surface interaction in all three cases. DFT (density functional theory) calculations, including van der Waals dispersion forces, were used to validate the close-coupling results and to further analyze the experimental results. Our DFT calculations indicate that, in the incident energy range 20-150 meV, anticorrugating effects are present in the case of He and Ar diffraction, whereas normal corrugation is observed with Ne beams.

  3. Comparing Ru and Fe-catalyzed olefin metathesis

    KAUST Repository

    Poater, Albert

    2014-01-01

    Density functional theory calculations have been used to explore the potential of Fe-based complexes with an N-heterocyclic carbene ligand, as olefin metathesis catalysts. Apart from a less endothermic reaction energy profile, a small reduction in the predicted upper energy barriers (≈ 2 kcal mol -1) is calculated in the Fe catalyzed profile with respect to the Ru catalysed profile. Overall, this study indicates that Fe-based catalysts have the potential to be very effective olefin metathesis catalysts. This journal is © the Partner Organisations 2014.

  4. Is the methanation reaction over Ru single crystals structure dependent?

    DEFF Research Database (Denmark)

    Vendelbo, Søren Bastholm; Johansson, Martin; Nielsen, Jane Hvolbæk;

    2011-01-01

    The influence of monoatomic steps and defects on the methanation reaction over ruthenium has been investigated. The experiments are performed on a Ru(0 1 54) ruthenium single crystal, which contains one monoatomic step atom for each 27 terrace atoms. The methanation activity is measured at one ba...... front-side of the crystal is poisoned faster than the entire crystal containing more defects. We also observe that additional sputtering of the well-defined front-side increases the reactivity measured on the surface. Based on this, we conclude that the methanation reaction takes place...

  5. Extended collective bands in neutron-rich 109Ru

    Institute of Scientific and Technical Information of China (English)

    DING Huai-Bo; ZHU Sheng-Jiang; J.H. Hamilton; A.V. Ramayya; J. K. Hwang; K. Li; S.H. Liu; Y.X. Luo; J.O. Rasmussen; C.T. Goodin; I. Y. Lee; WANG Jian-Guo; CHE Xing-Lai; GU Long

    2009-01-01

    Levels in the neutron-rich 109Ru have been studied by observing the prompt γ-rays following the spontaneous fission fragments of 252Cf. The ground state band and the negative parity bands have been confirmed and extended. A positive parity band with the band head level at 332.5 keV is newly identified and suggested as a single-neutron excitation band built on the 7/2+ [404] Nilsson orbital. Some structural characteristics of these bands are discussed.

  6. THz-Pulse-Induced Selective Catalytic CO Oxidation on Ru

    Science.gov (United States)

    LaRue, Jerry L.; Katayama, Tetsuo; Lindenberg, Aaron; Fisher, Alan S.; Ã-ström, Henrik; Nilsson, Anders; Ogasawara, Hirohito

    2015-07-01

    We demonstrate the use of intense, quasi-half-cycle THz pulses, with an associated electric field component comparable to intramolecular electric fields, to direct the reaction coordinate of a chemical reaction by stimulating the nuclear motions of the reactants. Using a strong electric field from a THz pulse generated via coherent transition radiation from an ultrashort electron bunch, we present evidence that CO oxidation on Ru(0001) is selectively induced, while not promoting the thermally induced CO desorption process. The reaction is initiated by the motion of the O atoms on the surface driven by the electric field component of the THz pulse, rather than thermal heating of the surface.

  7. PD-1/PD-L1 expression in chromophobe renal cell carcinoma: An immunological exception?

    Science.gov (United States)

    Erlmeier, Franziska; Hartmann, Arndt; Autenrieth, Michael; Wiedemann, Max; Ivanyi, Philipp; Steffens, Sandra; Weichert, Wilko

    2016-11-01

    Immune checkpoint inhibitors targeting the inhibitory cross talk between tumor and immune cells have been approved for therapy in renal cell carcinoma (RCC). In contrast to clear cell RCC, little is known on PD-1/PD-L1 expression patterns in rarer RCC subtypes. The aim of this study was to evaluate the prevalence, distribution and prognostic impact of PD-1 and PD-L1 expression in chromophobe (ch)RCC. Patients who underwent renal surgery due to chRCC were retrospectively evaluated. Tumor specimen was analyzed for PD-1 and PD-L1 expression by immunohistochemistry. Expression data were correlated with clinic-pathological parameters including patient survival. Eighty-one chRCC patients were eligible for analysis, thereof 25 (30.9 %) and 11 (13.6 %) patients were positive for PD-1(+) tumor-infiltrating mononuclear cells (TIMCs) and tumoral PD-L1(+) expression, respectively. No significant associations were found for PD-1(+) TIMC or tumoral PD-L1(+) expression and clinical attributes. In addition, no differences in 5- and 10-year overall survival for PD-1(-) TIMC compared to PD-1(+) TIMC (90.5 and 72.2 vs. 100 and 75 %; p = 0.41) and for PD-L1(-) tumors compared to PD-L1(+) tumors (91.9 and 76.4 vs. 100 and 50 %; p = 0.48) were observed. In conclusion, to our knowledge this is the first study to evaluate the prognostic impact of PD-1 and PD-L1 in chRCC. PD-L1 does seem to be expressed in a minority of all chRCC, likewise only a minority of chRCC was infiltrated by PD-1-positive inflammatory cells. Neither PD-1(+) TIMC nor tumoral PD-L1(+) expression was associated with parameters of aggressiveness or survival.

  8. Preparation of (103)Pd brachytherapy seeds by electroless plating of (103)Pd onto carbon bars.

    Science.gov (United States)

    Li, Zhong-Yong; Gao, Hui-Bo; Deng, Xue-Song; Zhou, Leng; Zhang, Wen-Hui; Han, Lian-Ge; Jin, Xiao-Hai; Cui, Hai-Ping

    2015-09-01

    A method for preparing (103)Pd brachytherapy seeds is reported. The key of the method was to deposit (103)Pd onto carbon bars by electroless plating so as to prepare source cores. After each carbon bar with (103)Pd was sealed in a titanium capsule, the (103)Pd seeds were fabricated. This paper provides valuable experiences and data for the preparation of (103)Pd brachytherapy seeds.

  9. Tungsten carbide promoted Pd and Pd-Co electrocatalysts for formic acid electrooxidation

    Science.gov (United States)

    Yin, Min; Li, Qingfeng; Jensen, Jens Oluf; Huang, Yunjie; Cleemann, Lars N.; Bjerrum, Niels J.; Xing, Wei

    2012-12-01

    Tungsten carbide (WC) promoted palladium (Pd) and palladium-cobalt (Pd-Co) nanocatalysts are prepared and characterized for formic acid electrooxidation. The WC as the dopant to carbon supports is found to enhance the CO tolerance and promote the activity of the Pd-based catalysts for formic acid oxidation. Alloying of Pd with Co further improves the electrocatalytic activity and stability of the WC supported catalysts, attributable to a synergistic effect of the carbide support and PdCo alloy nanoparticles.

  10. Investigation of Novel Electrocatalysts for Metal Supported Solid Oxide Fuel Cells - Ru:GDC

    DEFF Research Database (Denmark)

    Sudireddy, Bhaskar Reddy; Nielsen, Jimmy; Thydén, Karl Tor Sune

    2015-01-01

    The electrochemical performance and stability of the planar metal supported solid oxide fuel cells (MS-SOFC) with two different electrocatalytically active materials, namely, Ni:GDC and Ru:GDC were investigated. Ru:GDC with an ASR of 0.322 Ωcm2 performed better than Ni:GDC with an ASR of 0.453 Ωc...

  11. Lutidine-derived Ru-CNC hydrogenation pincer catalysts with versatile coordination properties

    NARCIS (Netherlands)

    Filonenko, Georgy A.; Cosimi, Elena; Lefort, Laurent; Conley, Matthew P.; Copéret, Christophe; Lutz, Martin|info:eu-repo/dai/nl/304828971; Hensen, Emiel J M; Pidko, Evgeny A.

    2014-01-01

    Lutidine-derived bis-N-heterocyclic carbene (NHC) ruthenium CNC-pincer complexes (Ru-CNC's) were prepared. Depending on the synthetic procedure, normal (1, 2) or mixed normal/abnormal NHC-complexes (3) are formed. In the presence of phosphazene base, Ru-CNC complexes activate nitriles to give ketimi

  12. A PHARMACOKINETIC STUDY ON RU 486 AND ITS METABOLITES AFTER ORAL ADMINISTRATION AT VARIOUS DOSES

    Institute of Scientific and Technical Information of China (English)

    SHIYong-En; YEZhi-Hou; HEChang-Hai; ZHANGGuo-Qin; XUJian-Qiu; BAJXiu-Mei

    1989-01-01

    The purpose of the present study is to obtain pharmacokinetic parameters of RU486 and its metabolites and then to find out an optimal regimen of the compound for termination of human early pregnancy. Plasma levels of RU486 and its metabolites,

  13. Lutidine-derived Ru-CNC hydrogenation pincer catalysts with versatile coordination properties

    NARCIS (Netherlands)

    Filonenko, Georgy A.; Cosimi, Elena; Lefort, Laurent; Conley, Matthew P.; Copéret, Christophe; Lutz, Martin; Hensen, Emiel J M; Pidko, Evgeny A.

    2014-01-01

    Lutidine-derived bis-N-heterocyclic carbene (NHC) ruthenium CNC-pincer complexes (Ru-CNC's) were prepared. Depending on the synthetic procedure, normal (1, 2) or mixed normal/abnormal NHC-complexes (3) are formed. In the presence of phosphazene base, Ru-CNC complexes activate nitriles to give ketimi

  14. Hydrothermal Synthesis of Co-Ru Alloy Particle Catalysts for Hydrogen Generation from Sodium Borohydride

    Directory of Open Access Journals (Sweden)

    Marija Kurtinaitienė

    2013-01-01

    Full Text Available We report the synthesis of μm and sub-μm-sized Co, Ru, and Co-Ru alloy species by hydrothermal approach in the aqueous alkaline solutions (pH ≥ 13 containing CoCl2 and/or RuCl3, sodium citrate, and hydrazine hydrate and a study of their catalytic properties for hydrogen generation by hydrolysis of sodium borohydride solution. This way provides a simple platform for fabrication of the ball-shaped Co-Ru alloy catalysts containing up to 12 wt% Ru. Note that bimetallic Co-Ru alloy bowls containing even 7 at.% Ru have demonstrated catalytic properties that are comparable with the ones of pure Ru particles fabricated by the same method. This result is of great importance in view of the preparation of cost-efficient catalysts for hydrogen generation from borohydrides. The morphology and composition of fabricated catalyst particles have been characterized using scanning electron microscopy, energy dispersive X-ray diffraction, and inductively coupled plasma optical emission spectrometry.

  15. Adsorption properties of CoPc molecule on epitaxial graphene/Ru(0 0 0 1)

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yiliang; Zhang, Hanjie; Song, Junjie; Zhang, Yuxi; Bao, Shining; He, Pimo, E-mail: phypmhe@zju.edu.cn

    2015-02-01

    Graphical abstract: - Highlights: • The adsorption behavior of CoPc on MG/Ru(0 0 0 1) was investigated by STM and DFT. • The impact of the defect in MG/Ru(0 0 0 1) on the adsorption properties was studied. • A central contrast was found for CoPcs adsorbed on intact and defective graphene. - Abstract: Combining the scanning tunneling microscopy (STM) and density functional theory (DFT), the adsorption properties of cobalt phthalocyanine (CoPc) on monolayer graphene/Ru(0 0 0 1) [MG/Ru(0 0 0 1)] have been investigated. At monolayer coverage, CoPc forms an ordered Kagome lattice, and a slight deformation for one lobe of CoPc and charge transfer from CoPc to Ru(0 0 0 1) substrate take place. The existence of the defect (vacancy) in graphene on Ru(0 0 0 1) increases the coupling between the Ru substrate and the epitaxial graphene. Such an increase of the coupling brings about an overall CoPc molecular energy level shift toward the low binding energy, which subsequently results in a central topographical contrast between the CoPc molecules on the intact and defective MG/Ru(0 0 0 1)

  16. Superconductivity at 3.1 K in the orthorhombic ternary silicide ScRuSi

    Science.gov (United States)

    Ruan, Bin-Bin; Wang, Xiao-Chuan; Yu, Jia; Pan, Bo-Jin; Mu, Qing-Ge; Liu, Tong; Chen, Gen-Fu; Ren, Zhi-An

    2017-02-01

    We report the synthesis, crystal structure, superconductivity and physical property characterizations of the ternary equiatomic compound ScRuSi. Polycrystalline samples of ScRuSi were prepared by an arc-melting method. The as-prepared samples were identified as the orthorhombic Co2P-type o-ScRuSi by powder x-ray diffraction analysis. Electrical resistivity measurements show o-ScRuSi to be a metal which superconducts below a T c of 3.1 K; the upper critical field μ 0 H c2(0) is estimated to be 0.87 T. The magnetization and specific heat measurements confirm the bulk type-II superconductivity in o-ScRuSi, with a specific heat jump within the BCS weak coupling limit. o-ScRuSi is the first Co2P-type superconductor to contain scandium. After annealing at 1273 K for a week, o-ScRuSi transforms into hexagonal Fe2P-type h-ScRuSi, which is a Pauli-paramagnetic metal with no superconductivity observed above 1.8 K.

  17. PtRu colloid nanoparticles for CO oxidation in microfabricated reactors

    DEFF Research Database (Denmark)

    Klerke, Asbjørn; Saadi, Souheil; Toftegaard, Maja Bøg

    2006-01-01

    The catalytic activity of PtRu colloid nanoparticles for CO oxidation is investigated in microfabricated reactors. The measured catalytic performance describes a volcano curve as a function of the Pt/Ru ratio. The apparent activation energies for the different alloy catalysts are between 21 and 117...

  18. Ru alkylidene compounds bearing tridentate, dianionic ligands: Lewis acid activation and olefin metathesis.

    Science.gov (United States)

    McKinty, Adam M; Stephan, Douglas W

    2016-03-01

    The series of tridentate complexes of Ru-alkylidenes (L)Ru(CHPh)(SCH2CH2)2E (E = O, L = SIMes 1, PCy3 2, E = S, L = SIMes 3, PCy3 4; E = PPh 7, L = PCy3), (L)Ru(CHPh)(SC6H4)2S (L = SIMes 5, PCy3 6), (L)Ru(CHPh) (OCH2CH2)2O (L = SIMes 8, PCy3 9) were prepared and shown to react with one equivalent of BCl3 to give the complexes (L)Ru(CHPh)Cl[E(CH2CH2S)2BCl2] (E = O, L = SIMes 10, PCy3 11, E = S, L = SIMes 12a/b, PCy3 13, E = PPh, L = PCy3 16) and (L)Ru(CHPh)(SC6H4)2O (L = SIMes 14, PCy3 15). In the case of 1 and 2 reaction with two equivalents of BCl3 affording the corresponding cation via chloride abstraction. These cations coordinate MeCN to give the six coordinate Ru cation salts [(L)Ru(CHPh)- (NCMe)(O(CH2CH2S)2BCl2)][BCl4] L = SIMes 17, PCy3 18). The generated five coordinate cations derived from 2-9 via addition of two equivalents of BCl3 were evaluated in standard preliminary tests for olefin metathesis catalysis.

  19. The formation mechanism of bimetallic PtRu alloy nanoparticles in solvothermal synthesis.

    Science.gov (United States)

    Mi, Jian-Li; Nørby, Peter; Bremholm, Martin; Becker, Jacob; Iversen, Bo B

    2015-10-21

    An understanding of the nucleation and growth mechanism of bimetallic nanoparticles in solvothermal synthesis is important for further development of nanoparticles with tailored nanostructures and properties. Here the formation of PtRu alloy nanoparticles in a solvothermal synthesis using metal acetylacetonate salts as precursors and ethanol as both the solvent and reducing agent has been studied by in situ synchrotron radiation powder X-ray diffraction (SR-PXRD). Unlike the classical mechanism for the synthesis of monodisperse sols, the nucleation and growth processes of bimetallic PtRu nanoparticles occur simultaneously under solvothermal conditions. In the literature co-reduction of Pt and Ru is often assumed to be required to form PtRu bimetallic nanocrystals, but it is shown that monometallic Pt nanocrystals nucleate first and rapidly grow to an average size of 5 nm. Subsequently, the PtRu bimetallic alloy is formed in the second nucleation stage through a surface nucleation mechanism related to the reduction of Ru. The calculated average crystallite size of the resulting PtRu nanocrystals is smaller than that of the primary Pt nanocrystals due to the large disorder in the PtRu alloyed structure.

  20. Lutidine-derived Ru-CNC hydrogenation pincer catalysts with versatile coordination properties

    NARCIS (Netherlands)

    Filonenko, Georgy A.; Cosimi, Elena; Lefort, Laurent; Conley, Matthew P.; Copéret, Christophe; Lutz, Martin|info:eu-repo/dai/nl/304828971; Hensen, Emiel J M; Pidko, Evgeny A.

    2014-01-01

    Lutidine-derived bis-N-heterocyclic carbene (NHC) ruthenium CNC-pincer complexes (Ru-CNC's) were prepared. Depending on the synthetic procedure, normal (1, 2) or mixed normal/abnormal NHC-complexes (3) are formed. In the presence of phosphazene base, Ru-CNC complexes activate nitriles to give

  1. Electrocatalytic activity of atomic layer deposited Pt–Ru catalysts onto N-doped carbon nanotubes

    DEFF Research Database (Denmark)

    Johansson, Anne-Charlotte Elisabeth Birgitta; Larsen, Jackie Vincent; Verheijen, Marcel A.

    2014-01-01

    (ethylcyclopentadienyl)ruthenium (Ru(EtCp)2), respectively. O2 was used as the reactant in both processes. The composition of the catalysts was easily tuned by varying the Pt-to-Ru ALD cycle ratio. The catalysts were tested toward the CO oxidation and methanol oxidation reaction (MOR) in a three-electrode electrochemical set...

  2. EFFECT OF RU486 ON THE LUTEAL FUNCTION IN THE PREGNANT MOUSE

    Institute of Scientific and Technical Information of China (English)

    LIShu-Xiang; GUDun-Yu; WUXiao-Yun; ZHUJian-Yu; JIANGWen-Jue; SUNPei-Long; YANGYi-Qian

    1989-01-01

    The effect of RU486, an antiprogestin, on luteal functions in the post-implantation mouse was studied. (1) In vivo experiment: Female adult mice were treated with RU486 at an oral dose of 100 mg/kg on day 1 and day 2 of pregnancy. Autopsy was performed

  3. RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

    National Research Council Canada - National Science Library

    Wade Lonsdale; Magdalena Wajrak; Kamal Alameh

    2017-01-01

    A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor...

  4. Photoluminescence quenching of [Ru(bpy)2(atatp)](2+) bound to a condensed DNA matrix.

    Science.gov (United States)

    Chen, Linlin; Chao, Hui; Zhao, Qianwen; Zheng, Xuling; Li, Hong

    2016-01-01

    A novel [Ru(bpy)2(atatp)](2+) (bpy=2,2'-bipyridine and atatp=acenaphtheno[1,2-b]-1,4,8,9-tetraazatriphenylene) can induce the condensation of herring sperm DNA to form an orange-red cast film via intercalation and electrostatic attraction. The thus-prepared cast film shows microsecond emission lifetimes and reversible luminescence tuning characteristics by oxygen and nitrogen with an on-off emission intensity ratio of 4.3. The photoluminescence of [Ru(bpy)2(atatp)](2+) bound to a DNA condensed matrix can be quenched by water, dissolved oxygen, copper(II) and ferrocyanide ions. The DNA binding is found to hardly alter the dynamic quenching of [Ru(bpy)2(atatp)](2+) by oxygen at a low DNA-to-Ru(II) molar ratio (r=0.83), allowing [Ru(bpy)2(atatp)](2+) to keep a basically unchanged oxygen quenching constant, as well as endow the photo-induced electron transfer between [Ru(bpy)2(atatp)](2+) and copper(II) cations, and weaken the electrostatic attraction of [Ru(bpy)2(atatp)](2+) with ferrocyanide anions. In addition, the DNA condensation induced by [Ru(bpy)2(atatp)](2+) can protect the DNA oxidative damage against superoxide anion and hydroxyl radical toxicity. The present results could provide a versatile platform for better fabrication of optoelectronic devices.

  5. Anisotropic Ru3 + 4 d5 magnetism in the α -RuCl3 honeycomb system: Susceptibility, specific heat, and zero-field NMR

    Science.gov (United States)

    Majumder, M.; Schmidt, M.; Rosner, H.; Tsirlin, A. A.; Yasuoka, H.; Baenitz, M.

    2015-05-01

    Hexagonal α -Ru trichloride single crystals exhibit a strong magnetic anisotropy and we show that upon applying fields up to 14 T in the honeycomb plane the successive magnetic order at T1=14 K and T2=8 K could be completely suppressed, whereas in the perpendicular direction the magnetic order is robust. Furthermore, the field dependence of χ (T ) implies coexisting ferro- and antiferromagnetic exchange between in-plane components of Ru3+ spins, whereas for out-of-plane components a strong antiferromagnetic exchange becomes evident. 101Ru zero-field nuclear magnetic resonance in the ordered state evidence a complex (probably noncoplanar chiral) long-range magnetic structure. The large orbital moment on Ru3 + is found in density-functional calculations.

  6. Low leakage Ru-strontium titanate-Ru metal-insulator-metal capacitors for sub-20 nm technology node in dynamic random access memory

    Energy Technology Data Exchange (ETDEWEB)

    Popovici, M., E-mail: Mihaela.Ioana.Popovici@imec.be; Swerts, J.; Redolfi, A.; Kaczer, B.; Aoulaiche, M.; Radu, I.; Clima, S.; Everaert, J.-L.; Van Elshocht, S.; Jurczak, M. [Imec, Leuven 3001 (Belgium)

    2014-02-24

    Improved metal-insulator-metal capacitor (MIMCAP) stacks with strontium titanate (STO) as dielectric sandwiched between Ru as top and bottom electrode are shown. The Ru/STO/Ru stack demonstrates clearly its potential to reach sub-20 nm technology nodes for dynamic random access memory. Downscaling of the equivalent oxide thickness, leakage current density (J{sub g}) of the MIMCAPs, and physical thickness of the STO have been realized by control of the Sr/Ti ratio and grain size using a heterogeneous TiO{sub 2}/STO based nanolaminate stack deposition and a two-step crystallization anneal. Replacement of TiN with Ru as both top and bottom electrodes reduces the amount of electrically active defects and is essential to achieve a low leakage current in the MIM capacitor.

  7. Highly (110)- and (111)-oriented BiFeO3 films on BaPbO3 electrode with Ru or Pt /Ru barrier layers

    Science.gov (United States)

    Lee, Chia-Ching; Wu, Jenn-Ming; Hsiung, Chang-Po

    2007-04-01

    Highly (110)- and (111)-oriented BiFeO3 (BFO) films were fabricated with BaPbO3 (BPO )/Ru and BPO /Pt/Ru as electrode/barrier on Si substrates by rf-magnetron sputtering. The BPO /Ru and BPO /Pt/Ru stacks both induce oriented BFO films and act as diffusion barriers. The (110)- and (111)-oriented BFO films possess excellent ferroelectric properties with only minor leakage. The values of remnant polarization are almost the same, about 42μC/cm2, for (110)- and (111)-oriented BFO films. However, polarization measured under varying pulse widths demonstrates that the switching polarization in (111)-oriented BFO films is higher than in (110)-oriented films. Additionally, (111)-oriented BFO films exhibit better retention properties than (110)-oriented films.

  8. RuO2/Ru/TiO2光催化剂制备及模拟太阳光催化产氢

    Institute of Scientific and Technical Information of China (English)

    刘海波; 阎建辉

    2009-01-01

    采用浸渍-氢气还原法制备了RuO2/Ru/TiO2光催化剂,并采用XRD、SEM、UV-vis漫反射光谱和荧光光谱(FS)等手段对样品进行了表征,以草酸为电子给体,研究了RuO2的负载量对P25-TiO2光催化产氢活性的影响。结果表明,P25-TiO2表面负载RuO2大大地提高了其光催化产氢速度,模拟太阳光下2wt%负载量下达到最佳产氢活性,6h内的产氢量达到45mmol。

  9. IR Thermography NDE of ISS Radiator Panels

    Science.gov (United States)

    Koshti, Ajay; Winfree, William; Morton, Richard; Wilson, Walter; Reynolds, Gary

    2010-01-01

    The presentation covers an active and a passive infrared (IR) thermography for detection of delaminations in the radiator panels used for the International Space Station (ISS) program. The passive radiator IR data was taken by a NASA astronaut in an extravehicular activity (EVA) using a modified FLIR EVA hand-held camera. The IR data could be successfully analyzed to detect gross facesheet disbonds. The technique used the internal hot fluid tube as the heat source in analyzing the IR data. Some non-flight ISS radiators were inspected using an active technique of IR flash thermography to detect disbond of face sheet with honeycomb core, and debonds in facesheet overlap areas. The surface temperature and radiated heat emission from flight radiators is stable during acquisition of the IR video data. This data was analyzed to detect locations of unexpected surface temperature gradients. The flash thermography data was analyzed using derivative analysis and contrast evolutions. Results of the inspection are provided.

  10. High Molar Extinction Coefficient Ru(II-Mixed Ligand Polypyridyl Complexes for Dye Sensitized Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Malapaka Chandrasekharam

    2011-01-01

    Full Text Available Two new ruthenium(II mixed ligand terpyridine complexes, “Ru(Htcterpy(NCS(L1 (N(C4H94, mLBD1” and Ru(Htcterpy(NCS(L2(N(C4H94, mLBD2 were synthesized and fully characterized by UV-Vis, emission, cyclic voltammogram, and other spectroscopic means, and the structures of the compounds are confirmed by 1H-NMR, ESI-MASS, and FT-IR spectroscopes. The influence of the substitution of L1 and L2 on solar-to-electrical energy conversion efficiency (η of dye-sensitized solar cells (DSSCs was evaluated relative to reference black dye. The dyes showed molar extinction coefficients of 17600 M−1 cm−1 for mLBD1 and 21300 M−1 cm−1 for mLBD2 both at λ maximum of 512 nm, while black dye has shown 8660 M−1 cm−1 at λ maximum of 615 nm. The monochromatic incident photon-to-collected electron conversion efficiencies of 60.71% and 75.89% were obtained for mLBD1 and mLBD2 dyes, respectively. The energy conversion efficiencies of mLBD1 and mLBD2 dyes are 3.15% (SC=11.86 mA/cm2, OC=613 mV, ff=0.4337 and 3.36% (SC=12.71 mA/cm2, OC=655 mV, ff=0.4042, respectively, measured at the AM1.5G conditions, the reference black dye-sensitized solar cell, fabricated and evaluated under identical conditions exhibited η-value of 2.69% (SC=10.95 mA/cm2, OC=655 mV, ff=0.3750.

  11. Angle-integrated photoemission studies of ruthocuprate Eu_2-xCe_xRuSr_2Cu_2O_10, Gd_2RuSr_2Cu_2O_10 and Eu_1.5Nb_1-xRu_xCu_2O_10 systems

    Science.gov (United States)

    Frazer, B.; Hirai, Y.; Rast, Simon; Felner, I.; Asaf, U.; Onellion, M.

    2000-03-01

    We report on both resonant photoemission and fixed photon energy studies of the conduction band and core levels for several ruthocuprate systems. The pure Ru-containing compounds exhibit ferromagnetic order, with metallic behavior and superconductivity depending on the rare earth and oxygen content. We report on as-prepared, hydrogen loaded, and oxygen-annealed polycrystalline samples. The Nb-Ru series changes from purely superconducting to both ferromagnetic and superconducting (Ru). The resonant photoemission measurements of the conduction band across the Ru4p, Cu3p, and Eu4d core levels allow us to determine the location and contribution of Ru, Cu and rare earth related states in the conduction band. The O1s, Cu2p, Ru3p, Ce4d, and Gd4d and several Nb core levels allow us to determine the valence of Ru and Nb, and the metallicity of the Ru/Nb, rare earth, and CuO2 planes.

  12. Particle Size Effect of Ru-Zn Catalysts on Selective Hydrogenation of Benzene to Cyclohexene†%Ru-Zn 催化剂在苯选择加氢制环己烯反应中的粒径效应

    Institute of Scientific and Technical Information of China (English)

    孙海杰; 陈凌霞; 黄振旭; 刘寿长; 刘仲毅

    2015-01-01

    Ru-Zn catalysts modified by water soluble polymers were prepared by a precipitation method. The catalysts after hydrogenation were characterized by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy and N2 physisorption. It was found that the type of water-soluble polymers and the dosage of PEG-20000 imposed a remarkable effect on the particle size of Ru. With the Ru particle size in Ru-Zn catalysts increasing, benzene conversion decreased, and the maximum cyclohexene yield showed a volcanic-type variation tendency. When the Ru particle size of the Ru-Zn catalyst modified by 0. 4 g PEG[ m( PEG-20000) : m( Ru) = 0. 2] was 4. 8 nm, a maximum cyclohexene yield of 62. 2% was obtained on this catalyst. The Ru particle size could produce an effect on the Zn / Ru atomic ratio on the catalyst surface, which was the primary reason why the Ru particle size could affect the performance of Ru-Zn catalysts.%采用共沉淀法制备了水溶性聚合物修饰的苯选择加氢制环己烯 Ru-Zn 催化剂,并用 X 射线衍射、透射电镜、 X 射线能量色散谱、 X 射线光电子能谱和氮气物理吸附等对加氢后催化剂进行了表征.结果表明,水溶性聚合物的种类和聚乙二醇-20000(PEG-20000)的用量对 Ru-Zn 催化剂微晶尺寸有显著影响.在 ZnSO4存在下,随着 Ru-Zn 催化剂 Ru 微晶尺寸增加,苯转化率降低,环己烯最高收率则呈火山型变化趋势.用0.4 g PEG-20000修饰的 Ru-Zn 催化剂[m(PEG-20000): m(Ru)=0.2]Ru 的微晶尺寸为4.8 nm,环己烯最高收率为62.2%. Ru 微晶尺寸影响催化剂表面的 Zn/ Ru 原子比,进而影响 Ru-Zn 催化剂性能.

  13. Oxidizing behavior of some platinum metal fluorides. [Xe complexes with Pt, Pd fluorides; Chlorine-2 oxidation by transition metal hexafluorides

    Energy Technology Data Exchange (ETDEWEB)

    Graham, L.

    1978-10-01

    The previously known compounds Xe/sub 2/F/sub 3//sup +/PtF/sub 6//sup -/, XeF/sup +/PtF/sub 6//sup -/ and XeF/sub 2/.2PtF/sub 4/(XePt/sub 2/F/sub 10/) were prepared by the interaction of XeF/sub 2/ with PtF/sub 4/. The new compounds XeF/sub 2/.PdF/sub 4/ and XeF/sub 2/.2PdF/sub 4/(XePd/sub 2/F/sub 10/) were produced by interaction of XeF/sub 2/ with either PdF/sub 4/ or Pd/sub 2/F/sub 6/. A weight loss-versus-time curve indicated the presence of 4:1, 3:1 and 2:1 XeF/sub 2//PdF/sub 4/ complexes. The thermal decomposition of XeFPtF/sub 6/ or XePd/sub 2/F/sub 10/ yields highly pure XeF/sub 4/. Thus the interaction of XeF/sub 2/ with platinum fluorides (PtF/sub 4/ or PtF/sub 5/) or palladium fluorides (Pd/sub 2/F/sub 6/ or PdF/sub 4/) provides for the conversion of XeF/sub 2/ to XeF/sub 4/. The compound XePd/sub 2/F/sub 10/ is a close structural relative of XePt/sub 2/F/sub 10/, and spectroscopic evidence suggests that both are salts of XeF/sup +/ and a polymeric (M/sub 2/F/sub 9/)/sub x//sup x-/ ion. A Xe:PtF/sub 6/ material of approximately 1:1 stoichiometry has been prepared and compared with XePdF/sub 6/(XeF/sub 2/.PdF/sub 4/). The interaction of chlorine with the third-series transition metal hexafluorides has been investigated. Gravimetric and tensimetric evidence indicate that the initial product of the Cl/sub 2/ plus IrF/sub 6/ reaction is a solid of composition Cl/sub 2/IrF/sub 6/. Vibrational spectroscopic and other evidence indicates that this solid yields a sequence of products, of which Cl/sub 3//sup +/IrF/sub 6//sup -/, Cl/sub 3//sup +/Ir/sub 2/F/sub 11//sup -/ and Ir/sub 4/F/sub 20/ have been identified, the last being the ultimate solid product of the room temperature decomposition of the adduct. A new chlorine fluoride generated in the room temperature decomposition of Cl/sub 2/IrF/sub 6/ has been tentatively formulated as Cl/sub 3/F from infrared evidence.

  14. Tradicionālo tūrisma aģentūru un interneta ceļojumu rezervēšanas sistēmu salīdzinājums.

    OpenAIRE

    Šica, Anete

    2014-01-01

    Darba nosaukums ir „Tradicionālo tūrisma aģentūru un interneta ceļojumu rezervēšanas sistēmu salīdzinājums”. Darba mērķis ir apkopot un salīdzināt informāciju par tūrisma produktu iegādes veidiem, izstrādājot ieteikumus tradicionālo ceļojumu aģentūru tālākai pastāvēšanai tehnoloģiju laikmetā. Darbs sastāv no ievada, trīs nodaļām ar apakšnodaļām, secinājumiem, priekšlikumiem, izmantotās literatūras saraksta un pielikumiem. Darba galvenie literatūras avoti ir: populārzinātniskie raksti, z...

  15. Magnetic behavior of metallic kagome lattices, Tb3Ru4Al12 and Er3Ru4Al12

    Science.gov (United States)

    Upadhyay, Sanjay Kumar; Iyer, Kartik K.; Sampathkumaran, E. V.

    2017-08-01

    We report the magnetic behavior of two intermetallic-based kagome lattices, Tb3Ru4Al12 and Er3Ru4Al12, crystallizing in the Gd3Ru4Al2-type hexagonal crystal structure, by measurements in the range 1.8-300 K with bulk experimental techniques (ac and dc magnetization, heat capacity, and magnetoresistance). The main finding is that the Tb compound, known to order antiferromagnetically below (T N =) 22 K, shows glassy characteristics at lower temperatures (\\ll 15 K), thus characterizing this compound as a re-entrant spin-glass. The data reveal that the glassy phase is quite complex and is of a cluster type. Since glassy behavior was not seen for the Gd analog in the past literature, this finding on the Tb compound emphasizes that this kagome family could provide an opportunity to explore the role of higher-order interactions (such as quadrupole) in bringing out magnetic frustration. Additional findings reported here for this compound are: (i) The plots of temperature dependence of magnetic susceptibility and electrical resistivity data in the range 12-20 K, just below T N , are found to be hysteretic leading to a magnetic phase in this intermediate temperature range, mimicking disorder-broadened first-order magnetic phase transitions; (ii) features attributable to an interesting magnetic phase co-existence phenomenon in the isothermal magnetoresistance in zero field, after travelling across metamagnetic transition fields, are observed. With respect to the Er compound, we do not find any evidence for long-range magnetic ordering down to 2 K, but this compound appears to be on the verge of magnetic order at 2 K.

  16. How to remedy Eurocentrism in IR?

    DEFF Research Database (Denmark)

    Bilgin, Pinar

    2016-01-01

    While IR's Eurocentric limits are usually acknowledged, what those limits mean for theorizing about the international is seldom clarified. In The Global Transformation, Buzan and Lawson offer a 'composite approach' that goes some way towards addressing IR's Eurocentrism, challenging existing myth...... helps us recognize what is missing from IR theorizing - conceptions of the international by 'others' who also constitute the international. I illustrate this point by focussing on a landmark text on Ottoman history, Ortayll's The Longest Century of the Empire....

  17. IR properties of AGN and SB

    Science.gov (United States)

    Talezade Lari, M. H.; Davoudifar, P.; Mickaelian, A. M.

    2016-09-01

    Through multi-wavelength flux ratios it is possible to detect AGN and Star-burst Galaxies. Techniques of detecting extragalactic objects as well as AGN are studied in different wavelengths (X-Ray, Radio and IR). Specification of AGN as IR and radio sources is discussed. IR catalogues of 2MASS and WISE were used to study the interrelationship between interactions/merging, starburst and AGN phenomena.

  18. Characterisation and catalytic properties of Ni, Co, Ce and Ru nanoparticles in mesoporous carbon spheres

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Francisco A. A. [Universidade Federal do Ceara, Departamento de Quimica Analitica e Fisico-Quimica, Langmuir Lab de Adsorcao e Catalise (Brazil); Castro, Antonio J. R.; Filho, Josue M. [Universidade Federal do Ceara, Departamento de Fisica (Brazil); Viana, Bartolomeu C. [Universidade Federal do Piaui, Departamento de Fisica (Brazil); Campos, Adriana [CETENE Av. Prof. Luiz Freire, Cidade Universitaria (Brazil); Oliveira, Alcineia C., E-mail: alcineia@ufc.br [Universidade Federal do Ceara, Departamento de Quimica Analitica e Fisico-Quimica, Langmuir Lab de Adsorcao e Catalise (Brazil)

    2012-09-15

    Ni, Co, Ce and Ru nanoparticles were inserted into templated carbon using a nanocasting technique and evaluated for the dehydration of glycerol. NiO and CeO{sub 2} preferentially yielded 5 nm uniformly sized particles that filled the mesoporous carbon via a geometric confinement effect. Ru generated Ru{sup o} and RuO{sub 2} nanoparticles that selectively migrated towards the carbon surface and did not undergo sintering, whereas Co nanoparticles containing CoO and Co{sub 3}O{sub 4} showed the opposite behaviour. The stabilising effects of the Ce and Ru nanoparticles on the carbon matrix effectively prevented the aggregation of small particles, resulting in superior catalytic performance in glycerol dehydration.

  19. Halide-promoted reactions of alkynes with Ru sub 3 (CO) sub 12

    Energy Technology Data Exchange (ETDEWEB)

    Rivomanana, S.; Lavigne, G.; Lugan, N.; Bonnet, J.; Yanez, R.; Mathieu, R. (Universite Paul Sabatier, Toulouse (France))

    1989-11-22

    The promoter effect of anionic nucleophiles on reactions of metal carbonyl complexes is of high current interest. In particular, several novel catalytic processes of potential industrial relevance are based on Ru{sub 3}(CO){sub 12}/halide systems as catalyst precursors. The authors have found that the activated complex (PPN)(Ru{sub 3}({mu}-Cl)(CO){sub 10}) ((PPN)(3)), which is readily obtained from the initial halide adduct (PPN)(Ru{sub 3}({eta}{sup 1}-Cl)(CO){sub 11}) ((PPN)(2)) (PPN = bis(triphenylphosphine)iminium), reacts with alkynes at 25{degree}C in THF (reaction 1) to produce a labile species (PPN)(Ru{sub 3}({mu}-Cl)({mu}-{eta}{sup 2}-RCCR{prime})(CO){sub 9}) ((PPN)(4)) that serves as a convenient precursor to new and known alkyne-substituted derivatives of Ru{sub 3}(CO){sub 12}.

  20. A density functional theory study of propylene epoxidation on RuO2(110) surface

    Science.gov (United States)

    Atmaca, Deniz Onay; Düzenli, Derya; Ozbek, M. Olus; Onal, Isik

    2016-11-01

    Propylene epoxidation is investigated on RuO2(110) and oxygen added RuO2-Oot(110) surfaces by periodic DFT computational method. The desired product propylene oxide (PO) as well as the undesired products acetone (AC) or propionaldehyde (PA) form on both surfaces through either surface intermediate oxometallopropylene (OMMP) or direct oxygen insertion mechanisms. On RuO2(110) surface, nucleophilic lattice oxygen at bridge position (Obr) favors the stable surface intermediate mechanism where high energy requirements for forward reactions are demonstrated in our calculations. On RuO2-Oot(110) surface, however, higher reactivity of the electrophilic oxygen (Oot) species lowers the reaction barriers and enables an exothermic reaction path to the direct oxygen insertion for PO production. Therefore, RuO2-Oot surface is expected to show a higher PO rate.