The Experts below are selected from a list of 334611 Experts worldwide ranked by ideXlab platform
Michael F Toney - One of the best experts on this subject based on the ideXlab platform.
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structure of dealloyed ptcu3 thin films and Catalytic Activity for oxygen reduction
Chemistry of Materials, 2010Co-Authors: Ruizhi Yang, Jennifer Leisch, Peter Strasser, Michael F ToneyAbstract:The detailed structure and composition (surface and bulk) as well as Catalytic Activity for oxygen reduction of electrochemically dealloyed PtCu3 thin films have been investigated. Synchrotron-based anomalous X-ray diffraction (AXRD) reveals that a Pt enriched surface region (∼1.0 nm thick) and a Cu depleted interior (atomic ratio different from that of PtCu3) are formed in the dealloyed film, and we directly observe a compressive lattice strain in the Pt surface region. The dealloyed PtCu3 thin films show a ∼2.4 fold increase in the specific oxygen reduction Activity over pure Pt thin films as measured by a rotating disk electrode (RDE). Our results show that the enhanced Catalytic Activity of the dealloyed Pt−Cu film is primarily due to the compressive strain in the surface layer (ligand effect is very weak). We compare our results on thin films to related results on nanoparticles. These studies provide a better understanding of the structure − composition and structure − Activity relationships in Pt-sk...
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structure of dealloyed ptcu3 thin films and Catalytic Activity for oxygen reduction
Chemistry of Materials, 2010Co-Authors: Ruizhi Yang, Jennifer Leisch, Peter Strasser, Michael F ToneyAbstract:The detailed structure and composition (surface and bulk) as well as Catalytic Activity for oxygen reduction of electrochemically dealloyed PtCu3 thin films have been investigated. Synchrotron-based anomalous X-ray diffraction (AXRD) reveals that a Pt enriched surface region (∼1.0 nm thick) and a Cu depleted interior (atomic ratio different from that of PtCu3) are formed in the dealloyed film, and we directly observe a compressive lattice strain in the Pt surface region. The dealloyed PtCu3 thin films show a ∼2.4 fold increase in the specific oxygen reduction Activity over pure Pt thin films as measured by a rotating disk electrode (RDE). Our results show that the enhanced Catalytic Activity of the dealloyed Pt−Cu film is primarily due to the compressive strain in the surface layer (ligand effect is very weak). We compare our results on thin films to related results on nanoparticles. These studies provide a better understanding of the structure − composition and structure − Activity relationships in Pt-sk...
Peter Strasser - One of the best experts on this subject based on the ideXlab platform.
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structure of dealloyed ptcu3 thin films and Catalytic Activity for oxygen reduction
Chemistry of Materials, 2010Co-Authors: Ruizhi Yang, Jennifer Leisch, Peter Strasser, Michael F ToneyAbstract:The detailed structure and composition (surface and bulk) as well as Catalytic Activity for oxygen reduction of electrochemically dealloyed PtCu3 thin films have been investigated. Synchrotron-based anomalous X-ray diffraction (AXRD) reveals that a Pt enriched surface region (∼1.0 nm thick) and a Cu depleted interior (atomic ratio different from that of PtCu3) are formed in the dealloyed film, and we directly observe a compressive lattice strain in the Pt surface region. The dealloyed PtCu3 thin films show a ∼2.4 fold increase in the specific oxygen reduction Activity over pure Pt thin films as measured by a rotating disk electrode (RDE). Our results show that the enhanced Catalytic Activity of the dealloyed Pt−Cu film is primarily due to the compressive strain in the surface layer (ligand effect is very weak). We compare our results on thin films to related results on nanoparticles. These studies provide a better understanding of the structure − composition and structure − Activity relationships in Pt-sk...
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structure of dealloyed ptcu3 thin films and Catalytic Activity for oxygen reduction
Chemistry of Materials, 2010Co-Authors: Ruizhi Yang, Jennifer Leisch, Peter Strasser, Michael F ToneyAbstract:The detailed structure and composition (surface and bulk) as well as Catalytic Activity for oxygen reduction of electrochemically dealloyed PtCu3 thin films have been investigated. Synchrotron-based anomalous X-ray diffraction (AXRD) reveals that a Pt enriched surface region (∼1.0 nm thick) and a Cu depleted interior (atomic ratio different from that of PtCu3) are formed in the dealloyed film, and we directly observe a compressive lattice strain in the Pt surface region. The dealloyed PtCu3 thin films show a ∼2.4 fold increase in the specific oxygen reduction Activity over pure Pt thin films as measured by a rotating disk electrode (RDE). Our results show that the enhanced Catalytic Activity of the dealloyed Pt−Cu film is primarily due to the compressive strain in the surface layer (ligand effect is very weak). We compare our results on thin films to related results on nanoparticles. These studies provide a better understanding of the structure − composition and structure − Activity relationships in Pt-sk...
Ruizhi Yang - One of the best experts on this subject based on the ideXlab platform.
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structure of dealloyed ptcu3 thin films and Catalytic Activity for oxygen reduction
Chemistry of Materials, 2010Co-Authors: Ruizhi Yang, Jennifer Leisch, Peter Strasser, Michael F ToneyAbstract:The detailed structure and composition (surface and bulk) as well as Catalytic Activity for oxygen reduction of electrochemically dealloyed PtCu3 thin films have been investigated. Synchrotron-based anomalous X-ray diffraction (AXRD) reveals that a Pt enriched surface region (∼1.0 nm thick) and a Cu depleted interior (atomic ratio different from that of PtCu3) are formed in the dealloyed film, and we directly observe a compressive lattice strain in the Pt surface region. The dealloyed PtCu3 thin films show a ∼2.4 fold increase in the specific oxygen reduction Activity over pure Pt thin films as measured by a rotating disk electrode (RDE). Our results show that the enhanced Catalytic Activity of the dealloyed Pt−Cu film is primarily due to the compressive strain in the surface layer (ligand effect is very weak). We compare our results on thin films to related results on nanoparticles. These studies provide a better understanding of the structure − composition and structure − Activity relationships in Pt-sk...
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structure of dealloyed ptcu3 thin films and Catalytic Activity for oxygen reduction
Chemistry of Materials, 2010Co-Authors: Ruizhi Yang, Jennifer Leisch, Peter Strasser, Michael F ToneyAbstract:The detailed structure and composition (surface and bulk) as well as Catalytic Activity for oxygen reduction of electrochemically dealloyed PtCu3 thin films have been investigated. Synchrotron-based anomalous X-ray diffraction (AXRD) reveals that a Pt enriched surface region (∼1.0 nm thick) and a Cu depleted interior (atomic ratio different from that of PtCu3) are formed in the dealloyed film, and we directly observe a compressive lattice strain in the Pt surface region. The dealloyed PtCu3 thin films show a ∼2.4 fold increase in the specific oxygen reduction Activity over pure Pt thin films as measured by a rotating disk electrode (RDE). Our results show that the enhanced Catalytic Activity of the dealloyed Pt−Cu film is primarily due to the compressive strain in the surface layer (ligand effect is very weak). We compare our results on thin films to related results on nanoparticles. These studies provide a better understanding of the structure − composition and structure − Activity relationships in Pt-sk...
Hideo Hosono - One of the best experts on this subject based on the ideXlab platform.
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water durable electride y5si3 electronic structure and Catalytic Activity for ammonia synthesis
Journal of the American Chemical Society, 2016Co-Authors: Yangfan Lu, Masaaki Kitano, Toshiharu Yokoyama, Jiang Li, Tomofumi Tada, Yoshitake Toda, Shigenori Ueda, Hideo HosonoAbstract:We report an air and water stable electride Y5Si3 and its Catalytic Activity for direct ammonia synthesis. It crystallizes in the Mn5Si3-type structure and confines 0.79/f.u. anionic electrons in the quasi-one-dimensional holes. These anionic electrons strongly hybridize with yttrium 4d electrons, giving rise to improved chemical stability. The ammonia synthesis rate using Ru(7.8 wt %)-loaded Y5Si3 was as high as 1.9 mmol/g/h under 0.1 MPa and at 400 °C with activation energy of ∼50 kJ/mol. Its strong electron-donating ability to Ru metal of Y5Si3 is considered to enhance nitrogen dissociation and reduce the activation energy of ammonia synthesis reaction. Catalytic Activity was not suppressed even after Y5Si3, once dipped into water, was used as the catalyst promoter. These findings provide novel insights into the design of simple catalysts for ammonia synthesis.
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water durable electride y si electronic structure and Catalytic Activity for ammonia synthesis
Journal of the American Chemical Society, 2016Co-Authors: Tomofumi Tada, Masaaki Kitano, Toshiharu Yokoyama, Yoshitake Toda, Shigenori Ueda, Hideo HosonoAbstract:We report an air and water stable electride Y5Si3 and its Catalytic Activity for direct ammonia synthesis. It crystallizes in the Mn5Si3-type structure and confines 0.79/f.u. anionic electrons in the quasi-one-dimensional holes. These anionic electrons strongly hybridize with yttrium 4d electrons, giving rise to improved chemical stability. The ammonia synthesis rate using Ru(7.8 wt %)-loaded Y5Si3 was as high as 1.9 mmol/g/h under 0.1 MPa and at 400 °C with activation energy of ∼50 kJ/mol. Its strong electron-donating ability to Ru metal of Y5Si3 is considered to enhance nitrogen dissociation and reduce the activation energy of ammonia synthesis reaction. Catalytic Activity was not suppressed even after Y5Si3, once dipped into water, was used as the catalyst promoter. These findings provide novel insights into the design of simple catalysts for ammonia synthesis.
Matteo Planchestainer - One of the best experts on this subject based on the ideXlab platform.
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carbene induced rescue of Catalytic Activity in deactivated nitrite reductase mutant
Chemistry: A European Journal, 2020Co-Authors: Matteo Planchestainer, Jonathan Mcmaster, Christine E Schulz, Francesca Paradisi, Martin AlbrechtAbstract:The role of His145 in the T1 copper center of Nitrite Reductase (NiR) is pivotal for the Activity of the enzyme. Mutation to a glycine at this position enables the reconstitution of the T1 center by the addition of imidazole as exogenous ligands, however the Catalytic Activity is only marginally rescued. Here we demonstrate that the uptake of 1,3‐dimethylimidazolylidene as N‐heterocyclic carbene (NHC) by the H145G NiR mutant instead of imidazole yields a significantly more active catalyst, suggesting a beneficial role of such C‐bonding. Spectroscopic analyses of the formed H145G~NHC variant as well as an analogue without the Catalytic T2 copper center reveals no significant alteration of the T1 site compared to the wild type or the variant containing imidazole as exogenous N‐bound surrogate of H145. However, the presence of the carbene doubles the Catalytic Activity of the mutant compared to the imidazole variant. This enhanced Activity has been attributed to a faster electron transfer to the T1 center in the NHC variant and a concomitant change of the rate‐limiting step.
