Reversible Electrocatalytic Activity of Carbon‐Supported PtxNi1−x in Hydrogen Reactions |
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Authors: | Dr. Samuel Dessources Dr. Claudia Morais Dr. Têko W. Napporn Prof. K. Boniface Kokoh |
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Affiliation: | IC2MP UMR 7285 CNRS Université de Poitiers, Poitiers CEDEX 09, France |
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Abstract: | Hydrogen oxidation and evolution reactions (HOR and HER) are studied on PtxNi1?x/C materials synthesized by the bromide anion exchange method. Physicochemical characterization shows that this surfactant‐free method enables the preparation of well‐dispersed and effective catalysts for the processes involved in the anode of H2/O2 fuel cells (HOR) and the cathode of water electrolyzers (HER). The Pt‐based materials are modified with different Ni contents to decrease the amount of costly precious metal in the electrode materials. These modified Pt‐based materials are found to be electroactive for both reactions without additional overpotential. Kinetic parameters such as the Tafel slope, exchange (j0) and kinetic current densities, and the rate‐determining steps of the reaction mechanisms are determined for each Pt–Ni catalyst and compared to those obtained at the Pt/C surface in alkaline medium. The high j0 values that are obtained indicate a probable contribution of the surface structure of the catalysts due to their roughness and the presence of oxygenated Ni species even at low potentials. |
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Keywords: | electrochemistry hydrogen nickel platinum supported catalysts |
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