title: Reversible Electrocatalytic Activity of Carbon-Supported PtxNi1-xin Hydrogen Reactions.
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/O2fuel 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 j0values 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.
authors.affiliation: IC2MP UMR 7285 CNRS Université de Poitiers, 4, rue Michel Brunet B27 TSA 51106, 86073, Poitiers CEDEX 09, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Dessources
authors.affiliation: IC2MP UMR 7285 CNRS Université de Poitiers, 4, rue Michel Brunet B27 TSA 51106, 86073, Poitiers CEDEX 09, France.
authors.forename: Claudia
authors.initials: C
authors.lastname: Morais
authors.affiliation: IC2MP UMR 7285 CNRS Université de Poitiers, 4, rue Michel Brunet B27 TSA 51106, 86073, Poitiers CEDEX 09, France.
authors.forename: Têko W
authors.initials: TW
authors.lastname: Napporn
authors.affiliation: IC2MP UMR 7285 CNRS Université de Poitiers, 4, rue Michel Brunet B27 TSA 51106, 86073, Poitiers CEDEX 09, France.
authors.forename: K Boniface
authors.initials: KB
authors.lastname: Kokoh
keywords: electrochemistry; hydrogen; nickel; platinum; supported catalysts