Premium
Reversible Electrocatalytic Activity of Carbon‐Supported Pt x Ni 1− x in Hydrogen Reactions
Author(s) -
Dessources Samuel,
Morais Claudia,
Napporn Têko W.,
Kokoh K. Boniface
Publication year - 2016
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201600733
Subject(s) - tafel equation , overpotential , catalysis , exchange current density , chemistry , electrocatalyst , inorganic chemistry , anode , hydrogen , bromide , electrochemistry , chemical engineering , electrode , organic chemistry , engineering
Hydrogen oxidation and evolution reactions (HOR and HER) are studied on Pt x Ni 1− 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 H 2 /O 2 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 ( j 0 ) 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 j 0 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.