First insights into the borohydride oxidation reaction mechanism on gold by electrochemical impedance spectroscopy |
| |
Authors: | M Chatenet MB Molina-Concha J-P Diard |
| |
Affiliation: | Laboratoire d’Electrochimie et de Physico-chimie des Matériaux et des Interfaces, LEPMI, UMR 5631 CNRS/Grenoble-INP/UJF, 1130 rue de la piscine, BP75, 38402 Saint Martin d’Hères Cedex, France |
| |
Abstract: | Direct borohydride fuel cells (DBFC) exhibit some potential regarding the powering of small portable electronic devices, thanks to their high energy density as well as the facile and safe storage of borohydride salts. However, DBFC are hindered because (i) the borohydride oxidation reaction (BOR) is complex, (ii) its mechanism imperfectly determined yet and (iii) no practical electrocatalyst exhibits both fast BOR kinetics and high faradaic efficiency. In this context, we characterized the BOR mechanism for polycrystalline bulk gold (a classical model BOR electrocatalyst) in the rotating disk electrode (RDE) setup. Modeling cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) data, we propose a simplified reaction pathway, the theoretical behavior of which agrees with the experimental findings. This pathway includes at least a first irreversible electrochemical step (E) for BH4− oxidation, which competes with the electrochemical adsorption reaction (EAR) of OH− anions at high potentials. |
| |
Keywords: | Borohydride oxidation reaction Alkaline medium Gold Electrochemical impedance spectroscopy Reaction mechanism |
本文献已被 ScienceDirect 等数据库收录! |
|