Metal-Oxide-Supported Ir-decorated Electrocatalysts for Polymer Electrolyte Membrane Water Electrolysis

摘要

Carbon black is difficult to be used as the catalyst support material for polymer electrolyte membrane water electrolysis (PEMWE) due to carbon corrosion at a high potential. In order to prepare iridium-based nano-size electrocatalysts similar to PEFC, SnO_2 and TiO_2 are considered as possible catalyst support materials with high potential stability. In this study, we prepare (i) iridium-decorated SnO_2 supported on Vapor-Grown Cabon Fiber (IrO_2/Sn(Nb)O_2/VGCF) and (ii) carbon-free Ir/TiOx/Ti sheet where Ti sheet naturally with oxide surface is used as the catalyst support and the gas diffusion layer (GDL). Ir nanoparticles on each metal oxide support could be prepared, confirmed by electron microscopy. The Ir/TiOx/Ti electrode exhibited higher I-V characteristics with a lower Ir loading than the IrO_2/Sn(Nb)O_2/VGCF electrode.