Efficient and Stable Acidic Oxygen Evolution Based on W ₁₈ O ₄₉ Nanowires Supported IrO _X

Proton exchange membrane water electrolyzer (PEMWE) is considered to be a promising green hydrogen production technology but place high demand on the anodic oxygen-evolving electrocatalysts to withstand the strong oxidizing and acidic reaction condition. Here we report a robust W₁₈O₄₉ nanowire supported IrO_X (IrO_X-W₁₈O₄₉) catalyst for acidic oxygen evolution reaction (OER) prepared by chemical vapor deposition followed with polyol reduction. The catalyst exhibits excellent electrocatalytic OER performance with an overpotential of 223 mV for a current density of 10 mA cm^-2 and a small Tafel slope of 66.4 mV dec^-1 in acidic media, superior to most electrocatalysts. More impressively, the assembled three-electrode cell with IrO_X-W₁₈O₄₉ as the working electrode exhibits excellent electrocatalytic OER performance and can operate stably at 10 mA cm^-2 for 140 h. In-situ spectroscopy characterizations reveal that the IrO_X-W₁₈O₄₉ works in a route of lattice oxygen mechanism during OER. The favorable interaction between W₁₈O₄₉ nanowires and the IrO_X active species together with the strong Ir-O interaction stabilizes the high-valence Ir and prolongs the service life of the catalyst for OER.