Efficient and stable acidic oxygen evolution based on W18O49 nanowires supported IrOX

Proton exchange membrane water electrolyzer (PEMWE) is considered to be a promising green hydrogen production technology but places 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 IrOX (IrOX‐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 IrOX‐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 IrOX‐W18O49 works in a route of lattice oxygen mechanism during OER. The favorable interaction between W18O49 nanowires and the IrOX active species together with the strong Ir‐O interaction stabilizes the high‐valence Ir and prolongs the service life of the catalyst for OER.