Ru-doped WO3 enabling efficient hydrogen oxidation reaction in alkaline media

Developing highly efficient hydrogen oxidation reaction (HOR) electrocatalysts in alkaline media is of great significance for anion exchange membrane fuel cells (AEMFCs). Herein, we report an efficient Ru-doped hexagonal tungsten trioxide (Ru-WO3) HOR electrocatalyst through a hydrothermal strategy. The prepared Ru-WO3 electrocatalyst exhibits enhanced HOR performance with a 6.1 times higher exchange current density and better durability than commercial Pt/C. Structural characterizations and theoretical calculations reveal that the uniformly distributed Ru was modulated by oxygen defects and the electron transfer from O to Ru modulated the H* adsorption of Ru sites. In addition, plenty of W sites can serve as hydroxyl adsorption sites to accelerate the HOR kinetics. This work not only provides an efficient HOR catalyst in alkaline media, but also promotes the fundamental understanding of the effect of modulation on the adsorption of H* and *OH in tungsten oxides with a relatively low oxidation state by Ru doping, broadening the range of HOR catalysts to Ru-doped metal oxides.