Oxygen vacancies;
Catalyst; Oxygen reduction reaction; Strong metal support interaction; Density functional theory calculation;
ABSTRACT
Tuning strong metal-support interaction between Pt-based alloys and metal oxides is an effective strategy for modulating the performance of oxygen reduction reaction (ORR). Herein, Pt3Ni alloy anchored on WOx with different content of oxygen vacancies is synthesized, and the effect of unsaturated WOx on ORR activity/stability is revealed. Electrochemical results indicate that ORR activity is positively correlated with oxygen vacancy concentration, while durability presents the opposite trend. Density functional theory (DFT) calculation results suggest that controlling the content of oxygen vacancies can usefully adjust the charge redistribution between Pt3Ni and WOx, which can optimize the adsorption/activation of reactants, thus obtaining good ORR activity. This study uncovers the effect of unsaturated WOx on ORR performance for Pt-based alloys and provides a promising strategy to design efficient and stable ORR catalysts.