Preparation of Pt/Irx(IrO2)10 − x bifunctional oxygen catalyst for unitized regenerative fuel cell

► Pt/Irx(IrO2)10 − x is prepared by depositing Pt on Irx(IrO2)10 − x support. ► Irx(IrO2)10 − x improves the conductivity and catalytic activity. ► Pt/Ir3(IrO2)7 exhibits high ORR activity and high OER activity. ► ORR kinetics on Pt/Ir3(IrO2)7 catalyst follows four-electron mechanism.