Breaking the Ru−O−Ru Symmetry of a RuO2 Catalyst for Sustainable Acidic Water Oxidation

Abstract Proton exchange membrane water electrolysis is a highly promising hydrogen production technique for sustainable energy supply, however, achieving a highly active and durable catalyst for acidic water oxidation still remains a formidable challenge. Herein, we propose a local microenvironment regulation strategy for precisely tuning In−RuO2/graphene (In−RuO2/G) catalyst with intrinsic electrochemical activity and stability to boost acidic water oxidation. The In−RuO2/G displays robust acid oxygen evolution reaction performance with a mass activity of 671 A gcat−1 at 1.5 V, an overpotential of 187 mV at 10 mA cm−2, and long‐lasting stability of 350 h at 100 mA cm−2, which arises from the asymmetric Ru−O−In local structure interactions. Further, it is unraveled theoretically that the asymmetric Ru−O−In structure breaks the thermodynamic activity limit of the traditional adsorption evolution mechanism which significantly weakens the formation energy barrier of OOH*, thus inducing a new rate‐determining step of OH* absorption. Therefore, this strategy showcases the immense potential for constructing high‐performance acidic catalysts for water electrolyzers.