Abstract
Developing an OER electrocatalyst that balances high performance with low cost is crucial for widely adopting PEM water electrolyzers. Ru-based catalysts are gaining attention for their cost-effectiveness and high activity, positioning them as promising alternatives to Ir-based catalysts. However, Ru-based catalysts can be prone to oxidation at high potentials, compromising their durability. In this study, we utilize a simple synthesis method to synthesize a SnO(2), Nb(2)O(5), and RuO(2) composite catalyst (SnO(2)/Nb(2)O(5)@RuO(2)) with multiple interfaces and abundant oxygen vacancies. The large surface area and numerous active sites of the SnO(2)/Nb(2)O(5)@RuO(2) catalyst lead to outstanding acidic oxygen evolution reaction (OER) performance, achieving current densities of 10, 50, and 200 mA cm(-2) at ultralow overpotentials of 287, 359, and 534 mV, respectively, significantly surpassing commercial IrO(2). Moreover, incorporating Nb(2)O(5) into the SnO(2)/Nb(2)O(5)@RuO(2) alters the electronic structure at the interfaces and generates a high density of oxygen vacancies, markedly enhancing durability. Consequently, the membrane electrode composed of SnO(2)/Nb(2)O(5)@RuO(2) and commercial Pt/C demonstrated stable operation in the PEM cell for 25 days at an industrial current density of 1 A cm(-2). This research presents a convenient approach for developing a highly efficient and durable Ru-based electrocatalyst, underscoring its potential for proton exchange membrane water electrolysis.