Fast and Durable Alkaline Hydrogen Oxidation Reaction at the Electron-Deficient Ruthenium-Ruthenium Oxide Interface

The slow hydrogen oxidation reaction (HOR) kinetics under alkaline conditions remain a critical challenge for the practical application of alkaline exchange membrane fuel cells. Herein, Ru/RuO2 in-plane heterostructures are designed with abundant active Ru-RuO2 interface domains as efficient electrocatalysts for the HOR in alkaline media. The experimental and theoretical results demonstrate that interfacial Ru and RuO2 domains at Ru-RuO2 interfaces are the optimal H and OH adsorption sites, respectively, endowing the well-defined Ru(100)/RuO2(200) interface as the preferential region for fast alkaline hydrogen electrocatalysis. More importantly, the metallic Ru domains become electron deficient due to the strong interaction with RuO2 domains and show substantially improved inoxidizability, which is vital to maintain durable HOR electrocatalytic activity. The optimal Ru/RuO2 heterostructured electrocatalyst exhibits impressive alkaline HOR activity with an exchange current density of 8.86 mA cm(-2) and decent durability. The exceptional electrocatalytic performance of Ru/RuO2 in-plane heterostructure can be attributed to the robust and multifunctional Ru-RuO2 interfaces endowed by the unique metal-metal oxide domains.

Automated summary

In this study, Ru/RuO2 in-plane heterostructures with abundant active Ru-RuO2 interface domains were designed as efficient electrocatalysts for the hydrogen oxidation reaction (HOR) in alkaline media. These heterostructures exhibited impressive alkaline HOR activity due to the optimal adsorption sites for H and OH at the Ru-RuO2 interfaces. The robust and multifunctional Ru-RuO2 interfaces endowed by the unique metal-metal oxide domains contributed to the exceptional electrocatalytic performance.