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

The slow hydrogen oxidation reaction (HOR) kinetics under alkaline conditions remains a critical challenge for the practical application of alkaline exchange membrane fuel cells. Herein, we design Ru/RuO 2 in-plane heterostructures with abundant active Ru-RuO 2 interface domains as efficient electrocatalysts for HOR in alkaline media. The expertimental and theoritical results demonstrate that interfacial Ru and RuO 2 domains at Ru-RuO 2 interfaces are the optimal H and OH adsorption sites, respectively, endowing the well-defined Ru(100)/RuO 2 (200) interface as the preferential region for fast alkaline hydrogen electrocalysis. More importantly, the metallic Ru domains become electron deficient due to the strong interaction with RuO 2 domains and show substantially improved inoxidizability, which is vital to maintain durable HOR electrocatalytic activity. The optimal Ru/RuO 2 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/RuO 2 in-plane heterostructure can be attributed to the robust and multifunctional Ru-RuO 2 interfaces endowed by the unique metal-metal oxide domains. This article is protected by copyright. All rights reserved.