Boron Vacancy Enhanced Ru─Mo Electron Bridge as an Efficient Electrocatalyst for Anion Exchange Membrane Electrolysis.

Yu, Wenli; Yang, Pengfei; Liu, Fusheng; Li, Hongdong; Xiao, Weiping; Ma, Tianyi; Xu, Guangrui; Guo, Xuyun et al. · Adv Mater · 2026

basic_science · Level V

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Abstract

Hybrid electrocatalysts combining noble metals with tailored supports are crucial for efficient hydrogen evolution reaction (HER) across a wide pH range. Here, we report a ruthenium cluster catalyst anchored on molybdenum boride support engineered with boron vacancies (Ru/MoB-B<sub>V</sub>) for highly efficient HER. The introduced boron vacancies optimize the electronic interactions between molybdenum boride and the Ru cluster via a Ru─Mo electron bridge, leading to enhanced catalytic performance and stability. Combined electrochemical analysis and density functional theory calculations reveal that Ru/MoB-B<sub>V</sub> possesses a favorable water-dissociation energy and optimal desorption energies for hydrogen/hydroxide intermediates on Ru clusters. These merits confer exceptional HER performance, with overpotentials of 40 and 34 mV at 10 mA cm<sup>-2</sup> in alkaline freshwater and seawater, respectively; 24 mV in acidic electrolyte; and 67 mV in neutral electrolyte. Importantly, the activated Ru and Mo sites enable an anion exchange membrane electrolyzer employing Ru/MoB-B<sub>V</sub> as the cathode to exhibit remarkable stability, operating for 100 h at 500 mA cm<sup>-2</sup>. This work provides insights into the design of highly efficient and stable catalysts through the precise engineering of surface vacancies.