Regulating the d-band center of Ru/CoMoO4 ternary heterostructure by interface engineering for accelerated hydrogen adsorption kinetics

Developing low-cost, high-performance Ru-based hydrogen evolution reaction (HER) catalysts is crucial for advancing anion exchange membrane water electrolysis (AEMWE) technology. In this study, based on the Sabatier principle, a Ru/CoMoO 4 heterojunction catalyst with a ternary “nanorod-macroparticle-microparticle” structure is designed. Benefiting from the strong electronic interactions, a lower d-band center of Ru/CoMoO 4 is observed, resulting in optimal adsorption between Ru species and the key H* intermediates to greatly enhance the hydrogen desorption kinetics. Importantly, this interface engineering effect prevents the Volmer-Tafel step from becoming rate-limiting step, thereby promoting electron and mass transport. As a consequence, Ru/CoMoO 4 outperforms most of the reported HER catalysts at an ultra-low Ru loading of only 0.2 wt%. In alkaline media, it only requires an overpotential of 55 mV to achieve 100 mA cm −2 , with a low Tafel slope of 16 mV dec -1 , and operates stably for over 230 h at an industrial-grade current density of 1000 mA cm -2 . The AEMWE electrolyzer based on the Ru/CoMoO 4 catalyst achieves efficient and stable hydrogen production at 1000 mA cm⁻ 2 @ 1.93 V. This work not only provides a high-performance catalyst, but also elucidates a strategy for precisely controlling d-band center through heterojunction interface engineering to optimize reaction [email protected]