Wang Shaoyan, Jiang Tao, Hao Yaming, Wu Jianxiang, Lei Can, Chen Zhe, Du Wei, Gong Ming
Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, P. R. China.
CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics Chinese Academy of Sciences (SICCAS), Shanghai, 200050, P. R. China.
Adv Mater. 2024 Nov;36(46):e2410422. doi: 10.1002/adma.202410422. Epub 2024 Sep 20.
The sluggish kinetics of hydrogen evolution reaction (HER) via water reduction limits the efficiency of alkaline water electrolysis. The HER kinetics is not only intimately related to the catalyst surface structure but also relevant to the cation identity of the electrolyte. The cation dependence also relies on the surface electronic structure and applied potential, but this interrelated effect and its underlying mechanism awaits elucidation. Herein, differently-charged molybdenum sulfide (MoS) cluster supports ([MoS] and [MoS]) are utilized to hybridize with the identical metallic Ru centers. The specific electrostatic interaction between MoS clusters and Ru precursors induces different Ru valences of the hybrids, with a higher valence state for Ru/MoS endowing a higher activity. The Ru/MoS and Ru/MoS exhibited drastically-different cation dependence, in which the charged support determines the local accumulation of cations and resulting water structures. The more negatively-charged MoS support induces the facile accumulation of cations, especially for less-hydrated K cations. The water activation capability by Ru valences and cation accumulation from the support effect in-together determine the cation-dependent alkaline HER activity. This work not only enriches the understanding about the cation-dependent HER mechanism but also shines a light on the rational optimization strategy of electrode/electrolyte interfaces.
通过水还原进行析氢反应（HER）的缓慢动力学限制了碱性水电解的效率。HER动力学不仅与催化剂表面结构密切相关，还与电解质的阳离子特性有关。阳离子依赖性还取决于表面电子结构和外加电势，但这种相互关联的效应及其潜在机制尚待阐明。在此，利用带不同电荷的硫化钼（MoS）簇载体（[MoS]和[MoS]）与相同的金属Ru中心进行杂化。MoS簇与Ru前驱体之间的特定静电相互作用诱导了杂化物中不同的Ru价态，Ru/MoS中较高的价态赋予了更高的活性。Ru/MoS和Ru/MoS表现出截然不同的阳离子依赖性，其中带电载体决定了阳离子的局部积累以及由此产生的水结构。带负电荷更多的MoS载体诱导阳离子的容易积累，特别是对于水化程度较低的K阳离子。Ru价态的水活化能力和载体效应导致的阳离子积累共同决定了阳离子依赖性碱性HER活性。这项工作不仅丰富了对阳离子依赖性HER机制的理解，还为电极/电解质界面的合理优化策略提供了启示。
