Cation-Driven Modulation of Interfacial Solvation Structures for Enhanced Alkaline Hydrogen Oxidation Kinetics

作者：Yana Men, Xiaomei Men, Peng Li, Lei Li, Xiaoyan Wang, Xiaozhi Su, Leijie Zhang, Shengli Chen, Wei Luo · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c03433 · 被引用次数：42 · 研究领域：Electrocatalysts for Energy Conversion、Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions

The role of interfacial water and hydrogen-bonding structures in an electric double layer (EDL) in alkaline hydrogen oxidation reaction (HOR) kinetics has garnered widespread attention. However, the dynamic evolution of alkali metal cations (AM + ), as key components in EDL, and their impact on interfacial solvation structure and alkaline HOR kinetics remain poorly understood. Here, based on the Ni 3 S 2 -island-encapsulated Ni (Ni 3 S 2 /Ni) catalyst, we demonstrate that the AM + arrangement in the EDL can be regulated by the potential of zero charge (PZC) of the electrode, which in turn controls the associated solvation environment (i.e., the ordering of interfacial water and hydrogen-bonding network). Ab initio molecular dynamics simulations, in situ surface-enhanced infrared absorption spectroscopy, and electrochemical experiments indicate that the introduction of Ni 3 S 2 fosters a lower PZC for Ni 3 S 2 /Ni, which thus promotes a less crowded cation arrangement and more disordered interfacial water structures, ultimately contributing to the accelerated shuttling of H + /OH – across the EDL through a more interconnected H-bonding network, thereby leading to a reduced energy barrier of proton-coupled electron transfer (PCET) and enhanced HOR kinetics under alkaline electrolytes. This molecular-level picture is further supported by the unconventional cation dependence of HOR activities on Ni 3 S 2 /Ni (i.e., KOH > NaOH > LiOH) by which we reveal a new mechanistic insight; ...