Transition‐metal‐based compounds have been intensively explored as efficient electrocatalysts for hydrogen evolution reaction (HER). Feasible reconstruction to the real active sites, which is yet to be identified, endows the promotion of HER activity. Here, it is reported that the incoming S coordinates and anion vacancies prompt the structural reconstruction of S‐doped Co3O4 on carbon cloth (S‐Co3O4/CC) during HER. A list of in situ studies reveals that the real active sites for HER are the “metallic surface‐adparticles” system embracing metallic Co scaffold and the dilute coverage of S coordinated Coδ+. Reaction mechanism exploration illustrates that interfacial perimeters between the coverage of Co3S4 moieties and metallic Co considerably facilitate the adsorption of H*, improve the kinetics of water dissociation, and consequently promote HER activity. The exemplified sulfide‐mediated topotactic transformation strategy is extended to the preparation of S, Fe codoped Ni(OH)2 (S‐NiFe/CC) as a bifunctional electrocatalyst. The assembled anion exchange membrane water electrolyzer achieves a current density of 1.0 A cm−2 at 1.72 V, showing excellent capability in catalyzing overall water splitting at ampere level. This study, showing a feasible strategy that enables the facile reconstruction to identify active sites, would inspire the development of efficient electrocatalysts for HER and other electrochemical hydrogenation reaction.

中文翻译：

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原位重建表面硫化物吸附金属支架以增强电催化析氢活性

过渡金属基化合物作为析氢反应（HER）的有效电催化剂已被广泛探索。对尚未确定的真正活性位点进行可行的重建可以促进 HER 活性。据报道，传入的 S 坐标和阴离子空位促进了 S 掺杂 Co 的结构重建3氧4碳布上（S-Co3氧4/CC）在她期间。一系列原位研究表明，HER 的真正活性位点是包含金属 Co 支架的“金属表面颗粒”系统和 S 配位 Co 的稀释覆盖δ+。反应机理探索表明 Co 覆盖层之间的界面周长3S4部分和金属Co显着促进H*的吸附，改善水解离动力学，从而促进HER活性。将示例的硫化物介导的拓扑转化策略扩展到 S、Fe 共掺杂 Ni(OH)2 的制备2(S-NiFe/CC)作为双功能电催化剂。组装好的阴离子交换膜水电解槽电流密度达到1.0 A cm−2电压为1.72 V，在安培水平上表现出优异的整体水分解催化能力。这项研究展示了一种可行的策略，能够轻松重建以识别活性位点，将激励开发用于 HER 和其他电化学氢化反应的高效电催化剂。