Developing active single-atom-catalyst (SAC) for alkaline hydrogen evolution reaction (HER) is a promising solution to lower the green hydrogen cost. However, the correlations are not clear between the chemical environments around the active-sites and their desired catalytic activity. Here we study a group of SACs prepared by anchoring platinum atoms on NiFe-layered-double-hydroxide. While maintaining the homogeneity of the Pt-SACs, various axial ligands (−F, −Cl, −Br, −I, −OH) are employed via a facile irradiation-impregnation procedure, enabling us to discover definite chemical-environments/performance correlations. Owing to its high first-electron-affinity, chloride chelated Pt-SAC exhibits optimized bindings with hydrogen and hydroxide, which favor the sluggish water dissociation and further promote the alkaline HER. Specifically, it shows high mass-activity of 30.6 A mgPt⁻¹ and turnover frequency of 30.3 H₂ s⁻¹ at 100 mV overpotential, which are significantly higher than those of the state-of-the-art Pt-SACs and commercial Pt/C catalyst. Moreover, high energy efficiency of 80% is obtained for the alkaline water electrolyser assembled using the above catalyst under practical-relevant conditions.

开发用于碱性析氢反应 (HER) 的活性单原子催化剂 (SAC) 是降低绿氢成本的有前途的解决方案。然而，活性位点周围的化学环境与其所需催化活性之间的相关性尚不清楚。在这里，我们研究了一组通过将铂原子锚定在 NiFe 层状双氢氧化物上制备的 SAC。在保持 Pt-SAC 的均匀性的同时，使用各种轴向配体（-F、-Cl、-Br、-I、-OH ）一种简便的辐照浸渍程序，使我们能够发现明确的化学环境/性能相关性。由于其高第一电子亲和力，氯化物螯合的 Pt-SAC 与氢和氢氧化物表现出优化的结合，这有利于缓慢的水离解并进一步促进碱性 HER。^{具体而言，它在 100 mV 过电势下显示出 30.6 A mgPt -1}的高质量活性和 30.3 H ₂ s ^-1的转换频率，显着高于最先进的 Pt-SAC 和商用 Pt /C催化剂。此外，在实际相关条件下，使用上述催化剂组装的碱性水电解槽可获得80%的高能量效率。