Understanding the dynamic transformation process of the oxygen evolution reaction (OER) catalysts is of importance for their rational design. Here we first report that Fe-leaching could induce the electrochemical activation of strongly coupled Ni-Fe alloy on N-doped carbon composites to boost the OER performance. It is demonstrated that the leaching of unstable FeOOH mixed layer from the surface of FeNi₃ alloy is responsible for the surface reconstruction and exposure of more active sites. Furthermore, the N-doped carbon, FeNi₃ alloy, together with the accompanying generation of Fe-doped Ni(OH)₂, synergistically promote the OER activity after fully activation. It is also verified that the high valent Ni species, pyridinnic N and the metal-N species are the exact active centers and the fully activated catalyst Fe_0.2Ni_0.8/NC-600-a is among the best non-noble OER catalysts to date, which exhibits superior OER performance with a low overpotential (η₂₀=290 mV) and small Tafel slope (76 mV dec^-1). This study is helpful to understand the fundamentals of the Ni-Fe alloy catalysts and provides guidance to design advanced catalysts for water oxidation through in-situ electrochemical activation.

了解氧释放反应（OER）催化剂的动态转化过程对其合理设计至关重要。在这里，我们首先报道，Fe浸出可以诱导N掺杂碳复合材料上强耦合Ni-Fe合金的电化学活化，从而提高OER性能。结果表明，从FeNi ₃合金表面浸出不稳定的FeOOH混合层是表面重构和更多活性位点暴露的原因。此外，N掺杂的碳FeNi ₃合金，以及随之产生的Fe掺杂的Ni（OH）₂完全激活后，协同促进OER活性。还证实了高价的Ni物种，吡啶金属N和金属N物种是精确的活性中心，完全活化的催化剂Fe _0.2 Ni _0.8 / NC-600-a是迄今为止最好的非贵金属OER催化剂之一，其表现出具有低的超电势（η优越OER性能₂₀ = 290毫伏）和小塔菲尔斜率（76毫伏癸^-1）。这项研究有助于理解镍铁合​​金催化剂的基本原理，并为设计用于通过原位电化学活化进行水氧化的高级催化剂提供指导。