Surface reconstruction is widely existed on the surface of transition metal-based catalysts under operando oxygen evolution reaction (OER) condition. The design and optimize the reconstruction process are essential to achieve high electrochemical active surface and thus facilitate the reaction kinetics, whereas still challenge. Herein, we exploit electrolyte engineering to regulate reconstruction on the surface of Fe₂O₃ catalysts under operando OER conditions. The intentional added cations in electrolyte can participate the reconstruction process and realize a desirable crystalline to amorphous structure conversion, contributing abundant well-defined active sites. Spectroscopic measurements and density functional theory calculation provide insight into the underlying role of amorphous structure for electron transfer, mass transport, and intermediate adsorption. With the assistant of Co²⁺ cations, the enhanced current density as large as 17.9 % can be achieved at 2.32 V (vs RHE). The present results indicate the potential of electrolyte engineering for regulating the reconstruction process and provide a generalized in-situ strategy for advanced catalysts design.

在原位析氧反应（OER）条件下，过渡金属基催化剂的表面广泛存在表面重构。设计和优化重构过程对于实现高电化学活性表面至关重要，从而促进反应动力学，但仍然具有挑战性。在此，我们利用电解质工程来调节 Fe ₂ O ₃催化剂在操作 OER 条件下表面的重构。电解质中有意添加的阳离子可以参与重构过程并实现理想的结晶到非晶结构的转换，从而提供丰富的明确的活性位点。光谱测量和密度泛函理论计算可以深入了解非晶结构对于电子转移、质量传递和中间吸附的潜在作用。在Co ²⁺阳离子的帮助下，在2.32 V（vs RHE）下电流密度可提高17.9%。目前的结果表明电解质工程在调节重构过程方面的潜力，并为先进催化剂设计提供了通用的原位策略。