Understanding and mastering the structural evolution of water oxidation electrocatalysts lays the foundation to finetune their catalytic activity. Herein, we demonstrate that surface reconstruction of spinel oxides originates from the metal-oxygen covalency polarity in the M_T–O–M_O backbone. A stronger M_O–O covalency relative to M_T–O covalency is found beneficial for a more thorough reconstruction towards oxyhydroxides. The structure-reconstruction relationship allows precise prediction of the reconstruction ability of spinel pre-catalysts, based on which the reconstruction degree towards the in situ generated oxyhydroxides can be controlled. The investigations of oxyhydroxides generated from spinel pre-catalysts with the same reconstruction ability provide guidelines to navigate the cation selection in spinel pre-catalysts design. This work reveals the fundamentals for manipulating the surface reconstruction of spinel pre-catalysts for water oxidation.

了解和掌握水氧化电催化剂的结构演变为微调其催化活性奠定了基础。_{在此，我们证明了尖晶石氧化物的表面重建源于 M T} –O–M _O主链中的金属-氧共价极性。相对于 M _T更强的 M _{O –O 共价性}-O 共价被发现有利于更彻底地重建羟基氧化物。结构-重构关系可以精确预测尖晶石预催化剂的重构能力，据此可以控制对原位生成的羟基氧化物的重构程度。对具有相同重构能力的尖晶石预催化剂产生的羟基氧化物的研究为尖晶石预催化剂设计中的阳离子选择提供了指导。这项工作揭示了操纵用于水氧化的尖晶石预催化剂表面重构的基本原理。