Spinel cobalt oxide (CoO), consisting of tetrahedral Co (Co) and octahedral Co (Co), is considered as promising earth-abundant electrocatalyst for chlorine evolution reaction (CER). Identifying the catalytic contribution of geometric Co site in the electrocatalytic CER plays a pivotal role to precisely modulate electronic configuration of active Co sites to boost CER. Herein, combining density functional theory calculations and experiment results assisted with operando analysis, we found that the Co site acts as the main active site for CER in spinel CoO, which shows better Cl adsorption and more moderate intermediate adsorption toward CER than Co site, and does not undergo redox transition under CER condition at applied potentials. Guided by above findings, the oxygen vacancies were further introduced into the CoO to precisely manipulate the electronic configuration of Co to boost Cl adsorption and optimize the reaction path of CER and thus to enhance the intrinsic CER activity significantly. Our work figures out the importance of geometric configuration dependent CER activity, shedding light on the rational design of advanced electrocatalysts from geometric configuration optimization at the atomic level.

中文翻译：

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揭示尖晶石 Co3O4 在电催化析氯反应中的几何位点依赖性活性

尖晶石氧化钴（CoO）由四面体Co（Co）和八面体Co（Co）组成，被认为是一种有前景的产氯反应（CER）电催化剂。确定电催化 CER 中几何 Co 位点的催化贡献对于精确调节活性 Co 位点的电子构型以提高 CER 起着关键作用。在此，结合密度泛函理论计算和实验结果并辅助操作分析，我们发现Co位点是尖晶石CoO中CER的主要活性位点，与Co位点相比，Co位点对CER表现出更好的Cl吸附和更温和的中间体吸附，并且在 CER 条件下施加电位时不发生氧化还原转变。在上述发现的指导下，进一步将氧空位引入CoO中，以精确控制Co的电子构型，以促进Cl吸附并优化CER的反应路径，从而显着增强内在的CER活性。我们的工作阐明了几何构型依赖的 CER 活性的重要性，从原子水平的几何构型优化中揭示了先进电催化剂的合理设计。