Strategic Design\nfor High-Efficiency Oxygen Evolution\nReaction (OER) Catalysts by Triggering Lattice Oxygen Oxidation\nin Cobalt Spinel Oxides

High-efficiency catalysts with refined electronic structures\nare\nhighly desirable for promoting the kinetics of the oxygen evolution\nreaction (OER) and enhancing catalyst durability. This study comprehensively\nexplores strategies involving metal doping and oxygen vacancies for\nenhancing the acidic OER catalytic activity of Co<sub>3</sub>O<sub>4</sub>. Through extensive screening of 3d and 4d transition metals\nusing density functional theory (DFT) simulations, we demonstrate\nthat the incorporation of metal dopants and oxygen vacancies into\nCo<sub>3</sub>O<sub>4</sub> potentially triggers a transition from\nthe adsorbate evolution mechanism (AEM) to the lattice oxygen oxidation\nmechanism (LOM) in the oxygen evolution reaction (OER). While the\nformation of the O–O bond in the intermediate *OOH poses challenges,\na significantly reduced overpotential facilitates efficient conversion\nof O to O<sub>2</sub> through the LOM in *OH and lattice oxygen. Additionally,\nwe find that Mn doping can significantly improve the stability of\nthe catalyst. Building upon the rationale above, we employed a dual\ndoping strategy in subsequent experiments to enhance both the activity\nand stability. Our final design involved the codoping of Mn and Ru\nin Co<sub>3</sub>O<sub>4</sub>, along with an appropriate amount of\noxygen vacancies. This catalyst demonstrates a low overpotential (η<sub>10</sub> = 230 mV) compared to pure Co<sub>3</sub>O<sub>4</sub> and\nmaintains stable operation for over 120 h, representing a 12-fold\nincrease. By exploring and harnessing the LOM, more efficient, stable,\nand cost-effective OER catalysts can be designed, providing crucial\nsupport for technologies such as water electrolysis in clean energy.