Cationic Defect Engineering in Perovskite La2CoMnO6 for Enhanced Electrocatalytic Oxygen Evolution

The urgent need to promote the development of sustainableenergyconversion requires exploration of highly efficient oxygen evolutionreaction (OER) electrocatalysts. Defect engineering is a promisingapproach to address the inherent low electrical conductivity of metaloxides and limited reaction sites, for use in clean air applicationsand as electrochemical energy-storage electrocatalysts. In this article,oxygen defects are introduced into La2CoMnO6-& delta; perovskite oxides through the A-site cation defect strategy. Bytuning the content of the A-site cation, oxygen defect concentrationand corresponding electrochemical OER performance have been greatlyimproved. As a result, the defective La1.8CoMnO6-& delta; (L1.8CMO) catalyst exhibits exceptional OER activitywith an overpotential of 350 mV at 10 mA cm(-2), approximately120 mV lower than that of the pristine perovskite. This enhancementcan be attributed to the increase in surface oxygen vacancies, optimizede(g) occupation of transition metal at the B-site, and enlargedBrunauer-Emmett-Teller surface area. The reported strategyfacilitates the development of novel defect-mediated perovskites inelectrocatalysis. Aseries of novel A-site-deficient perovskite catalystsLa(2-x )CoMnO(6-& delta;) with enhanced OER performance were obtained.