Sr-Doped Double Perovskite La2CoMnO6 to Promote the Oxygen Evolution Reaction Activity

Graphical Substitute A-site : The effect of Sr-doping on the performance of double perovskite La 2 CoMnO 6 for catalyzing oxygen evolution reaction (OER) has been studied. The A-site partially substituted compounds, which were obtained via a facile sol-gel method, have proved to have better OER performances compared with La 2 CoMnO 6 . A higher content of oxygen vacancies together with the optimized e g orbit filling make contribution to the enhanced OER activity. Developing effective electrocatalysts for oxygen evolution reaction (OER) is crucial for exploring clean fuels. Owing to the flexible structure and unique 3d electron structure, perovskite has been considered as a promising candidate for OER electrocatalyst. Here, we report a range of A-site partially substituted perovskite obtained via a facile sol-gel method, La 2- x Sr x CoMnO 6 ( x =0.2, 0.4, 0.6, 0.8, and 1.0, LSCMO- x ). LSCMO- x has been proved to have better OER performances. Therein, LSCMO-0.8 shows the best OER catalytic performance among these A-site partially substituted perovskites. The OER overpotential of LSCMO-0.8 catalyst is 0.39 V, which is reduced by 80 mV compared to parent perovskite La 2 CoMnO 6 (LCMO, 0.47 V). The experimental studies have shown that LSCMO-0.8 exhibits a higher content of oxygen vacancies compared with LCMO, which may be the factor for the enhanced OER activity. Meanwhile, it is revealed that Sr doped in the A site can efficiently optimize the e g orbit filling. This work manifests that doping Sr into perovskites appropriately is an effective strategy for the improvement of OER activity.