A-Site Management Prompts the Dynamic Reconstructed Active Phase of Perovskite Oxide OER Catalysts

Perovskites (ABX 3 ) are promising oxygen evolution reaction (OER) catalysts for their highly intrinsic activity. The in-depth understanding and the adjustment of dynamic reconstruction of active phases for perovskites in OER are still a daunting challenge. Here, a refined A-site management strategy is proposed for perovskite oxides, which facilitates the surface reconstruction of the B-site element based active phase to enhance the OER performance. Electrocatalyst LaNiO 3 displays a dynamic reconstruction feature during OER with the growth of a self-assembled NiOOH active layer, based on the in situ electrochemical Raman technology. Precise A-site Ce doping lowers the reconstruction potential for the active phase and the dynamic structure–activity correlation is well established. Theoretical calculations demonstrate that A-site Ce substitution upshifts the O 2p level for greater structural flexibility with optimized oxygen vacancy content, thereby activating the B-site atom and promoting the active phase reconstruction. These results suggest that A-site management prompts the B-site element based active phase dynamic reconstruction via engineered X-site content as a bridge. Therefore, indicating the strong correlation of each-site component in perovskite oxides during OER and deepening the understanding of the fundamental processes of the structural transformation and further benefiting the accurate design of high-efficiency perovskite OER electrocatalysts.