In Situ Self-Reconstructed Nanoheterostructure Catalysts for Promoting Oxygen Reduction Reaction

Constructing heterostructures to obtain catalysts with high electrocatalytic activity is an essential but challenging research direction. Herein, a new composite catalyst, modified with nanospinel on the perovskite skeleton, Pr_0.4Sr_0.6Co_0.2Fe_0.8O₃-_δ-(Co_xFe_1-x)₃O₄(sp-PSFC), is obtained using intelligent in situ compounding. Irreversibly exsolved nanoparticles are uniformly embedded on the surface of Pr_0.4Sr_0.6Co_0.2Fe_0.8O₃(PSFC) in the form of a nonshell layer to produce a nanoscale heterojunction. The structure of PSFC is fine-tuned through the exsolution of nanoparticles, resulting in B-site ion vacancies and oxygen vacancies, which promote the adsorption and migration of oxygen species. The construction of a heterointerface effectively reduces the oxygen adsorption energy of the cathode, leading to the formation of multiple reaction paths for the migration of oxygen species. This method of constructing a heterointerface by in situ irreversible exsolution overcomes the deficiency of single-phase reaction kinetics and provides a strategy for optimizing catalyst activity.