Understanding the Effect of the Valence State of Perovskite B‐Site Ions on Its Oxygen Electrocatalytic Performance

Abstract The relationship between the interactions of valence, electronic structure and orbitals generated by rare‐earth doped perovskites and the electrocatalytic mechanism is important research work. Herein, the experimental and theoretical studies prepared through La 1– x Sm x MnO 3 show that the doping of Sm triggers the B‐site active center, which will promote the ORR and OER kinetics at the catalyst interface, and ultimately give La 0.7 Sm 0.3 MnO 3 (LSM0.3) which has the most positive half‐wave potential of 0.70 V versus RHE and the smallest overpotential of 0.48 V. Meanwhile, the specific electron configuration of Sm reduces the grain boundary energy and suppresses Oswald maturation, which causes the smallest reduction for ORR current density during long‐term operation. Finally, zinc‐air cell assembled with LSM0.3 as a cathode catalyst can be cycled stably for 330 h at 1 mA cm −2 . This work provides new insight into the improved electrocatalytic performance of oxygen by rare‐earth doped perovskites.