Bifunctional catalytic activity of anion-doped LaSrCoO4 for oxygen reduction and evolution reactions.

Here, we synthesized Co-based, anion-incorporated‍ ‌R‌u‌d‌d‌l‌e‌s-d‌e‌n‌-‌Popper perovskite electrocatalysts (LaSrCoO_4-x X _y ) and compared their catalytic performances in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The ORR mechanism with the newly synthesized F-doped LaSrCoO₄ catalyst was dominated by a four-electron process, and the number of electrons involved in the reaction increased compared with that for LaSrCoO₄. The OER activity of the hydride-doped LaSrCoO₄ catalyst was the highest among the LaSrCoO₄ system catalysts. Density functional theory calculations revealed that there is a correlation between the Co 3d unoccupied orbital band centre and the OER activity. The addition of anions and substitution of metal sites improved the ORR and OER activities of the catalysts. Our findings confirmed that the addition of heteroatom anions can improve the activity of perovskite-type electrocatalysts, promoting their application in various fields.