Robust 4f-2p-3d electron ladder for boosting the stability of oxygen electrocatalysis

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are recognized as the core bifunctional catalytic processes in metal-air batteries, yet their inferior stability severely limits the large-scale deployment of these frontier devices. For resolving it, a bifunctional transition metal (TM)-based catalyst (FeCoNiSm) is successfully designed with unique Sm-O-TM structural units. The constructed (Sm)4 f -(O)2 p -(TM)3 d electronic framework builds a continuous 4 f -2 p -3 d electronic ladder that accelerates the *OOH protonation process and electron transfer, making the reaction thermodynamically more favorable. The assembled zinc-air battery exhibits exceptional long-term durability over 2064 h, with a negligible decay rate of 2.75 mV/day. Our work offers novel insights into regulating the 4 f -2 p -3 d electronic ladder via structure unit construction to boost the operational stability of bifunctional oxygen electrocatalysts.