Accelerated O─O Bond Cleavage and Stabilized Fe Sites by Synergistic d─p Fe─Sn Dual-Atom Pair for Enhanced Oxygen...

Atomically dispersed FeNC materials have emerged as the promising catalysts for replacing precious Pt-based catalysts in the oxygen reduction reaction (ORR). However, their widespread application remains limited by sluggish kinetics and the long-term stability of the isolated Fe single-atom sites. Herein, we report a highly active and durable catalyst (FeSnNC) featuring d-block iron and p-block-metal tin dual-atom pair sites. In situ infrared spectroscopy and X-ray absorption spectroscopy, together with ab initio molecular dynamics and density functional theory calculations reveal that the Fe─Sn dual-atom pair sites enable the bridge absorption of O₂ and facilitate direct O─O bond cleavage. The redirection of *OH desorption to the Sn site alleviates Fe-site degradation, while Sn incorporation can also reinforce the Fe─N bond, jointly enhancing ORR activity and durability. Under alkaline conditions, the catalyst delivers a half-wave potential of 0.91 V and a kinetic current density of 69 mA cm^-2 at 0.85 V, with negligible performance loss after 10,000 cycles. When applied in a zinc-air battery, FeSnNC exhibits a peak power density of 262 mW cm^-2 and a cycling lifetime exceeding 1,100 hours at 10 mA cm^-2. This work demonstrates the great potential of d-p metal atomic pair sites in ORR catalysis and provides new insights into the rational design of atomically precise metal catalysts.