ZIF‐Derived FeCo Nanoparticles and FeN ₄ Single‐Atom Sites for High‐Performance Oxygen Evolution and Oxygen Reduction Bifunctional Electrocatalysis

Atomically dispersed nitrogen‐coordinated iron single atoms on carbon (FeN 4 SACs) stand out as highly promising non‐precious metal catalysts for the air cathode of zinc‐air batteries (ZABs). Herein, we improve bifunctional catalytic performance by uniformly anchoring FeCo nanoparticles onto a 3D cubic FeN 4 substrate through internal vapor‐phase etching and surface confinement engineering. In alkaline electrolyte, Fe 1 Co 1 @FeNC delivers exceptional bifunctionality with an ORR E 1/2 of 0.904 V and an OER overpotential of 308 mV at 10 mA cm −2 . The catalyst also exhibits excellent long‐term cycling stability, with only a negligible E 1/2 decay of 18 mV after 10,000 consecutive cycles. Notably, Fe 1 Co 1 @FeNC‐based ZABs deliver a peak power density of 167.67 mW cm −2 and over 600 h of cycling stability, outperforming benchmark Pt/C + RuO 2 . Density functional theory (DFT) reveals that the synergy between FeCo nanoparticles and Fe single atoms promotes interfacial electron transfer and downshifts the Fe d‐band center. This modulates the electronic configuration and weakens *OH binding, optimizing intermediate adsorption energies to significantly boost the intrinsic bifunctional activity.