Engineering First Coordination Shell of Dual‐Atom Sites via Nitrogen Vacancy for Enhanced Bifunctional Oxygen Electrocatalysis

ABSTRACT Developing dual–atom catalysts (DACs) that are simultaneously active and durable for reversible oxygen reduction/evolution (ORR/OER) remains challenging yet essential for rechargeable zinc–air batteries (ZABs). Herein, we design a heterogeneous electrocatalyst comprising atomically dispersed NiN 3 and FeN 3 dual sites, together with NiFeRu x nanoclusters, anchored on carbon nanotubes‐intertwined carbon nanocage (NiFeRu x @NiN 3– FeN 3 ). The NiFeRu x nanoclusters induce nitrogen‐vacancy formation adjacent to the NiN 3 and FeN 3 dual sites and catalyze the generation of a highly graphitic carbon matrix. These structural features endow NiFeRu x @NiN 3 –FeN 3 an ORR half‐wave potential of 0.894 V and an OER potential of 1.533 V at 10 mA cm −2 in 0.1 m KOH electrolyte, outperforming the counterparts featuring NiN 4 –FeN 4 dual sites as well as benchmark Pt/C and RuO 2 catalysts. Theoretical calculations reveal that nitrogen vacancy‐ and NiFeRu x clusters‐induced structural distortion redistributes electron density at the Ni/Fe centers, optimizing * OH adsorption and lowering the energy barriers of the potential‐determining steps. When employed NiFeRu x @NiN 3 –FeN 3 as the cathode catalyst, the resulting ZABs deliver a high peak power density of 239.4 mW cm −2 and an exceptional cycling stability over 1500 h (2250 cycles), highlighting its promise for practical energy storage.