Boosting Oxygen Reduction Catalysis on Fe─N─C via Long‐Range Electronic Metal–Support Interaction from Ultrasmall Fe/Fe ₂ O ₃

ABSTRACT Single‐atom Fe─N─C catalysts are promising alternatives to Pt‐based catalysts for the oxygen reduction reaction (ORR), yet their performance is often limited by insufficient electronic modulation of the isolated Fe─N ₄ sites. Herein, we develop a facile chemical vapor deposition approach to synthesize a Fe─N─C catalyst (denoted as FF/Fe─NC) that simultaneously incorporates surface‐accessible Fe/Fe ₂ O ₃ nanoparticles (∼1.0 nm) and atomically dispersed Fe─N ₄ sites. In alkaline media, FF/Fe─NC delivers a superior 4‐electron ORR activity with a half‐wave potential of 0.92 V (vs. RHE) and a high turnover frequency (1.8 s ⁻¹ at 0.9 V), significantly outperforming Fe/Fe ₂ O ₃ ‐free sample (Fe─NC) and commercial Pt/C. When employed as a cathode in a zinc‐air battery, FF/Fe─NC delivers a high peak power density (218 mW cm ⁻² ) and outstanding cycling stability. The enhanced performance is primarily attributed to the long‐range electronic metal‐support interaction (LR‐EMSI) between Fe/Fe ₂ O ₃ nanoparticles and Fe─N ₄ sites, which effectively optimizes the adsorption of reaction intermediates and accelerates the overall ORR kinetics. This work provides an effective design strategy for boosting the performance of metal and nitrogen co‐doped carbon catalysts through the rational integration of metal nanoparticles and single‐atom sites.