Fe₃C Nanoclusters Regulated Charge Asymmetric Fe Dual Atomic Sites for Enhanced Oxygen Reduction Performance

Comprehensive Summary Dual‐atom catalysts (DACs) show attractive prospects for the oxygen reduction reaction (ORR), yet face challenges in precise charge modulation that balances the activity and durability. Herein, we present a N,S‐coordinated Fe dual atomic catalyst modified by Fe 3 C nanoclusters (Fe 3 C/Fe 2 N x S) through pyrolyzing the mixtures of ZIF‐8‐encapsulated iron dimers and sulfur‐doped C 3 N 4 . Aberration‐corrected STEM and synchrotron X‐ray absorption spectroscopy (XAS) validated that the catalyst was composed of Fe dual atomic sites and Fe 3 C nanoclusters, in which Fe dual atoms were coordinated by five N atoms and one S atom. Fe 3 C/Fe 2 N x S exhibited excellent ORR activity in alkaline media, displaying a high half‐wave potential ( E 1/2 = 0.894 V vs . RHE) with near 4e – selectivity ( n = 3.92) and maintaining 86.8% retention after 20000 s, superior to commercial Pt/C. Impressively, the assembled zinc‐air battery delivered exceptional peak power density (163 mW·cm –2 ) and 200‐hour robust stability. Density functional theory (DFT) calculations revealed that electron transfer from Fe of Fe 2 N x S to neighboring Fe 3 C induced local charge asymmetry, shifting the d‐band center closer to Fermi level, thereby enhancing O 2 activation. Moreover, the OOH * formation energy barrier was reduced to 0.52 eV in Fe 3 C/Fe 2 N x S, accelerating ORR reaction kinetics. This work establishes nanocluster‐mediated electronic redistribution to tailor charge asymmetry for high‐performance electrocatalysts.