Reliable Synthesis of Hundred‐Gram‐Scale Fe–N–C Synergistic Catalysts With Fe–N 4 and Fe Atomic Clusters/Nanoparticles for High‐Performance Zn‐Air Batteries

Single‐atom sites integrated with atomic clusters (ACs)/nanoparticles (NPs) in M–N–C materials have emerged as advanced synergistic catalysts for oxygen reduction reaction (ORR). However, achieving their reliable and scalable synthesis, as well as elucidating the genuine contributor to the synergy, remains a significant challenge. Herein, through a facile Fe 3+ impregnation of a pristine Fe–N–C support followed by thermal activation, we achieved a hundred‐gram‐scale synthesis of a high‐quality Fe–N–C synergistic catalyst comprising Fe–N 4 and Fe ACs/NPs. By comprehensive structural characterizations and theoretical calculations, we demonstrate that the enhanced apparent ORR activity originates from the electronic modulation of Fe–N 4 sites by their adjacent acid‐resistant Fe ACs. The optimized catalyst achieves a record‐high half‐wave potential of 0.950 V and a kinetic mass‐specific activity of 69.8 A g −1 at 0.90 V in alkaline medium among the reported Fe–N–C catalysts. This catalyst as ZAB cathode delivers an outstanding peak power density of 201 mW cm −2 with superior long‐term stability, far surpassing the benchmark Pt/C. This study represents a significant milestone in advancing the practical deployment of Fe–N–C synergistic catalysts for ZABs and analogous energy conversion technologies.