MOF‐Superstructure‐Derived 2D Fe 2 O 3 /Fe‐N‐C Nanosheets as Catalysts for Zn‐Air Batteries: Synergistically Enhanced Mass Transport and Electrocatalytic Activity

Metal‐organic framework (MOF)‐derived single‐atom Fe‐N‐C catalysts exhibit promising oxygen reduction reaction (ORR) activity. However, their practical performance in zinc‐air batteries (ZABs) is hindered by low active site utilization efficiency and excessively strong adsorption of ORR intermediates. Herein, we fabricate a catalyst featuring atomically dispersed Fe and Fe 2 O 3 nanoparticles anchored on large‐scale two‐dimensional (2D) carbon nanosheets via pyrolysis of MOF superstructure precursors. A dual Fe‐source strategy enhances Fe/N contents while creating abundant Fe‐N x and N‐doped carbon active sites. Experimental and theoretical results reveal that the 2D nanosheet architecture provides high O 2 storage capacity and rapid mass transfer channels, significantly improving Fe‐N x site utilization. Meanwhile, Fe 2 O 3 modulates Fe's d‐p orbital hybridization and enhances outermost electron delocalization, weakening excessive binding of ORR intermediates. Consequently, the Fe 2 O 3 /Fe‐N‐C nanosheet catalyst demonstrates superior ORR performance and enhanced ZABs performance compared to conventional Fe‐N‐C nanoparticle catalysts. This study offers new insights into developing high‐performance ORR catalysts through synergistic optimization of single‐atom active site electronic structures and support architecture.