Bismuth‐Mediated Zinc Extraction‐Induced Carbon Defects Boost Fe Single‐Atom Catalysis for Efficient Oxygen Reduction

ABSTRACT Fe single‐atom catalysts with Fe‐N 4 configurations typically suffer from excessive adsorption of oxygenated intermediates, leading to intrinsic limitations in catalytic efficiency. Here, we propose a Bi‐mediated Fe‐adjacent Zn extraction strategy to create defects adjacent to Fe‐N 4 moieties on ZIF‐8‐derived carbon support, thereby tailoring the local microenvironment of Fe single atoms. The resulting Fe‐N‐pC d catalyst exhibits outstanding oxygen reduction reaction (ORR) activity in alkaline electrolyte, delivering a half‐wave potential of 0.918 V versus RHE along with excellent durability. The assembled quasi‐solid‐state Zn‐air battery using Fe‐N‐pC d as the air cathode catalyst affords stable operation for over 3000 h at −40°C. Mechanistic investigations demonstrate that the formed carbon defects adjacent to Fe‐N 4 sites redistribute the local electron density and favor the formation of an axial *OH‐bound Fe state under ORR conditions. This defect‐modulated coordination environment lowers the Fe d‐band center and alleviates the overly strong Fe‐*OH coupling, thereby changing the potential‐limiting step from *OH removal to *OOH formation and accelerating ORR kinetics. This study provides a neighboring‐template extraction route for engineering defect microenvironments adjacent to metal single atoms, opening new opportunities for the design of efficient ORR electrocatalysts.