Breaking the ORR Trade‐Off via Mg‐Steered Fe‐N 4 Pyridinic Conversion

ABSTRACT Single‐atom Fe sites coordinated by pyrrolic nitrogen (Fe‐N pyrr ‐C) are highly active for the oxygen reduction reaction (ORR) but suffer from rapid demetalization‐induced deactivation. Here, we overcome this limitation via a Mg‐assisted sacrificial templating strategy that precisely reconstructs Fe‐N 4 coordination, driving partial conversion of unstable pyrrolic‐N to robust pyridinic‐N ligands. The resulting Fe(Mg)‐N‐C(1) catalyst exhibits exceptional ORR performance (half‐wave potential E 1/2 = 0.91 V) and outstanding durability, retaining 95.2% of its initial current after 55 h, surpassing both Fe‐N‐C and Pt/C. In Zn‐air batteries, it enables stable operation for > 530 h (peak power density: 271 mW cm − 2 ). This work demonstrates that enriching pyridinic‐N‐coordinated Fe‐N 4 sites simultaneously enhances activity and suppresses demetalization, offering a general coordination‐engineering strategy to unify activity and stability in Fe‐N‐C electrocatalysts.