Engineering Proton‐Coupled Electron Transfer to Break Activity‐Stability Trade‐off of Oxygen Electroreduction Catalysts for Temperature‐Adaptive Zn‐Air Battery

Single‐atom catalysts (SACs) are regarded as effective electrocatalysts for oxygen reduction reaction (ORR). However, integrating high active and long‐term durability on SACs is still challenging due to the severe limitations of activity‐stability trade‐off. Herein, we report an integrative electrocatalyst combining isolated Fe sites and MoC nanoparticles (MoC/Fe‐NC). MoC nanoparticles accelerate ORR kinetics via the proton‐feeding effect and optimize Fe site microstructure. Thus, MoC/Fe‐NC exhibits a high alkaline ORR activity with half‐wave potential (E1/2) of 0.916 V vs. the reversible hydrogen electrode, and exceptional durability of 50k cycles with 5 mV E1/2 loss. The observed ORR performance is further verified in a zinc‐air battery (ZAB) with a high peak power density of 316 mW cm−2 and operational stability over 1000 h. Moreover, the fabricated temperature‐adaptive quasi‐solid‐state ZAB can cycle stably for 150 h under alternating temperatures. Theory calculations and experiment characterizations, involving scanning electrochemical microscopy techniques and distribution of relaxation times analysis, reveal that the excellent capabilities of MoC/Fe‐NC arise from accelerated proton‐coupled electron transfer, weakened *OH adsorption, and strengthened Fe−N bonds fueled by MoC nanoparticles. This work sheds light on breaking the activity‐stability trade‐off barrier of SACs for energy‐conversion applications.