Carbon-Vacancy-Induced Fe Coordination Modulation in FeZn Dual-Atom Sites for Enhanced Bifunctional Oxygen Electrocatalysis

Precisely modulating the coordination structure of neighboring metal atomic sites is urgently required yet remains technically challenging. Herein, we report a carbon-vacancy-induced Fe coordination environment modulation in FeZn dual-atom sites (FeZnN 6 -V C ) to boost bifunctional oxygen electrocatalysis. Finite element simulation and electronic structure characterization reveal that carbon vacancies promote electron transfer from Fe–N 4 to neighboring Zn–N 4 sites, establishing favorable electronic interactions. In situ Raman spectroscopy further identifies the key O–O – intermediate (corresponding to OOH*) and the FeOOH active phase during oxygen evolution reaction (OER), both showing significantly lowered onset potentials. Compared with conventional FeZn dual-atom catalysts, FeZnN 6 -V C achieves a 174 mV decrease in OER overpotential at 10 mA cm –2 and exhibits improved oxygen reduction reaction performance in alkaline media. The corresponding quasi-solid-state Zn–air battery delivers a long cycling life of 82.3 h at 50 mA cm –2 . This work offers a versatile carbon-vacancy strategy to tune the local coordination of dual-atomic sites for advanced electrocatalysis.