A composite-template strategy creates Fe–N–C catalysts with curved Fe–N4 sites and hierarchical porosity.
Curved surfaces stretch Fe–N bonds, promoting *OH desorption and accelerating ORR kinetics.
The catalyst achieves a high half-wave potential of 0.91 V and ~7× higher mass activity.
Calculations show a lower rate-determining barrier and weakened Fe–OH bonding.
In Zn–air batteries, it outperforms Pt/C with higher power density and capacity.
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Schematic of the synthesis and structural characterizations of f-Fe-NC and Fe-NC
Coordination environment of f-Fe-NC and Fe-NC
ORR performance in O2-saturated 0.1 M KOH solution
Theoretical calculations
Performance of zinc-air battery