HIGHLIGHTS
● Atomically dispersed Fe on N-doped porous carbon combined with FexC catalysts were synthesized.
● Fe–C–N-800 exhibits excellent catalytic performance on oxidative dehydration of N-heterocycles.
● The relative content of FexC and FeNx is largely dependent on the pyrolysis temperature.
● DFT calculations and controlled trials reveal the synergistic effect of FexC and FeNx.