Single iron atoms coordinated to g-C3N4 on hierarchical porous N-doped carbon polyhedra as a high-performance electrocatalyst for the oxygen reduction reaction.

Catalysts composed of isolated single Fe atoms coordinated to graphitic carbon nitride (g-C3N4) dispersed on hierarchical porous N-doped carbon polyhedra (Fe-g-C3N4/HPNCPs) were successfully prepared. The optimized catalyst, Fe-g-C3N4/HPNCP-0.8, showed excellent electrocatalytic activity for the oxygen reduction reaction under alkaline conditions with a half-wave potential of 0.902 V, significantly outperforming commercial Pt/C, as well as high durability. The high performance stems from the synergistic effect of the atomically dispersed Fe-N2 sites and the advantages of the hierarchical porous structure for promoting mass transport and improving the accessibility of the active sites.