Hierarchically micro- and meso-porous Fe-N4O-doped carbon as robust electrocatalyst for CO2 reduction

Electrochemical reduction of carbon dioxide (CO2) is a potentially useful step in energy storage and greenhouse gas alleviation. Here we demonstrate for the first time a Fe-N4O-doped nanoporous carbon as robust electrocatalyst for CO2 reduction, where the five-coordinated Fe-N4O structure works as catalytically active site. It exhibits a high faradaic efficiency of 96 % towards CO with partial current density of -5.4 mA cm−2 at low overpotential of 470 mV. First-principles density functional theory calculations reveal that the free energy barrier for *CO desorption is greatly reduced on Fe-N4O site compared to Fe-N4, resulting in a higher selectivity to CO for a wider electrochemical window. This work opens up new possibilities for improving the catalytic performance of metal-N-C electrocatalysts by regulating the co-ordination of metal atom.