Pyrrolic N-doped Carbon Catalysts for Highly Efficient Electrocatalytic Reduction of CO2 with Superior CO Selectivity over a Wide Potential Window

The electrocatalytic reduction of CO2 to CO is an attractive approach for converting the greenhouse gas to valueadded chemicals. However, current catalysts still suffer from low catalytic reactivity and low CO selectivity. Here, we report the synthesis of a series of N-doped carbon catalysts by thermal annealing of the mixture of urea and carbon in argon under varied temperatures, enabling the rational modulation of N species in carbon. The as prepared NC-650 catalyst with pyrrolic N as the dominant N species can preferentially reduce CO2 to CO with almost 100% CO selectivity over a broad potential range (-0.45 to-1.05 V), coupled with remarkable long-term stability for over 300 h. DFT calculations reveal that the pyrrolic N site is unsaturated (valence state), which favors the formation of the N-COOH unit geometrically and electronically via proton-coupled electron transfer while inhibit hydrogen liberation, resulting in high CO2RR reactivity and CO selectivity of the NC-650 catalyst.