The Effect of the Coordination Environment of Atomically Dispersed Fe and N Co-doped Carbon Nanosheets on CO2 Electroreduction

Single-atom metal and nitrogen co-doped carbon catalysts have caused an extensive research boom for electrochemical CO2 reduction reaction (CO2RR). The diversity of metal-N coordination environment at high temperature limits the accurate study of electrocatalytic active sites. In this work, Fe porphyrin is anchored on a nitrogen-doped graphene substrate through the coordination between Fe and N atoms to form atomically dispersed Fe and N co-doped graphene nanosheets. The confinement anchoring effect of the nitrogen-doped graphene substrate prevents Fe atoms from agglomerating into Fe nanoparticles. Apart from that, the different Fe-N coordination environments and their catalytic effects on CO2RR are investigated by temperature changes. Electrochemical tests and density functional theory (DFT) calculations indicate that the atomically dispersed saturated Fe-N coordination catalyst have excellent performance for CO2RR and the Faradaic efficiency towards CO can up to 97 % at a potential of -0.5 V (vs. reversible hydrogen electrode, RHE).