Theoretical Investigation on Graphene-Supported Single-Atom Catalysts for Electrochemical CO2 Reduction

With the advantages of maximum metal utilization, single-atom catalysts (SACs) are emerging as promising catalysts in the CO2 reduction reaction (CO2RR) field. Herein, first-principles calculation is performed to investigate the CO2-to-CO conversion mechanism by a serial of transition metal single transition metal atom supported on graphene systems (TM@Grs) as a CO2 reduction catalyst. Among all SACs considered in this work, Cr@Grs exhibits a low limiting potential of −0.21 V, showing remarkable performance for CO2RR. To understand activity origin of CO2RR, we analyzed the effect of d-band centers of TM@Grs and investigated the charge transfer and bonding/antibonding states between the intermediates and TM atoms. These physical quantities provide a good explanation for the process of CO2RR and show the theoretical guidance for proper catalyst discovery and better carbon circulation.