Electrochemical CO2 Reduction on Cu-Based Monatomic Alloys: A DFT Study

In recent years, single-atom alloy catalysts (SAAs) have received much attention due to the combination of structural features of both single-atom and alloy catalysts, as well as their efficient catalytic activity, high selectivity, and high stability in various chemical reactions. In this work, we designed a series of Cu-based SAAs by doping isolated 3d transition metal (TM1) atoms on the surface of Cu(111) (TM1 = Fe, Co, Ru, Rh, Os and Ir), in which Ir1/Cu(111) SAAs are considered to be the most stable among 3d-series SAAs due to their optimal binding energy (Eb). The density of states of SAAs have been systematically investigated to further discuss structural properties. Based on density functional theory calculations, the activity and selectivity of Ir1/Cu(111) SAAs are investigated for electrocatalytic CO2 reduction reaction (CO2RR). The initial hydrogenation of CO2 on Ir1/Cu(111) SAAs can form *CO intermediates, which will be further to CH4 production by the pathway of *CO → *CHO → *CHOH → *CH2OH → *CH2 → *CH3 → CH4. This study provides theoretical insights for the rational design of selective Cu-based monatomic alloy catalysts.