DFT Study of CO2 Reduction Reaction to CH3OH on Low-Index Cu Surfaces

Abstract

The electrochemical reduction of CO2 is an efficient method to convert CO2 waste into hydrocarbon fuels, among which methanol is the direct liquid fuel in the direct methanol fuel cells (DMFC). Copper is the most widely used catalyst for CO2 reduction reaction (CO2RR); the reaction is affected by the surface morphology of the copper. Here, the morphology effect and the mechanism of CO2RR on three typical low-index Cu (100), Cu (110) and Cu (111) surfaces are studied. According to our results, Cu (110) provides the optimum surface for the CO2RR via CO2 → *COOH → *CO → *CHO → *CH2O → *CH2OH → CH3OH pathway, where the reduction reaction of CO2 to *COOH is the potential-determining step (PDS). This is because Cu (110) has the highest d band center, which promotes the adsorption of *COOH.