Photodriven CO dimerization on Cu2O from an electronic-structure perspective†
Electrochemically driven CO2 reduction into alcohols and hydrocarbons is a topic of intense study. Photocatalytic approaches, which instead are powered by light, are also reported, but these generally rely on two-component catalysts and yield only moderately reduced products with a single carbon atom. In this report, we use density functional theory, including its linear-response time-dependent implementation, to investigate the feasibility of photocatalytically driving the dimerization of CO chemisorbed on Cu2O, a crucial step in the chemical conversion of CO2 into C2 products, such as ethanol and ethylene. We find that CO dimerization into OCCO is greatly aided by the photoinduced population of a low-lying LUMO that is bonding with respect to the C–C bond of two adjacently chemisorbed CO molecules.