Investigation of Pyridine as a Cocatalyst for the CO2 Reduction Reaction on the Cu2O Cathode Surface

Photoelectrocatalytic CO2 reduction is a way to capture carbon and store solar energy at the same time. A Cu2O photoelectrode is a nonhazardous material based on relatively abundant elements possessing both good multielectron transfer properties and high light absorption efficiency. However, the catalytic-active (110) facet and the inert (100) facet are found to be easily oxidized into CuO in aqueous solution, causing a stability issue, while the Cu2O (111) facet is stable but exhibits poor selectivity of the CO2 reduction reaction (CO2RR). Recently, pyridine (Py) is reported as a cocatalyst that can improve the photocatalytic performance of cathode materials for CO2RR. We therefore perform first-principles calculations to investigate the Py cocatalytic process on the Cu2O (111) surface for CO2RR and predict that the Py-derived catalytic intermediates formed via electronic transfer from the surface could potentially enhance the selectivity of the Cu2O surface toward CO2 reduction while maintaining the promising stability of the Cu2O (111) facet.