2D Carbon Nitride as Support of Single Cu, Ag, and Au Atoms for Carbon Dioxide Reduction Reaction

Abstract

Electrochemical conversion of CO2 into added-value chemicals is an important approach to recycle CO2. In this work, we have combined the most efficient metal catalysts for this reaction (Cu, Ag, and Au) considering dispersed single atom particles on the two-dimensional carbon nitride support, with the aim of exploring their performance in the CO2 reduction reaction. We report here density functional theory computations showing the effect of single metal atom particles on the support. We find that bare carbon nitride needs a high overpotential to overcome the barrier for the first proton-electron transfer while the second is exergonic. The deposition of single metal atoms enhances the catalytic activity of the system, being the first proton-electron transfer favored in energy, although strong binding energies were found for CO adsorptions with Cu and Au single atoms. Our theoretical interpretations are consistent with the experimental evidence, where the competitive H2 generation is favored due to these strong binding energies. Our computational study paves the road to find suitable metals able to catalyze the first proton-electron transfer reaction together with moderate binding energies of reaction intermediates, to promote the spillover to the carbon nitride support and work as bifunctional electrocatalysts