Electrochemical CO2 reduction on graphdiyne: a DFT study

Abstract

Graphdiyne, a new member of the 2D carbon family, has exhibited interesting physiochemical properties attracting academic attention. Its π-conjugated structure with unique sp–sp² bonding demonstrates a great potential for electrocatalysis. As electrochemical CO₂ reduction reaction (CO₂RR) has been recognized as a highly promising CO₂ utilization technique, the search for active catalysts is critical for the development of CO₂RR. Herein, using density functional theory calculations, we studied the activity and selectivity of graphdiyne towards CO₂RR. The reaction free energy diagrams are thoroughly investigated, and the results show that the hybridization of sp–sp² is crucial for high activity owing to the strong adsorption of the *COOH intermediate. Moreover, nitrogen-doping on graphdiyne further improves the activity and selectivity towards CH₃OH and CH₄ products. The lowest limiting potential of CH₃OH on nitrogen-doped graphdiyne is reduced to −0.46 V. The current study predicts the high activity of graphdiyne towards CO₂RR, and illustrates the key role of hybridization on the reactivity of the carbon catalysts.