Atomic alkali metal anchoring on graphdiyne as single-atom catalysts for capture and conversion of CO2 to HCOOH

Carbon dioxide electrochemical reduction reaction (CO2RR) with proton-electron pair delineates an intriguing prospect for converting CO2 to useful chemicals. Here by means of first-principle computations, the geometric constructions, electronic structures, and CO2RR catalytic performance of graphdiyne with single adsorbed alkali metal atoms (AM@GDY) are systematically investigated. The calculated results validate that the AM@GDY complexes possess excellent stability. The catalytic performance is correlated with the size of alkali metal ions. The adsorption free energies of CO2 on AM@GDY surfaces show that the Li@GDY and Na@GDY can spontaneously capture CO2 molecules. The interactions between *OCHO specie and AM@GDY are stronger than that between *COOH and AM@GDY, which can promote the CO2 reduction to HCOOH. The AM@GDY complexes could efficiently convert CO2 into HCOOH with high-selectivity, and the limiting potentials are - 0.56 V on Li@GDY and - 0.16 V on Na@GDY monolayers. The present findings not only highlight the importance of AM@GDY for CO2 electroreduction but also indicate that they are potentially single-atom electrocatalysts.