Single-Atom-Embedded Nitrogen-Doped Graphene as Efficient Electrocatalysts for the CO₂ Reduction Reaction

Single-atom catalysts (SACs) have displayed unprecedented activity and selectivity for electrochemical CO₂ reduction reaction (CO₂RR). Herein, a series of metal single atoms embedded on nitrogen-doped graphene (M-N₄G, where M = In, Tl, Ge, Sn, Pb, Sb, and Bi) is systematically evaluated as CO₂RR electrocatalysts by density functional theory (DFT) calculations. The computational results show that most M-N₄G exhibit better CO₂RR selectivity over the hydrogen evolution reaction (HER). Ge/Pb-N₄G exhibits excellent electrocatalytic performance in the generation of HCOOH from the CO₂RR with low limiting potentials of -0.292 and -0.306 V, which surpass the performance of the vast majority of electrocatalysts. Adsorption energy of the key intermediate *HCOO can be used as an effective reactivity reaction descriptor to screen promising CO₂RR catalysts. The results of this work highlight M-N₄G as an ideal electrochemical for the electrocatalytic CO₂RR.