Cobalt Single-Atom Anchored Tubular Graphyne for Electrocatalytic CO₂ Reduction Reaction

Electrochemical CO₂ reduction reaction through utilizing renewable electricity under mild conditions is a promising pathway toward achieving carbon neutrality. In this work, we designed a tubular graphyne functionalized with isolated Co single atom and lowered the activation energy barrier of its rate-determining step to as low as 0.46eV. The catalytic performance was systematically evaluated through density functional theory calculations. Compared with the planar graphyne functionalized with isolated Co single atom, the tubular one not only significantly improves the utilization efficiency of Co single atoms by exposing them more thoroughly, but also increases the catalytic activity of Co single atom by enhancing electron density of states at the Fermi level, which causes a higher level of activation state for the adsorbed CO₂ molecules. Furthermore, it brought about the CO₂-to-CH₄ reduction reaction pathway, resulting in remarkable catalytic activity and high methane selectivity. Our study demonstrates the efficacy of curvature engineering in enhancing the intrinsic activity of single-atom catalysts, offering a novel strategy for designing advanced carbon cycle catalysts.