Co single atom and cluster loaded heteroatom-doped graphene electrocatalysts for CO₂ to CO or HCOOH

Non-noble-metal single-atom and cluster catalysts exhibit respective advantages, while the performance of their multi-atom composite catalysts remains unclear. Herein, via density functional theory, we designed a composite catalyst by loading metal clusters on heteroatom-modified SACs. Using 2–5-atom Co clusters (Co_n-SA, n = 2–5) and F/N/Co synergistic effects, we screened catalytic activity and verified structural robustness through calculations of adsorption energies and density of states. Moreover, Gibbs free energy and electronic structure analyses further confirm the superior catalytic performance of Co₃-SA for CO production in CO₂ reduction reaction and Co₂-SA for HCOOH generation. Furthermore, effective suppression of the competing hydrogen evolution reaction is achieved. The current study emphasizes the pivotal function of the d-band center in determining product selectivity, together with the activity and selectivity exhibited by Co₂-SA and Co₃-SA catalysts in CO₂ reduction reaction (CO₂RR). This theoretical research offers feasible references for rationally developing cost-efficient, high-activity catalysts.