Highly Durable and Fully Dispersed Cobalt Diatomic Site Catalysts for CO₂ Photoreduction to CH₄

Dual-atom-site catalysts (DACs) have emerged as a new frontier in heterogeneous catalysis because the synergistic effect between adjacent metal atoms can promote their catalytic activity while maintaining the advantages of single-atom-site catalysts, such as almost 100 % atomic efficiency and excellent hydrocarbon selectivity. In this study, cobalt-based atom site catalysts with a Co₂–N coordination structure were synthesized and used for photodriven CO₂ reduction. The resulting CoDAC containing 3.5 % Co atoms demonstrated a superior atom ratio for CO₂ reduction catalytic performance, with 65.0 % CH₄ selectivity, which far exceeds that of cobalt-based single-atom-site catalysts (CoSACs). The intrinsic reason for the superior activity of CoDACs is the excellent adsorption strength of CO₂ and CO* intermediates at dimeric Co active sites.