Emerging dual-atomic-site catalysts for electrocatalytic CO2 reduction

The electrochemical CO2 reduction reaction (CO2RR) to yield high-value added fuels and chemicals provides a promising approach towards global carbon neutrality. Constant endeavors have been devoted to the exploration of high-efficiency catalyst with rapid reaction kinetics, low energy input, and high selectivity. In addition to the maximum metal atomic utilization and unique catalytic performance of single-atom catalyst (SAC), dual-atomic-site catalysts (DASCs) offer more sophisticated and tunable atomic structure through the modulations of another adjacent metal atom, which can bring new opportunities for CO2RR as a deeper extension of SACs and have recently aroused surging interest. In this review, we highlight the recent advances on DASCs for enhancing CO2RR. First, the classification, synthesis, and identification of DASCs are provided according to the geometric structure and electronic configuration of dual-atomic active sites. Then, the catalytic applications of DASCs in CO2RR are categorized based on marriage-type, hetero-nuclear, and homo-nuclear dual-atomic sites. Particularly, the structure-activity relationship of DASCs in CO2RR is elaborately summarized through systematically analyzing the reaction pathways and the atom structures. Finally, the opportunities and challenges are proposed for inspiring the design of future DASCs with high structural accuracy and high CO2RR activity and selectivity.