Achievements and challenges of copper-based single-atom catalysts for the reduction of carbon dioxide to C2+ products.

Copper is the only metal that can convert CO 2 into C2 and C2+ in electrocatalytic carbon dioxide reduction (CO 2 RR). However, the Faraday efficiency of CO 2 conversion to C2 and C2+ products at high current densities is still low, which cannot meet the actual industrial demand. Here, the design methods of single-atom copper catalysts (including regulating the coordination environment of single-atom copper, modifying the carbon base surface and constructing diatomic Cu catalysts) are reviewed, and the current limitations and future research directions of copper-based single-atom catalysts are proposed, providing directions for the industrial conversion of CO 2 into C2 and C2+ products.