Atomically Dispersed Au-Assisted C–C Coupling on Red Phosphorus for CO₂ Photoreduction to C₂H₆

Single-atom catalysts have exhibited great potential in the photocatalytic conversion of CO₂ to C₂ products, but generation of gaseous multi-carbon hydrocarbon products is still challenging. Previously, supports of a single atom consist of multiple elements, making C-C coupling difficult because the coordination environment of single-atom sites is diversified and difficult to control. Here, we steer C-C coupling by implanting an Au single atom on the red phosphorus (Au₁/RP), support with uniform structure composed of a single element, lower electronegativity, and better ability to absorb CO₂. The electron-rich phosphorus atoms near the Au single atoms can function as active sites for CO₂ activation. The Au single atom can effectively reduce the energy barrier of C-C coupling, boosting the reaction kinetics of the formation of C₂H₆. Notably, the C₂H₆ selectivity and turnover frequency of Au₁/RP reach 96% and 7.39 h^-1 without a sacrificial agent, respectively, which almost represents the best photocatalyst for C₂ chemical synthesis to date. This research will provide new ideas for the design of high-efficiency photocatalysts for CO₂ conversion to C₂ products.