Constructing Cu-C Bonds in a Graphdiyne-Regulated Cu Single-Atom Electrocatalyst for CO 2 Reduction to CH 4 .

Regulating intermediates through elaborate catalyst design to control the reaction direction is crucial for promoting the selectivity of electrocatalytic CO 2 -to-CH 4 . M-C (M=metal) bonds are particularly important for tuning the multi-electron reaction; however, its construction in nanomaterials is challenging. Here, via rational design of in situ anchoring of Cu SAs (single atoms) on the unique platform graphdiyne, we firstly realize the construction of a chemical bond Cu-C (GDY). In situ Raman spectroelectrochemistry and DFT calculations confirm that due to the fabrication of the Cu-C bond, during CO 2 reduction, the formation of *OCHO intermediates is dominant rather than *COOH on Cu atoms, facilitating the formation of CH 4 . Therefore, we find that constructing the Cu-C bond in Cu SAs/GDY can supply an efficient charge transfer channel, but most importantly control the reaction intermediates and guide a more facile reaction pathway to CH 4 , thereby significantly boosting its catalytic performance. This work provides new insights on enhancing the selectivity for CO 2 RR at the atomic level.