Electronic perturbation of Cu nanowire surfaces with functionalized graphdiyne for enhanced CO reduction reaction.

Electronic perturbation of the surfaces of Cu catalysts is crucial for optimizing electrochemical CO reduction activity, yet still poses great challenges. Herein, nanostructured Cu nanowires (NW) with fine-tuned surface electronic structure are achieved via surface encapsulation with electron-withdrawing (-F) and -donating (-Me) group-functionalized graphdiynes (R-GDY, R = -F and -Me) and the resulting catalysts, denoted as R-GDY/Cu NW, display distinct CO reduction performances. electrochemical spectroscopy revealed that the *CO (a key intermediate of the CO reduction reaction) binding affinity and consequent *CO coverage positively correlate with the Cu surface oxidation state, leading to favorable C-C coupling on F-GDY/Cu NW over Me-GDY/Cu NW. Electrochemical measurements corroborate the favorable CH production with an optimum C selectivity of 73.15% ± 2.5% observed for F-GDY/Cu NW, while the predominant CH production is favored by Me-GDY/Cu NW. Furthermore, by leveraging the *Cu-hydroxyl (OH)/*CO ratio as a descriptor, mechanistic investigation reveals that the protonation of distinct adsorbed *CO facilitated by *Cu-OH is crucial for the selective generation of CH and CH on F-GDY/Cu NW and Me-GDY/Cu NW, respectively.