In Situ Growth of Copper Phenylacetylide Nanobelts on Copper Foil for Enhanced Electroreduction of CO2 to Multi-Carbon Products

Copper-based metal–organic composites are promising catalysts for electrochemical CO 2 reduction reaction (eCO 2 RR). However, it is difficult to prepare stable Cu + active sites in a controllable way and maintain them in the catalytic reduction. In this work, a (CuPA-Ag)/Cu electrode was prepared by the ion sputtering of Ag NPs on the copper foil, followed by the in situ growth of Ag NP-grafted CuPA NBs on its surface. The electrode possessed a large amount of Cu + active sites due to the strong σ-donation and π-backdonation interactions between the phenylacetylene ligand and Cu + , which significantly improved the catalytic performances. Using the optimized electrode and reaction conditions, the eCO 2 RR achieved Faraday efficiencies of 44.5% for C 2 H 4 and 56.5% for C 2+ products in the H cell. With periodic supplementation of the CO 2 source, the eCO 2 RR maintained an FE C 2 H 4 above 40% for 11 h. Its superior catalytic performance originated from the densely stacked nanobelt structures with a large electrochemical surface area and enhanced electron transfer, the synergistic effect between Ag and Cu + to promote the CO 2 absorption and C–C coupling, and the hydrophobicity of CuPA to inhibit the hydrogen evolution reaction.