Silver modified copper foam electrodes for enhanced reduction of CO2 to C2+ products

Electrochemical CO2 reduction reactions (CO2RRs) have been recognized as a promising solution to environmental and energy problems due to their ability to convert intermittent renewable electricity into hydrocarbon fuels and value-added chemicals. Copper has a unique ability to electrochemically reduce CO2 to produce C2+ hydrocarbon products compared to other metals. However, it is still suffering from low Faraday efficiency (FE) limitations for specific products. Herein, we have prepared an Ag-modified Cu/CuO–Ag catalyst with a porous structure via a galvanic replacement reaction method, which reduced CO2 to C2+ products with the FE of 52.5% at −1.1 V (vs. RHE). The experimental results and density functional theory (DFT) calculations show that the addition of Ag in Cu is beneficial to increasing the coverage of *CO on the Cu surface, which can decrease the potential barrier energy of the C–C coupling reaction and favor the generation of C2+ products. The results of this study may be helpful to the design of efficient tandem catalysts for electrochemical CO2 reduction.