Copper Electrocatalyst Produced by Cu₂(OH)₂CO₃-Mediated In Situ Deposition for Diluted CO₂ Reduction to Multicarbon...

Pure CO₂ is commonly used in most of the current studies for electrochemical CO₂ reduction which will need a further cost of gas purification and separation. However, the limited works on diluted CO₂ reduction are focused on CO or CH₄ production other than C₂ products. In this work, copper electrocatalysts were prepared by Cu₂(OH)₂CO₃-mediated in situ deposition for diluted CO₂ reduction to multicarbon products. Using in situ Raman spectroscopy, constant amounts of CO and OH* were observed on the catalyst surface, which could effectively suppress the high kinetics of hydrogen evolution and promote C-C coupling, especially under the condition of diluted CO₂ reduction. The optimized Cu catalyst achieves a C₂ Faradaic efficiency as high as 60.72% in the presence of merely 25% CO₂, which is almost equivalent to that observed with pure CO₂.