RESUMO
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.
RESUMO
Electrochemical reduction of CO2 to ethylene using renewable electricity is an attractive approach for sustainable carbon recycling. In situ generation of defects in catalysts is found to be a promising method to guarantee high ethylene production from CO2 with high stability. In this study, copper nanowires are prepared in situ with a high density of defects for electrocatalytic CO2 reduction. These defects effectively improve C-C coupling, thus realizing a remarkable performance toward CO2 reduction to C2 products. The obtained copper nanowires showed a high selectivity of â¼79% for C2 products and >58% for C2H4. More importantly, a significantly wide potential window of 500 mV was realized for the selective production of C2H4 with FE(C2H4) >55%. Finally, in situ Raman spectroscopy revealed that Cu0 is the real reactive site for the electrocatalytic CO2 reduction reaction.
