Carbonized Yolk-shell Metal-Organic Frameworks for Electrochemical Conversion of CO2 into Ethylene

With the excessive consumption of fossil fuels and the massive emission of CO 2 , it has led to a series of environmental crises posing a serious threat to sustainable development. Electrochemical CO 2 reduction reaction (CO 2 RR) to ethylene helps solve these serious environmental crises. Herein, we report the synthesis of a copper-based electrocatalyst by pyrolysis of yolk-shell structured HKUST-1 with partial substitution of trimesic acid by benzimidazole(nitrogen source). The electrocatalyst exhibits an ethylene Faradic efficiency(FE) of 25.8% and a partial ethylene current density of 23.7 mA/cm 2 , in addition, the electrocatalyst can maintain stable performance during 10 h of electrolysis, which are all better than those of the electrocatalyst without nitrogen dopant. According to electrochemical measurements and X-ray photoelectron spectroscopy(XPS), we propose that the nitrogen dopant plays an effective role in stabilizing Cu(I) species and promoting CO 2 molecules activation, as well as suppressing the reduction of Cu(I) species during electrolysis. Eventually, the performance of the electrocatalyst toward CO 2 RR is studied in a flow cell. This work provides a new route for the design of Cu-based electrocatalyst toward electrochemical CO 2 conversion into ethylene.