Pause electrolysis for acidic CO2 reduction on 3-dimensional Cu

Electrochemical CO 2 reduction reaction (CO 2 RR) exhibits remarkable potential in producing valuable chemicals with renewable energy. Operating CO 2 RR in acidic media is beneficial to solve the issue of low carbon utilization brought by (bi)carbonate formation at the cathode. Suppressing the competing hydrogen evolution reaction and achieving stable CO 2 RR performance remains challenging. Herein, we constructed a 3-dimensional Cu (3D-Cu) gas diffusion electrode (GDE) to achieve efficient C 2 H 4 production with a partial current density ( j C2H4 ) of over 470 mA cm −2 and a Faradaic efficiency (FE C2H4 ) of 40%. With pause electrolysis, the decay rate of the j C2H4 is only half that of the traditional constant electrolysis. The GDE after constant electrolysis was found to suffer from severe salt formation, leading to the decreased activity and poor stability.