Laser-fabricated channeled Cu6Sn5/Sn as electrocatalyst and gas diffusion electrode for efficient CO2 electroreduction to formate

Formate synthesis by CO2 electroreduction reaction (CO2RR) has been considered as a promising strategy for mitigating the excessive CO2. Here, we synthesize Cu6Sn5 alloy on Sn foil (Cu6Sn5/Sn) and gas diffusion electrode (GDE) using laser irradiation. Cu6Sn5/Sn exhibits high formate faradaic efficiency (FEformate) of 87.2% and remains stable at 28.69 mA cm(-2) over 14 h. Further, with the help of laser drilling, the channeled Cu6Sn5/Sn used directly as GDE shows increased current density (118 mA cm(-2)) and steady FEformate (86.69%) in flow cell. Density functional theory (DFT) calculations reveal that the high performance of Cu6Sn5/Sn benefits from the appropriate binding energy of the key intermediates *OCHO. Meanwhile, COMSOL simulation results of CO2 concentration and electric field distribution combined with the results of kelvin probe force microscopy (KPFM) prove that CO2RR prefers to occur around the channels of electrode. More importantly, this laser irradiation method is also available to synthesize other alloy electrocatalysts.

Automated summary

Research shows that synthesizing Cu6Sn5 alloy using laser irradiation can improve the efficiency and stability of CO2 electroreduction reaction. Laser drilling further increases the current density and stable formate production efficiency, which is attributed to appropriate binding energy of the intermediates and the channels of the electrode.