Electrochemical synthesis of formamide by C–N coupling with amine and CO2 with a high faradaic efficiency of 37.5%

N,N-Dimethylformamide (DMF) is a versatile chemical and universal solvent that is commonly synthesized from carbon monoxide and dimethylamine (DMA) under high temperature and pressure. However, this process leads to a large amount of carbon emissions. Herein, we propose an electrochemical strategy to directly convert carbon dioxide (CO2) and DMA to DMF under ambient conditions. Loading palladium (Pd) onto copper (Cu) nanosheet catalysts with Cu vacancies (Pd/Cu-VCu) enabled the efficient synthesis of DMF, and the maximum yield and faradaic efficiency reached 385 mmol·h−1·gcat. −1 and 37.5%, respectively. In situ spectroscopy and density functional theory calculations indicated that Cu vacancies (Cu-VCu) promoted the adsorption of CO2 on the catalyst surface, followed by its spontaneous coupling with DMA to form the C–N bond. Pd nanoparticles accelerated the electrochemical reduction of the intermediate ∗OCN(CH3)2OH to ∗OCHN(CH3)2OH, leading to highly efficient DMF electrosynthesis. This work paves the way for the synthesis of sustainable high-value organic nitrogen compounds from CO2.