Direct electro-synthesis of valuable C=N compound from NO

Cyclohexanone oxime ( CHO), a key C=N organic compound in the manufacture of nylon 6, is conventionally synthesized via amultistep process that consumes expensive NH3 and H-2 under harsh conditions. Herein, we report the direct electro-synthesis of CHO from low-cost NO, H2O, and cyclohexanone over a carbon catalyst under ambient conditions. A high Faradaic efficiency of 44.8% and a formation rate of 10.7 mg cm(-2) h(-1) for CHO were achieved at -0.4 V versus the reversible hydrogen electrode through optimizing the surface hydrophobicity of the catalyst to facilitate diffusion of reactants. Controlled experiments and 15N- labeling tests verified that the nitrogen in the CHO product originates from NO. Density functional theory calculations showed that the armchair edge of carbon could be the active site with a reaction mechanism following NO/ NO*/ HNO*/ HNOH*/ NH2OH/ CHO. This work suggests a direct, green, and low-cost synthesis strategy for high- value CHO from pollutant NO.