Co–N–C supported on SiO 2 : a facile, efficient catalyst for aerobic oxidation of amines to imines

We developed a novel, facile preparation method of Co–N–C/SiO2, which was the pyrolysis of silicone gel containing metal ion and triethanolamine (TEA) prepared by sol–gel process. N2 adsorption–desorption characterization displayed the sample had high specific surface area and pore volume (220.9 m2 g−1, 0.67 mL g−1). The active Co appeared to be small particles with size of about 5 nm and was well dispersed on SiO2. And the highly dispersed cobalt and nitrogen-doped carbon in Co–N–C/SiO2 served as active phase for the oxidation of amines to imines, thus Co–N–C/SiO2 could efficiently catalyze the oxidation of amines to imines in solvent-free, air atmospheric conditions, avoiding the use of large excesses of additives, specialized oxidant and solvent.