Co–N–C supported on SiO2: a facile, efficient catalyst for aerobic oxidation of amines to imines

Abstract

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.