Preparation of CoNC catalysts via heating a mixture of cobaltporphyrin and casein for ethylbenzene oxidation

Biomass-derived cobalt-coordinated N-doped carbon (CoNC) for C–H bond oxidation is synthesized by a facile procedure based on pyrolysis of cobaltporphyrin with natural, amino acid-rich biomass casein as a supplementary nitrogen source. The catalysts are characterized by techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The obtained CoNC catalyst has a high metal content and dispersion and shows superior catalytic performance in C–H bond oxidation with molecular oxygen as oxidant under solvent-free conditions. This is attributed to the promotion of the Co–Nx moiety originating from cobaltporphyrin. Moreover, the catalyst shows remarkable stability and can be recycled several times without losing its activity.