Active and efficient Co-N/C catalysts derived from cobalt porphyrin for selective oxidation of alkylaromatics

Abstract

The development of highly active and efficient heterogeneous catalytic oxidation systems has become an attractive research area. In this study, nano cobalt-coordinated nitrogen-doped carbon catalysts (Co-N/C), which were prepared by the pyrolysis of cobalt porphyrin supported on carbon black precursor, were used as highly active catalysts for the oxidation of hydrocarbons with tert-butyl hydroperoxide as the oxidant. The results showed that the catalyst was efficient in the selective oxidation of a variety of saturated (including primary, secondary, and tertiary) CH bonds. The catalyst displayed the best catalytic performance, which was comparable to those for previously reported metal oxide catalysts and even better. The resultant Co-N/C catalysts were characterized in detail by XRD, nitrogen adsorption/desorption isotherms, TEM, SEM and XPS. The homogeneous distribution of the Co species and interactions between the Co-N species could improve the synergistic effect between the CoO, CoN and NC species, which led to their excellent catalytic performance. A first order kinetics was observed for the reaction with the apparent activation energy for ethylbenzene oxidation was 22.2±2.1kJmol−1.