Solvent-Free Melting-Assisted Pyrolysis Strategy Applied on the Co/N Codoped Porous Carbon Catalyst

Abstract

From the current demand for aromatic ketones, economical and environmentally friendly renewable catalysts are highly economical for the efficient selection of aralkyl oxides to form the corresponding aromatic ketone compounds. Yet, since the preparation of the Co–N–C catalyst is complicated at present, it is difficult to be widely applied to the oxidation of arylalkanes. In this study, a one-step solvent-free melting-assisted heat-treatment strategy is adopted to synthesize cobalt and nitrogen codoped carbon catalysts from sucrose, 5-(4-carboxyphenyl)-10,15,20-triphenylcobalt porphyrin (CoCPTPP), and KIT-6. Thanks to the interaction between the silicon hydroxyl of KIT-6 and the carboxyl hydroxyl of CoCPTPP as well as the distinctive properties of CoCPTPP with Co–N4 structures, the Co species in the as-synthesized catalysts are uniformly dispersed on carbon materials. Hereafter, the catalyst showed a high efficiency for the oxidation of arylalkane, e.g., the conversion rate of ethylbenzene is 96% and the selectivity of acetophenone is 99%. According to the characterizations including transmission electron microscopy etc, the results show that a porous special structure and thriving Co–Nx active sites in the catalysts is the main reason for the catalyst’s good catalytic activity and stability. In addition, the catalyst can also be used for the oxidation reaction of various aromatic hydrocarbon substrates with high catalytic activity.