Nitrogen-doped carbon cobalt grafted on graphitic carbon nitride catalysts with enhanced catalytic performance for ethylbenzene oxidation

Abstract

Nitrogen-doped carbon cobalt (Co-N-C) grafted on graphitic carbon nitride (g-C3N4) catalysts (Co-N-C/g-C3N4) were synthesized via pyrolysis of cobalt(II) 5,10,15,20-tetraphenylporphyrin (CoTPP) immobilized on graphitic carbon nitride in N2 atmosphere. These catalysts were characterized by techniques such as UV–vis, FT-IR, TG-DTA, XRD, SEM, TEM, HRTEM, BET and XPS. The catalytic performance of Co-N-C/g-C3N4 for selective oxidation of ethylbenzene has been investigated. As a result, when the mass ratio of CoTPP to g-C3N4 is 20%, the conversion of ethylbenzene over Co-N-C/g-C3N4 is 28.0%, nearly 2.3 and 1.9 times than those over pure g-C3N4 and Co-N-C, respectively. Moreover, better stability is also performed after 6 runs (i.e., 20.3% conversion of ethylbenzene and 71.1% of selectivity to acetophenone). The results show that the superior catalytic activity and stability maybe attributed to the Co-Nx active site and the synergistic effect between Co-N-C and g-C3N4.