Vanadium supported on graphitic carbon nitride as a heterogeneous catalyst for the direct oxidation of benzene to phenol

A series of graphitic carbon nitride supported vanadium catalysts ( x V/g-C 3 N 4 ) with different vanadium contents ( x /%) were prepared by impregnation. XRD, FT-IR, TEM, TG-DTG, nitrogen adsorption and XPS characterizations were conducted which revealed a strong interaction between the vanadium species and g-C 3 N 4 support. 8V/g-C 3 N 4 exhibited the highest activity and showed stable recyclability in the benzene hydroxylation reaction with a benzene conversion of 24.6% and phenol selectivity of 99.2% under the optimized conditions. The excellent catalytic performance of x V/g-C 3 N 4 was due to the integration of vanadium species with high catalytic activity and the g-C 3 N 4 support in their interaction with the benzene substrate