Direct hydroxylation of benzene to phenol using H2O2 as an oxidant over vanadium-containing nitrogen doped mesoporous carbon catalysts

Abstract

Highly ordered nitrogen doped mesoporous carbon (NC) was synthesized via a hard template method using hexamethylenetetramine as the precursor and KIT-6 as the template. The NC materials calcined at different temperatures were used as supports to prepare a series of vanadium containing catalysts by the impregnation method. The integration of the highly ordered three-dimensional (3D) mesostructure, the hydrophobic surface with an open π-conjugated system, the abundant defects introduced by nitrogen related functionalities, and the highly dispersed vanadium species made the catalysts highly efficient in the benzene hydroxylation reaction using H₂O₂ as an oxidant. By optimizing the preparation and reaction conditions, a maximum benzene conversion of 31.0% and a phenol selectivity of 97.2% were obtained over a 4.2V/NC-600 catalyst, which was superior to the activity of the vanadium supported two-dimensional (2D) hexagonal mesoporous carbon with an amorphous framework.