Influence of temperature on hydroxylation of benzene to phenol using molecular oxygen catalyzed by V/SiO2

Effect of temperature on hydroxylation of benzene to phenol with molecular oxygen as an oxidant was studied over V/SiO2 using different reductants. The V/SiO2 with highly dispersed vanadium species was prepared by a sol-gel process and characterized by diffuse reflectance UV-Vis and ESR. This work shows that the onset temperature range of benzene hydroxylation and the temperature reaching the maximum phenol yield differ corresponding to each reductant. The reducing capacity of reductant can be shown by changing temperature and affects, in turn, benzene conversion, product selectivity, and the amount of leaching of V species. (C) 2013 Elsevier B.V. All rights reserved.