Catalytic Hydroxylation of Benzene to Phenol with Vanadium Containing Hexagonal Mesoporous Silica

Abstract

Vanadium containing hexagonal mesoporous silica(V-HMS) catalysts with different vanadium contents were prepared by sol-gel method with ammonium metavanadate used as the starting material of vanadium,and the obtained catalysts were characterized by powder X-ray diffraction(XRD),N2-adsorption techniques and H2-temperature programmed reduction(H2-TPR).The catalytic performance for hydroxylation of benzene with H2O2 to phenol was investigated.The results indicated that vanadium species was successfully incorporated into the framework of HMS,and a uniform mesoporous structure and good dispersion were found.Meanwhile,V-HMS exhibited superior catalytic performance in the hydroxylation of benzene to phenol.The good dispersion and isolated vanadium species were beneficial to the high catalytic activity of hydroxylation of benzene to phenol.When the mass fraction of V(5.8% mass fraction)-HMS was 2%,the reaction temperature was 60 ℃,and the reaction time was 5 h,the yield and selectivity of phenol achieved 18.55% and 100%,respectively.