Mild oxidation of bulky organic compounds with hydrogen peroxide over mesoporous TiO2-SiO2 xerogels prepared by non-hydrolytic sol-gel

The oxidation of bulky organic compounds with aqueous H2O2 over a TiO2-SiO2 xerogel catalyst prepared by a simple non-hydrolytic sol-gel route is described for the first time. Anthracene, cyclooctene, styrene, alpha-naphtol, diphenyl sulfide, dibenzothiophene and 4,6-dimethyl-dibenzothiophene were oxidized with high activity, selectivity and H2O2 efficiency at moderate temperatures (40-60 degrees C). Moreover, a similar catalytic behavior was observed when tert-butyl hydroperoxide (TBHP) was used as an oxidizing agent. These excellent catalytic performances were ascribed to the unique texture of the catalyst(specific surface area 1200 m(2) g(-1), pore volume 2.4 cm(3) g(-1), average pore diameter 15 nm) and to the stability of Ti sites after exposure to aqueous H2O2 or TBHP. (C) 2010 Elsevier B.V. All rights reserved.