Removal of refractory organosulfur compoundsviaoxidation with hydrogen peroxide on amorphous Ti/SiO2catalysts

Abstract

Efficient removal of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (DMDBT) has been successfully achieved via oxidation with hydrogen peroxide in liquid phase using an amorphous silica-loaded titanium oxide catalyst. Both BT and DBT are easily oxidized to the corresponding sulfones, however in the case of DMDBT the steric hindrance of the alkyl groups makes the approach of the S-atom to the catalyst active centre (an isolated Ti(IV) species) difficult and therefore its reactivity is inhibited. The concentration of the organosulfur compound, the H₂O₂ concentration and the nature of the solvent play a key role in the rate of S-removal.