2003 Volume 46 Issue 6 Pages 379-382
An immobilized 12-tungstophosphoric acid on an anion exchange resin (TPA/AER) catalyzes the oxidation of dibenzothiophene and 4, 6-dimethyldibenzothiophene with H2O2 in acetonitrile (MeCN) to give the corresponding sulfones as the major product. The oxidation rates increased with increasing amounts of H2O2 and TPA/AER. TPA/AER is reusable since the catalytic activity was not reduced even during the fifth cycle of use. TPA/AER acts as a catalyst for the oxidation of dibenzothiophenes in an octane/MeCN biphasic system as well. The major oxidation products were also the sulfones, which were mainly distributed in the MeCN phase. In TPA/AER-catalyzed oxidative desulfurization of diesel oil containing 330 ppm sulfur, the reduction of the sulfur content was enhanced with increasing amounts of immobilized TPA per unit weight of AER and the sulfur content was reduced to below 50 ppm. The sulfur content was further decreased by solvent extraction with MeCN.
