Oxidative Desulfurization of Aromatic Sulfur Compounds over Titanosilicates

The application of several titanosilicates to the oxidation of aromatic sulfur compounds such as thiophene, benzothiophene, dibenzothiophene, and 4,6-dimethyldibenzothiophene with H₂O₂ under mild conditions is reported. Superior to other titanosilicates, Ti-MWW demonstrates a higher activity for the oxidation of 4,6-dimethyldibenzothiophene owing to the unique pore structure of the MWW topology. The effects of solvent, temperature, catalyst amount, and H₂O₂/S ratio on the oxidation of 4,6-dimethyldibenzothiophene over this catalyst are studied in detail. The catalyst is also applied to the oxidative desulfurization of commercial diesel. The sulfur compounds in the commercial diesel were oxidized to the corresponding sulfones, which could be readily extracted by acetonitrile, resulting in a maximum sulfur removal of 88% Putting an end to sulfuring: The catalytic activity as well as shape selectivity of several titanosilicates for the oxidation of aromatic sulfur compounds is investigated. Owing to its unique pore structure, an organosilicate with the MWW topology demonstrates an activity for sulfur compounds that is superior to other titanosilicates.