Oxidation of Organic Sulfur Compounds in the Presence of Heteropoly Acids Immobilized on Mesoporous Silicates

Heteropoly acids chemically immobilized on the surface of amino-functionalized mesoporous silicates of types MCM-41 and SBA-15 were studied in oxidation of model mixtures of organic sulfur compounds in the slurry mode. The synthesized catalysts were studied using a complex of physicochemical methods: low-temperature nitrogen adsorption–desorption, elemental analysis, and IR spectroscopy. The influence of the main oxidation parameters (reaction time, temperature, kind of catalyst and support, oxidant amount) on the dibenzothiophene conversion was studied. Optimum conditions of oxidation of a model dibenzothiophene mixture, ensuring exhaustive oxidation of the substrate, were found. The catalysts can be used in no less than five cycles without regeneration and activity loss.