Modification Of Silica Based Materials And Their Application On Aicd Catalysis And Oxidative Desulfurization

This thesis was focused on two sections. In the first section, mesoporous organic-inorganic hybrids were synthesized, characterized and applied in the acetal reaction. In the second section, oxidative desulfurization of gasoline and diesel were carried out by Ti-SiO₂ and H₂O₂.In the first section, with direct-synthesis and post-synthesis, sulfonic functionalized mesoporous organic-inorganic hybrids were synthesized by introducing the -SO₃H group into MCM-41 directly. The sulfonic functionalized mesoporous organic-inorganic hybrids maintain the ordered mesopores and the high surface areas, which were approved by XRD, TEM and BET. These hybrids containing sulfonic group showed good catalytic activity for the acetal reaction. The mesoporous organic-inorganic hybrid prepared by post-synthesis gave 2-phenyl- [1,3]-dioxolane in 80 % yield and the mesoporous organic-inorganic hybrid prepared by direct-synthesis gave 2-phenyl-[1,3]-dioxolane in 74 % yield.The sulfonic functionalized mesoporous organic-inorganic hybrid (MCM-SO3H) was synthesized by reaction of (3-mercaptopropyl)trimethoxysilane with MCM-41 and subsequent oxidation by H₂O₂. XRD, FT-IR, BET characterizations showed that the hybrid (MCM-SO3H) still maintained the mesopores. The amount of the acid site of MCM-SO₃H measured by NaOH titration was 0.40mmolH⁺/g. The mesoporous organic-inorganic hybrid (MCM-SO₃H) was an efficient catalyst for pinacol rearrangement reaction under mild reaction condition. The effects of temperature, reaction time, amount of catalyst and polarity of solvent on the catalytic properties were also investigated. The conversion of pinacol and the selectivity of pinacolone were improved by increasing reaction temperature, prolonging reaction time and increasing amount of catalyst. Higher conversion of pinacol and selectivity of pinacolone were achieved by using medium polarity solvents.In the second section, Ti-SiO₂ catalysts were synthesized by grafting titanium onto the surface of silica. The Ti-SiO₂ catalysts had high activity for the oxidation of organic sulfur compounds. The order of the oxidative activity of the sulfur compounds was as...