Article ID Journal Published Year Pages File Type
65365 Journal of Molecular Catalysis A: Chemical 2014 9 Pages PDF
Abstract

•Linear relationship between oxidative desulfurization activity and the amount of silanol groups on pure mesoporous silcas.•Surface silanol groups act as the active sites of oxidative desulfurization.•Mechanism of surface silanol-mediated oxidative desulfurization of dibenzothiophene.

Ordered mesoporous silicas with structures of MCM-41, MCM-48 and SBA-15 were synthesized. Oxidative desulfurization activities of dibenzothiophene and 4,6-dimethyl dibenzothiophene on the mesoporous silicas were investigated using tert-butyl hydroperoxide as an oxidant. Textures and surface properties of the synthesized mesoporous silicas were studied by X-ray diffraction, N2-sorption, FT-IR and NH3-temeprature programmed desorption. The results show that oxidative desulfurization catalytic activities increase with surface area and surface acidity of the mesoporous silicas. Oxidative desulfurization mechanism on MCM-41 was investigated by the addition of surface silanol inhibitor such as acetic acid, water and triethylolamine or silylation of surface silanol groups using trimethylchlorosilane. A hypothetical mechanism based on surface silanol-mediated oxidation desulfurization is proposed. Oxidative desulfurization activities for Mo catalysts supported on MCM-41 were also investigated to identify the difference in oxidative desulfurization mechanism between MoO3 catalysts and pure mesoporous silicas.

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Related Topics
Physical Sciences and Engineering Chemical Engineering Catalysis
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