Silica-gel Supported V Complexes: Preparation, Characterization and Catalytic Oxidative Desulfurization

In this manuscript, a series of catalyst SG(n)-[(VO2)-O-V-PAMAM-MSA] (SG = silica gel, PAMAM = polyamidoamine, MSA = 5-methyl salicylaldehyde, n = 0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and inductive coupled plasma emission spectrometer (ICP) etc. XPS revealed that the metal V and SG(n)-PAMAM-MSA combined more closely after the formation of Schiff base derivatives. Their catalytic activities for oxidation of dibenzothiophene were evaluated using tert-butyl hydroperoxide as oxidant. The results showed that the catalyst SG(2.0)-[(VO2)-O-V-PAMAM-MSA] presented good catalytic activity and recycling time. Meanwhile, the optimal condition for the catalytic oxidation of SG(2.0)-[(VO2)-O-V-PAMAM-MSA] was also investigated, which showed that when the oxidation temperature was 90 degrees C, time was 60 mm, the O/S was 3 : 1, and the mass content of catalyst was 1%, the rate of desulfurization could reach 85.2%. Moreover, the catalyst can be recycled several times without significant decline in catalytic activity.