Entrapment of peroxophosphotungstate in SBA-15 by silylation and its catalytic efficiency in the epoxidation of soybean oil

The efficient catalysts were designed to allow the entry and release of reactants and products into the mesoporous SBA-15 in which the active sites, peroxophosphotungstate, were entrapped by silylation with three different silylating agents (C3, C5, and C8 arm). The as-prepared catalysts were characterized by elemental analysis, ICP analysis, TGA, XRD, N2 adsorption/desorption, SEM, TEM, and FT-IR spectra. Their catalytic performances were tested for the epoxidation of soybean oil using different parameters such as temperature, H2O2 to unsaturation molar ratio, catalyst loading and stirring speed. The resulting epoxidized soybean oil was analyzed qualitatively and quantitatively by FT-IR and 1HNMR. The results confirmed that the catalyst silylated with C8 arm is promising for the synthesis of epoxides of long-chain carbon and reusable at least three times without obvious decrease in activity. Moreover, use of H2O2 oxidant and free of solvent in the epoxidation reaction are the main advantages of these catalysts.