Epoxidation of styrene catalyzed by mesoporous propylthiol group-functionalized silica supported manganese(III) salen complexes with different pore morphologies

Mesoporous propylthiol group-functionalized silica supported manganese(III)-salen complexes with 2D hexagonal p6mm and 3D interconnected sponge-like structures were prepared by a multistep grafting method by using tetraethyl orthosilicate (TEOS) or 1,2-bis(trimethoxysilyl)ethane (BTMSE) as a silica source and 3-mercaptopropyltriethoxysilane (MPTES) as a linker reagent. The structure, morphology, and porosity of the resulting hybrid materials were well-characterized by spectroscopy method, X-ray diffraction analysis, transmission electron microscopy, and nitrogen physisorption measurement. Subsequently, their oxidation catalytic activity and stability were evaluated through the epoxidation of styrene by using aqueous NaClO as the oxygen source, and the influences of sulfur atom in the hybrid materials, textural properties and pore morphologies of the materials, and the kinds of the substituents in the diimine bridges of the manganese(III)-salen complexes on the catalytic activity of the hybrid materials were discussed.

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► Mn(salen)/pr-S–SiO2 hybrid materials with various pore morphologies were prepared.
► The materials exhibited excellent catalytic performance towards styrene epoxidation.
► Pore diameter and structural ordering influence catalytic activity of the materials.