Efficient and stable PS-SO3H/SiO2 hollow nanospheres with tunable surface properties for acid catalyzed reactions

Abstract

Facile synthesis of hybrid solid acids with finely engineered surface properties was successfully realized via sulfonation of polystyrene (PS) dispersed in nanopores of silica hollow nanosphere modified with different organic group. It was found that octyl or perfluorinated octyl could efficiently increase the surface hydrophobicity of the hybrid solid acids. Benefited from the facile adjustability of the surface properties, the catalytic performance of the solid acids could be readily improved in both the esterification of lauric acid with ethanol and the transterification between tripalmitin and methanol. The solid acid modified with perfluorinated octyl shows even higher activity than liquid sulfuric acid in the transesterification reaction. The octyl group incorporated in the silica shell could also prevent the leaching of PS-SO3H during the catalytic process.