POSS-derived solid acid catalysts with excellent hydrophobicity for highly efficient transformations of glycerol

Abstract

Novel excellent hydrophobic POSS-derived solid acid catalysts were successfully synthesized through free radical copolymerization of polyhedral oligomeric vinylsilsesquioxanes (POSS) with sodium p-styrene sulfonate (POSS-x-SO₃H), and characterized by several physicochemical methods. Green routes toward valorization of glycerol via acetalization with benzaldehyde and esterification of glycerol with acetic acid have been proposed. The as-prepared catalysts showed very high activities and selectivities toward glycerol derivatives within a short reaction time, which were even higher than that of homogeneous H₂SO₄. The POSS-2-SO₃H catalyst was recycled up to five times without any significant loss of activity. The excellent performance of these solid acid catalysts is mostly attributed to the combination of superior hydrophobicity and large specific surface area.