Highly Selective Oxidation of Styrene Over FeCl3-Imidazolium Ionic Liquid Grafted SBA-15

A composite material (FeSIL) prepared by FeCl 3 -imidazolium ionic liquid grafted on SBA-15 exhibited effective catalytic activity for solvent-free oxidation of styrene into benzaldehyde with high selectivity using H 2 O 2 oxidant and it presented easy recovery and reusability. In situ DRIFTS spectra for styrene and H 2 O 2 adsorption showed that an intermediate Fe 3+ –π surface complex on the catalyst surface was responsible for the activation of styrene and its reaction with H 2 O 2 molecules on the surface or in the bulk phase. Graphic Abstract Iron-chloride immobilized ionic liquid (FeSIL) was prepared by N -methylimidazole reacting with chloropropylsilane grafted on SBA-15 and coordinating of FeCl 3 to the imidazolium on the surface. The higher catalytic activity of the catalyst for effective oxidation of styrene under solvent-free condition were achieved The catalyst can be easily recovered and effectively reused without a significant loss in its activity.