High activities of iron-FSM-16 materials synthesized by a microwave-hydrothermal process in friedel-crafts alkylations

Abstract

Iron-FSM-16 materials with different Si/Fe ratios (Si/Fe = 90, 60, and 10) have been synthesized by microwave-hydrothermal process and characterized by several spectroscopic techniques. X-ray diffraction, electron spin resonance, diffuse reflectance UV-visual and Mossbauer absorption spectroscopies allowed differentiation of several iron species. These species correspond to hematite particles, very small isolated Fe (III) species possibly incorporated in the mesoporous silica wall, and iron oxide clusters either isolated or agglomerated, forming “rafts” at the surface of the silica and exhibiting ferromagnetic ordering. Very importantly, catalytic data in benzylation of aromatic compounds such as benzene, toluene, and ethylbenzene with benzyl chloride shows that Fe-FSM-16 synthesized by microwave-hydrothermal process samples are very active and recycle catalysts.