Facile Synthesis of Fe-Loaded Mesoporous Silica by a Combined Detemplation-Incorporation Process through Fenton's Chemistry

The present work describes a new approach to synthesize Fe species within the channels of mesoporous SBA-15 silica using Fenton's reagent (Fe2+-H2O2) as an iron precursor. For the first time Fe ions were incorporated within as-synthesized surfactant-containing mesoporous host by a simultaneous detemplation and Fe-incorporation process at low temperature. The resulting materials were characterized by X-ray diffraction (XRD), thermogravimetric differential thermal analysis, N-2 sorption, DRIFTS, transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy, UV Raman, X-ray photoelectron spectroscopy, and Friedel-Crafts alkylation catalysis. The ordered mesostructure of the SBA-15 host is retained as indicated by XRD and HRTEM, and the surface areas of the Fe-SBA-15 materials are in the range of 640-853 m(2) g(-1) comparable to 784 m(2) g(-1) for the calcined host. The characterization results also indicate the presence of iron species inside the silica pores, as well as a good dispersion of the iron oxide nanoclusters within the pores of the host material. Controlled iron loading was possible to a maximum of 9 wt %. The catalyst shows significantly enhanced performance on benzylation of benzene using benzyl chloride as the alkylating agent compared to conventionally prepared Fe/SBA-15.