Design and tailoring of a novel heterogeneous catalyst for epoxidation of 1-octene

Abstract

A series of alkylsilylated fluorinated zirconia and zeolite containing titanium were prepared by titanium impregnation followed by fluorination and alkylsilylation of zirconium oxide and NaY zeolite. These samples were characterized by 13C and 29Si magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), x-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-VIS), hydrophobicity measurement, Brunner, Emmet and Teller (BET) surface area analysis and energy dispersive x-ray analysis (EDAX). The materials have been designed for epoxidation of 1-octene with aqueous hydrogen peroxide as oxidant. Epoxidation of alkenes is one of the most important methods of functionalizing simple hydrocarbons. Analysis by gas chromatography-mass spectrometry (GC-MS) indicates that 1,2-epoxyoctane is the sole product of the reaction with 100% selectivity. The alkylsilylated fluorinated catalysts were more active and more efficient than the conventional titania-silica and zirconia-silica mixed oxides in linear alkene epoxidation; enhanced by the presence of alkylsilane and fluorine groups in the catalysts. Modification with alkylsilane was aimed to induce the hydrophobic behaviour of zirconia and zeolite which are hydrophilic in nature; whereas fluorine was chosen for its electron-drawing effect which further activates the titanium active sites.