Ti-PMO materials as selective catalysts for the epoxidation of cyclohexene and vernonia oil

The aim of this study is to obtain Ti-containing Periodic Mesoporous Organosilica (PMO) materials with catalytic activity in epoxidation reactions. Characterization of the PMO materials using X ray diffraction, N 2 sorption isotherms, chemical analysis (ICP-OES) and UV–vis spectroscopy reveals that the Ti-PMO materials possess ordered 2-dimensional hexagonal mesostructures, high surface areas (593–944 m 2 /g), uniform pore sizes (4.5–11 nm), large pore volumes (0.59–1.62 cm 3 /g), and tetrahedrally incorporated Ti(IV) species on the surface of the pore walls. The PMO materials with fiber-like particle morphology, which may hinder the diffusion of substrates, have been compared with those of plate-like morphology in which diffusion problems may be avoided. The catalytic activities of these materials were tested in epoxidation of cyclohexene with an optimum conversion rate of 30.5% and good epoxide selectivity (93.8%). Selected Ti-PMO materials were also effective for the epoxidation of vernonia oil, a naturally expoxidized triglyceride oil, using tert-butyl hydroperoxide as an oxidant.