A novel route for preparation of Ti-containing mesoporous silica with high catalytic performance by using a molecular precursor tetrakis(tris-tert- butoxysiloxy)titanium

Mesoporous silica containing isolated Ti with variable Si/Ti ratios was prepared by pyrolysis of a mixture of tetrakis(tris-tert-butoxysiloxy)titanium (TS4) and tetraethoxysilane (TEOS) through a hard template method. TEOS plays two roles as a silica source and solvent. TS4 works as a catalyst for the hydrolysis of TEOS. Titanium species are found to be isolated in the silica frameworks, supported by DR-UV-vis, FT-IR, ESR, and XPS. The mesoporous structure was verified by XRD, N₂ adsorption, and SEM. The results of the catalytic performance for the oxidation reaction of cyclohexene using tert-butoxy hydrogen peroxide (TBHP) as oxidant show that high conversion (29%) of cyclohexene and selectivity (98%) of cyclohexene oxide are realized for the Ti-containing mesoporous silica with Si/Ti ratios of 28 and 51.