Catalysis Letters, Vol.94, No.3-4, 187-191, 2004
Synthesis of Ti containing molecular sieves using a diethoxysiloxane-ethyltitanate polymer
Ti-MCM-41 and SiO2-TiO2-xerogel were prepared using a double alkoxide precursor, diethoxysiloxane-ethyltitanate (DESET, 93.75 mol Si : 6.25 mol Ti). Characterization of the materials prepared was carried out using XRD, N-2 and water adsorption isotherm, SEM/EDS, TEM analysis, UV - Vis and FT-IR spectroscopies. Catalytic activity was measured for cyclohexene epoxidation using H2O2 as an oxidant. High titanium amounts in tetrahedral coordination in DESET resulted in Ti-MCM-41 with high catalytic activity accompanied by enhanced H2O2 selectivity. It was also possible to prepare TS-1 with MFI structure using DESET as a precursor, but titanium species in the sample were highly unstable and mostly came out from the framework to form large TiO2 clusters upon calcination.