A dimeric molecular precursor [(tBuO)2Ti mu-O2Si[OSi(OtBu)3]2]2to Ti(IV)/SiO2 catalysts for selective cyclohexene epoxidation
The new dimeric complex [(tBuO)2Ti({mu}-O2Si[OSi(OtBu)3]2)]2 (1), prepared via silanolysis of Ti(OtBu)4 with (HO)2Si[OSi(OtBu)3]2, is a structural and spectroscopic (NMR, FT-IR, UV-vis, XPS) model for Ti(IV)/SiO2. The molecular complex was used to prepare titanium-containing silica materials through both the thermolytic molecular precursor method (yielding TiO2{center_dot}3SiO2) or by grafting 1 onto mesoporous SBA-15 silica. Grafting 1 onto SBA-15 yields mostly isolated Ti(IV) sites, as evidenced by DRUV-vis and photoluminescence spectroscopies. The resulting materials were found to be active and highly selective in the epoxidation of cyclohexene, yielding up to 71% of cyclohexene oxide based on oxidant (cumene hydroperoxide) after 2 h at 65 C in toluene.
- Research Organization:
- Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE Director. Office of Science. Basic EnergySciences
- DOE Contract Number:
- AC02-05CH11231
- OSTI ID:
- 919915
- Report Number(s):
- LBNL--57111; BnR: KC0302010
- Journal Information:
- Journal of Molecular Catalysis A: Chemical, Journal Name: Journal of Molecular Catalysis A: Chemical Vol. 238; ISSN JMCCF2
- Country of Publication:
- United States
- Language:
- English
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