Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10245106 | Journal of Catalysis | 2005 | 10 Pages |
Abstract
The new complex (iPrO)2Ta[OSi(OâtBu)3]3 (1) was prepared via silanolysis of Ta(OâiPr)5 with (tBuO)3SiOH and is a useful structural and spectroscopic (NMR, FTIR) model of Ta(V) on silica. The complex was also used to prepare tantalum-containing silica materials, via the thermolytic molecular precursor method (yielding Ta2O5Â â
 6SiO2 and Ta2O5 â
 18SiO2) or by grafting 1 onto mesoporous SBA-15 silica (yielding a surface-supported tantala species, TaSBA-15). The solution phase thermolysis of 1 in nonpolar media afforded homogeneous, high-surface-area (ca. 450 m2âgâ1) xerogels (Ta2O5 â
 6SiO2) that are amorphous up to approximately 1100â°C. A more silica-rich tantala-silica material (Ta2O5 â
 18SiO2) was prepared via a solution-phase co-thermolytic route with 1 and HOSi(OâtBu)3, to yield a material with a Si/Ta ratio of 9/1. It was demonstrated that tantala-silica materials are active as catalysts for cyclohexene oxidation.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Catalysis
Authors
Richard L. Brutchey, Claus G. Lugmair, Lars O. Schebaum, T. Don Tilley,