Abstract
An active and stable mesoporous titanosilica, denoted as Ti-TUD-1, has been synthesized using a cheap, small and multifunctional chemical, triethanolamine (TEA), instead of surfactants. TEA not only is applied as a mesopore template and as director of positioning Ti-sites onto the internal mesopore surface via the formation of titanium-TEA complexes, but also stabilizes titanium sources, which ensures the possibility of forming isolated tetrahedrally coordinated Ti-sites. Ti-sites. Ti-TUD-1 features three-dimensionally randomly connected mesopores with walls of about 2.5-4 nm in thickness. Its surface area can reach about 700-1000 m2/g and its pore sizes are tunable. After calcination at 1000°C and boiling in water, it kept a high integrity, a high surface area and only a slight change in pore sizes occured. UV-VIS spectra revealed that tetrahedrally co-ordinated Ti-sites are quite stable under thermal and hydrothermal treatments. It also showed about 5.6 times higher activity for cyclohexene epoxidation than the framework-substituted Ti-MCM-41 and similar activity compared to Ti-grafted MCM-41.
Lingua originale | Inglese |
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pagine (da-a) | 181-187 |
Numero di pagine | 7 |
Rivista | Microporous and Mesoporous Materials |
Volume | 48 |
Numero di pubblicazione | 1-3 |
DOI | |
Stato di pubblicazione | Pubblicato - nov 2001 |