synthesis of fine chemicals by using solid base catalysts
| Autor: | Jui- I Yu, 余瑞益 |
|---|---|
| Rok vydání: | 1999 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 87 Three types of solid base catalysts are utlized: (1) the mesoporous molecular sieve Al-MCM-41 impregnated with magnesium oxide and calcium oxide, respectively; (2) Alkaline earth metal oxides: MgO, CaO, SrO and BaO; (3) hydrotalcites. The catalysts were characterized with various techniques of XRD, SEM, ICP-AES, 27Al and 29Si MAS-NMR, FTIR, TPD of carbon dioxide and gas adsorption analyzer. Impregnation of Al-MCM-41 with magnesium oxide and calcium oxide results in the decrease of surface area, pore volume and the expelling of aluminum from the Al-MCM-41 framework with concomitant increase of the amount of basic sites. For alkaline earth metal oxides, the amount of basic sites and the surface area decrease in the order of MgO > CaO > SrO > BaO whereas the basic strength exhibits the reverse trend. Increasing Mg/Al ratio of hydrotalcites results in an increase of base amount and a decrease of surface area. α-amyl-cinnamaldehyde was synthesized from benzaldehyde and heptaldehyde by using MgO/Al-MCM-41、CaO/Al-MCM-41、alkaline earth metal oxide and hydrotalcites in a batch autoclave reactor. The effects of reaction temperature、pressure、benzaldehyde/ heptaldehyde molar ratio and different aldehydes are studied. The conversion of heptaldehyde increases with increasing reaction temperature, reaction time and the carbon number of aldehydes, but slightly decreases with an increase of pressure; it also depends on the nature of catalysts. α-amyl-cinnamaldehyde is formed favorably at lower reaction temperature and high benzaldehyde/ heptaldehyde molar ratio by using catalysts of weaker basicity. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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