| Autor: |
Basaldella, Elena I., Legnoverde, M. Soledad, Jiménez-Morales, Ignacio, Rodríguez-Castellón, Enrique, Dalla Costa, Bruno O., Querini, Carlos A. |
| Zdroj: |
Adsorption; Jun2011, Vol. 17 Issue 3, p631-641, 11p, 1 Diagram, 3 Charts, 10 Graphs |
| Abstrakt: |
idic heterogeneous catalysts based on the anchorage of sulfonic groups on SBA-15 mesoporous silica were synthesized. In a first synthesis step, samples containing mercapto groups were prepared by co-condensation of tetraethylorthosilicate with 3-mercaptopropyltrimethoxysilane, in presence of ethylene-propylene block copolymer as mesoporous silica structure director. In other samples, mercapto groups were introduced by post-functionalization of the traditional calcined SBA-15. In a second step, these mercapto groups were oxidized in order to get sulfonic acid groups on the surface. Characterization of the samples was carried out by N adsorption-desorption, FTIR, XPS and acid-base titration. Spectroscopic techniques showed that the effective incorporation of sulfonic groups depends on the synthesis methodology used. In turn, the SBA-15 post-synthesis functionalization produces changes in structural characteristics like a decrease in BET surface and changes in the pore size distribution. The as-prepared materials were tested as acid catalysts in the alkylation of isobutane with 1-butene, and in the esterification of free fatty acids with methanol. The results obtained show a lack of activity in the alkylation reaction which can be associated with the formation and stabilization of the intermediate carbocation species. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
Full text from SpringerLink