Preparation, characterization and catalytic activity towards green reactions of sulfonic functionalized SBA-15

BASALDELLA, E.; LEGNOVERDE, S.; JIMENEZ MORALES,I.; RODRIGUEZ CASTELLON, E.; DALLA COSTA, B.O.; QUERINI, C.A.

ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY

SPRINGER

Lugar: Berlin; Año: 2011 vol. 17 p. 631 - 641

0929-5607

Acids 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 g nic acid s on the surface. Characterization of the samp es wa carr ed out by N2 adsorption-desorption, FTIR, XPS and acid-base titration. Spectros c te niques showed hat the effective incorporation of sulfonic groups depends on the synthesis methodology used. In turn, the SBA-15 post-synthesis funcionalization 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.