A comparative study of solid sulfonic acid catalysts based on various ordered mesoporous silica materials

Research output: Contribution to journalArticle

96 Citations (Scopus)

Abstract

Acid catalysts based on ordered mesoporous silica materials (MCM-41, HMS, and SBS-15) with covalently anchored propanesulfonic or benzenesulfonic acid groups were synthesized. Six samples were prepared by co-condensation of tetraethylorthosilicate with 3-mercaptopropyltrimethoxysilane or phenyltriethoxysilane in the presence of appropriate templating agents. Six other samples were made by post-synthesis modification of the parent silica materials. Syntheses were followed by oxidation or sulfonation to form surface sulfonic acid groups. Sample characterization was performed by physical (low-angle X-ray powder diffraction, nitrogen adsorption and desorption, diffuse reflectance IR, Raman, NMR, and X-ray photoelectron spectroscopies) and chemical (acid-base titration) methods. Spectroscopic techniques proved successful incorporation of the functional groups. Functionalization of the parent silicas, however, results in changes in structural characteristics (decreasing BET surface areas, changes in pore size distribution, decreasing long range orders). The samples exhibit high activities in various catalytic transformations. Catalysts with anchored benzenesulfonic acid groups of high acid strength and high acid site densities allow the selective synthesis of the cyclic dimer indan product in the dimerization of 2-phenylpropene. 2,3,5-Trimethylhydroquinone diacetate can also be produced in similar high yields in the rearrangement-aromatization of ketoisophorone. Characteristic differences in selectivities are interpreted by taking into account of differences in acid site densities, active site distribution, and the polarity of reactants and catalyst surface. The low activity and selectivity of samples made by grafting in the transformation of ketoisophorone are attributed to the non-random distribution of the acidic functions.

Original languageEnglish
Pages (from-to)46-57
Number of pages12
JournalJournal of Molecular Catalysis A: Chemical
Volume244
Issue number1-2
DOIs
Publication statusPublished - Feb 1 2006

Fingerprint

Sulfonic Acids
sulfonic acid
Silicon Dioxide
Silica
silicon dioxide
catalysts
acids
Catalysts
Acids
alpha-methylstyrol
Aromatization
Sulfonation
Dimerization
Catalyst selectivity
synthesis
selectivity
Titration
Dimers
X ray powder diffraction
Functional groups

Keywords

  • 2-Phenylpropene
  • Co-condensation
  • Grafting
  • Ketoisophorone
  • Mesoporous silicas
  • Sulfonic acid

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology
  • Materials Science (miscellaneous)

Cite this

@article{b522770e2d514a37b0990776a7ae0e7a,
title = "A comparative study of solid sulfonic acid catalysts based on various ordered mesoporous silica materials",
abstract = "Acid catalysts based on ordered mesoporous silica materials (MCM-41, HMS, and SBS-15) with covalently anchored propanesulfonic or benzenesulfonic acid groups were synthesized. Six samples were prepared by co-condensation of tetraethylorthosilicate with 3-mercaptopropyltrimethoxysilane or phenyltriethoxysilane in the presence of appropriate templating agents. Six other samples were made by post-synthesis modification of the parent silica materials. Syntheses were followed by oxidation or sulfonation to form surface sulfonic acid groups. Sample characterization was performed by physical (low-angle X-ray powder diffraction, nitrogen adsorption and desorption, diffuse reflectance IR, Raman, NMR, and X-ray photoelectron spectroscopies) and chemical (acid-base titration) methods. Spectroscopic techniques proved successful incorporation of the functional groups. Functionalization of the parent silicas, however, results in changes in structural characteristics (decreasing BET surface areas, changes in pore size distribution, decreasing long range orders). The samples exhibit high activities in various catalytic transformations. Catalysts with anchored benzenesulfonic acid groups of high acid strength and high acid site densities allow the selective synthesis of the cyclic dimer indan product in the dimerization of 2-phenylpropene. 2,3,5-Trimethylhydroquinone diacetate can also be produced in similar high yields in the rearrangement-aromatization of ketoisophorone. Characteristic differences in selectivities are interpreted by taking into account of differences in acid site densities, active site distribution, and the polarity of reactants and catalyst surface. The low activity and selectivity of samples made by grafting in the transformation of ketoisophorone are attributed to the non-random distribution of the acidic functions.",
keywords = "2-Phenylpropene, Co-condensation, Grafting, Ketoisophorone, Mesoporous silicas, Sulfonic acid",
author = "B. R{\'a}c and {\'A} Moln{\'a}r and P. Forg{\'o} and M. Mohai and I. Bert{\'o}ti",
year = "2006",
month = "2",
day = "1",
doi = "10.1016/j.molcata.2005.08.043",
language = "English",
volume = "244",
pages = "46--57",
journal = "Journal of Molecular Catalysis A: Chemical",
issn = "1381-1169",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - A comparative study of solid sulfonic acid catalysts based on various ordered mesoporous silica materials

AU - Rác, B.

AU - Molnár, Á

AU - Forgó, P.

AU - Mohai, M.

AU - Bertóti, I.

PY - 2006/2/1

Y1 - 2006/2/1

N2 - Acid catalysts based on ordered mesoporous silica materials (MCM-41, HMS, and SBS-15) with covalently anchored propanesulfonic or benzenesulfonic acid groups were synthesized. Six samples were prepared by co-condensation of tetraethylorthosilicate with 3-mercaptopropyltrimethoxysilane or phenyltriethoxysilane in the presence of appropriate templating agents. Six other samples were made by post-synthesis modification of the parent silica materials. Syntheses were followed by oxidation or sulfonation to form surface sulfonic acid groups. Sample characterization was performed by physical (low-angle X-ray powder diffraction, nitrogen adsorption and desorption, diffuse reflectance IR, Raman, NMR, and X-ray photoelectron spectroscopies) and chemical (acid-base titration) methods. Spectroscopic techniques proved successful incorporation of the functional groups. Functionalization of the parent silicas, however, results in changes in structural characteristics (decreasing BET surface areas, changes in pore size distribution, decreasing long range orders). The samples exhibit high activities in various catalytic transformations. Catalysts with anchored benzenesulfonic acid groups of high acid strength and high acid site densities allow the selective synthesis of the cyclic dimer indan product in the dimerization of 2-phenylpropene. 2,3,5-Trimethylhydroquinone diacetate can also be produced in similar high yields in the rearrangement-aromatization of ketoisophorone. Characteristic differences in selectivities are interpreted by taking into account of differences in acid site densities, active site distribution, and the polarity of reactants and catalyst surface. The low activity and selectivity of samples made by grafting in the transformation of ketoisophorone are attributed to the non-random distribution of the acidic functions.

AB - Acid catalysts based on ordered mesoporous silica materials (MCM-41, HMS, and SBS-15) with covalently anchored propanesulfonic or benzenesulfonic acid groups were synthesized. Six samples were prepared by co-condensation of tetraethylorthosilicate with 3-mercaptopropyltrimethoxysilane or phenyltriethoxysilane in the presence of appropriate templating agents. Six other samples were made by post-synthesis modification of the parent silica materials. Syntheses were followed by oxidation or sulfonation to form surface sulfonic acid groups. Sample characterization was performed by physical (low-angle X-ray powder diffraction, nitrogen adsorption and desorption, diffuse reflectance IR, Raman, NMR, and X-ray photoelectron spectroscopies) and chemical (acid-base titration) methods. Spectroscopic techniques proved successful incorporation of the functional groups. Functionalization of the parent silicas, however, results in changes in structural characteristics (decreasing BET surface areas, changes in pore size distribution, decreasing long range orders). The samples exhibit high activities in various catalytic transformations. Catalysts with anchored benzenesulfonic acid groups of high acid strength and high acid site densities allow the selective synthesis of the cyclic dimer indan product in the dimerization of 2-phenylpropene. 2,3,5-Trimethylhydroquinone diacetate can also be produced in similar high yields in the rearrangement-aromatization of ketoisophorone. Characteristic differences in selectivities are interpreted by taking into account of differences in acid site densities, active site distribution, and the polarity of reactants and catalyst surface. The low activity and selectivity of samples made by grafting in the transformation of ketoisophorone are attributed to the non-random distribution of the acidic functions.

KW - 2-Phenylpropene

KW - Co-condensation

KW - Grafting

KW - Ketoisophorone

KW - Mesoporous silicas

KW - Sulfonic acid

UR - http://www.scopus.com/inward/record.url?scp=31044440102&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=31044440102&partnerID=8YFLogxK

U2 - 10.1016/j.molcata.2005.08.043

DO - 10.1016/j.molcata.2005.08.043

M3 - Article

AN - SCOPUS:31044440102

VL - 244

SP - 46

EP - 57

JO - Journal of Molecular Catalysis A: Chemical

JF - Journal of Molecular Catalysis A: Chemical

SN - 1381-1169

IS - 1-2

ER -