Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-26T05:27:16.599Z Has data issue: false hasContentIssue false
  • English
  • Français

Properties and Catalytic Activity of Acid-Modified Montmorillonite and Vermiculite

Published online by Cambridge University Press:  28 February 2024

J. Ravichandran  and
B. Sivasankar
J. Ravichandran
Affiliation:
Department of Chemical Engineering, Anna University, Madras - 600 025, India
B. Sivasankar
Affiliation:
Department of Chemistry, Anna University, Madras - 600 025, India
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The acidic properties of acid-modified montmorillonite and vermiculite were determined by pyridine and ammonia adsorption to correlate with the alkylating and dehydrating activity of the activated samples. Treatment of the minerals with different concentrations of hydrochloric acid results in the variation of overall acidity and density of acidic sites. Infrared (IR) spectral and differential scanning calorimetric analyses have revealed the presence of Bronsted and Lewis acid sites on the activated samples. The catalytic activity towards the above reaction has been correlated to the acid strength and density of Lewis acid sites. Treatment of montmorillonite with hydrochloric acid in the range of 0.1 and 0.3 M and vermiculite with 0.2 to 0.3 M seemed to be suitable for the conversion of methanol into olefin-rich hydrocarbons. Acid-activated montmorillonite catalyzed the isopropylation of benzene to a maximum extent of 16%, whereas acid-activated vermiculite gave a maximum conversion of only 4%.

Keywords

AcidityBenzeneCatalyst CharacterizationHydrocarbonsIsopropylationMethanol DehydrationMontmorilloniteVermiculite
Type
Research Article
Information
Clays and Clay Minerals , Volume 45 , Issue 6 , December 1997 , pp. 854 - 858
Copyright
Copyright © 1997, The Clay Minerals Society

References

Aboul Gheit, A.K., 1988 Desorption of presorbed ammonia, trimethylamine and pyridine from the acid sites or mordenites via differential scanning calorimetry Thermochim Acta 132 257–264 10.1016/0040-6031(88)87117-X.CrossRefGoogle Scholar
Burch, R. and Warburton, C.I., 1986 Zirconium containing pillared interlayer clays II. Catalytic activity for the conversion of methanol into hydrocarbon J Catal 97 511–515 10.1016/0021-9517(86)90022-9.CrossRefGoogle Scholar
Ebeid, F.M. Ali, L.I. Amin, N.H. and Abd-Alla, F.F., 1992 Conversion of methanol metal salts of 12-molybdo phosphoric acid Indian J Chem 31 921–928.Google Scholar
Farmer, V.C., 1974 The layer silicates. Infrared of minerals London Mineral Soc 343–349 10.1180/mono-4.CrossRefGoogle Scholar
Hair, M.L., 1967 Infrared spectroscopy in surface chemistry New York Marcel Dekker.Google Scholar
Occelli, M.L., 1983 Catalytic cracking with an interlayered clay. A two dimensional molecular sieve Ind Eng Chem Prod Res Dev 22 553–559 10.1021/i300012a008.CrossRefGoogle Scholar
Occelli, M.L. Innes, R.A. Hwu, F.S.S. and Hightower, J.W., 1985 Sorption and catalysis on sodium montmorillonite interlayered with aluminum oxide clusters Appl Catal 14 69–82 10.1016/S0166-9834(00)84345-6.CrossRefGoogle Scholar
Pinnavaia, T.J., 1983 Intercalated clay catalysts Science 220 365–371 10.1126/science.220.4595.365.CrossRefGoogle ScholarPubMed
Ravichandran, J. and Sivasankar, B., 1995 Characterisation of acid activated montmorillonite and vermiculite clays by thermal desorption and differential scanning calorimetric techniques Indian J Chem 34A 127–130.Google Scholar
Suquet, H. Chevalier, S. Marcilly, C. and Barthomeuf, D., 1991 Preparation of porous materials by chemical activation of the Llano vermiculite Clay Miner 26 49–60 10.1180/claymin.1991.026.1.06.CrossRefGoogle Scholar
Theocharis, C.R. Jacob, K.J. and Gray, A.C., 1988 Enhancement of Lewis acidity in layer aluminosilicates J Chem Soc, Faraday Trans 84 1509–1516 10.1039/f19888401509.CrossRefGoogle Scholar