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Thermal analysis of pyridine-treated sepiolite and palygorskite

Published online by Cambridge University Press:  09 July 2018

U. Shuali
Affiliation:
Israel Institute for Biological Research, Ness Ziona, 70450, Israel
S. Yariv
Affiliation:
Department of Inorganic and Analytical Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
M. Steinberg
Affiliation:
Department of Inorganic and Analytical Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
M. Müller-Vonmoos
Affiliation:
Laboratory for Clay Mineralogy, Institute of Foundation Engineering and Soil Mechanics, Federal Institute of Technology, Sonneggstrasse 5, CH 8092 Zurich, Switzerland
G. Kahr
Affiliation:
Laboratory for Clay Mineralogy, Institute of Foundation Engineering and Soil Mechanics, Federal Institute of Technology, Sonneggstrasse 5, CH 8092 Zurich, Switzerland
A. Rub
Affiliation:
Laboratory for Clay Mineralogy, Institute of Foundation Engineering and Soil Mechanics, Federal Institute of Technology, Sonneggstrasse 5, CH 8092 Zurich, Switzerland

Abstract

The thermal behaviour of sepiolite and palygorskite treated with pyridine (Py) was investigated by DTA, TG, DTG and EGA (by MS) under a flow of air and inert gases (N2 or Ar). The thermal analysis showed that the organic base was adsorbed by the clays, penetrating into the clay pores and replacing zeolitic and bound water. Its presence in the pores shifted the dehydroxylation peak to temperatures higher than the corresponding peak in the untreated clays. Under N2 and Ar, thermal desorption of Py from sepiolite was observed at 260 and 650°C whereas for palygorskite only traces of Py were detected in the evolved gases. In addition to desorption, reactions of pyrolysis and condensation to coke were detected by the evolution of ammonia, methane and hydrogen, respectively. In air, oxidation of the organic matter led to the appearance of exothermic peaks. The profile of the DTA curve and the temperatures of the most intense exothermic peaks were determined by the rate of the carbon oxidation.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1991

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References

Blanco, C.J., Herrero, J., Mendioroz, S. & Pajares, J.A. (1988) Infrared studies of surface acidity and reversible folding in palygorskite. Clays Clay Miner., 36, 364–386.CrossRefGoogle Scholar
Breen, C., Deane, A.T. & Flynn, J.J. (1987) The acidity of trivalent cation-exchanged montmorillonite. Temperature-programmed desorption and infrared studies of pyridine and n-butylamine. Clay Miner., 22, 169178.CrossRefGoogle Scholar
Choudhary, V.R. (1983) Temperature-programmed desorption of organic bases on NaY zeolite under chromatographic conditions. J. Chromatography, 259, 283–290.CrossRefGoogle Scholar
Corma, A., Fornes, V. & Melo, F.V. (1987) Comparison of the information given by ammonia t.p.d. and pyridine adsorption-desorption on the acidity of dealuminated HY and LaHY zeolite cracking catalysts. Zeolites, 7, 559–563.CrossRefGoogle Scholar
Heller-Kallai, L., Miloslavski, I., Aizenshtat, Z. & Halicz, L. (1988) Chemical and mass spectrometric analysis of volatiles derived from clays. Am. Miner., 73, 376–382.Google Scholar
Heller, S.R. & Milne, G.W.A. (1978) EPA/NIH Mass Spectral Data Base.US Dept. Commerce, NBS, Washington.Google Scholar
Jakob, P., Lloyd, D.R. & Menzel, L.D. (1990) Pyridine on Ru (001): Thermal evolution. Surface Sci., 227, 325–336.CrossRefGoogle Scholar
Kojima, M., Rautenbach, M.W. & O'Connor, C.T. (1988) Acidity characterization of ion-exchanged mordenites. I. Temperature-programmed desorption of pyridine. J. Catal., 112, 495–504.Google Scholar
Mirodatos, C., Ha, B.H., Otsuka, K. & Barthomeuf, D. (1980) Changes in mordenite acidity upon various treatments. Proc. Fifth Int. Conf. Zeolites,, 382393. Google Scholar
Parker, L.M., BibbyD.M. & Meinhold, R.H. (1985) An evaluation by t.d./m.s. of the use of weak bases (ammonia, primary amines and pyridine) as probes for the study of zeolite acid sites. Zeolites, 5, 385388.CrossRefGoogle Scholar
Perrin, D.D., Armarego, W.L.F. & Perrin, D.R. (1966) Purification of Laboratory Chemicals., 1st edition, Pergamon Press, Oxford.Google Scholar
Rautureau, M. & Mifsud, A. (1977) Etude par microscope electronique des difference etats d'hydration de la sepiolite. Clay Miner., 12, 309–318.Google Scholar
Rautureau, M., Clinard, G., Mifsud, A. & Caillere, S. (1979) Etude morphologique de la palygorskite par microscope electronique. 104th Congr. Nat. Soc. Savantes, Bordeaux, Science, Sasc III. 199212.Google Scholar
Ruiz-Hitzky, E., Casal, B. & Serratosa, J.M. (1985) Sorption of pyridine on palygorskite. Proc. 5th Meet. European Clay Groups, Prague, 125.Google Scholar
Serafin, J.J. & Friend, C.M. (1989) Reactivity of pyridine on Mo (110): C-H and C-N bond activation. J.Phys. Chem., 93, 1998–2004.CrossRefGoogle Scholar
Shuau, U. Yariv, S., Steinberg, M., Müller–Vonmoos, M., Kahr, G. & Rub, A. (1988) Thermal analysis study of the adsorption of D2O by sepiolite and palygorskite. Thermochim. Acta, 135, 291–297.Google Scholar
Shuali, U., Bram, L., Steinberg, M. & Yariv, S. (1989) IR study of the thermal treatment of sepiolite and palygorskite saturated with organic amines. Thermochim. Acta, 148, 445–456.CrossRefGoogle Scholar
Shuali, U., Yariv, S., Steinberg, M., Muller-Vonmoos, M., KahrG. & Rub, A. (1990) Thermal analysis of sepiolite and palygorskite treated with butylamine. Clay Miner., 25, 107–119.CrossRefGoogle Scholar
Takahashi, M., Iwasawa, Y. & OgasawaraS. (1976) The nature of adsorbed sites on catalysts. II. Behavior of basic compounds on silica-aluminum catalysts at elevated temperatures. J. Catal., 45, 15–24.CrossRefGoogle Scholar