Skip to main content Accessibility help

Thermal analysis of pyridine-treated sepiolite and palygorskite

  • U. Shuali (a1), S. Yariv (a2), M. Steinberg (a2), M. Müller-Vonmoos (a3), G. Kahr (a3) and A. Rub (a3)...


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.



Hide All
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.
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.
Choudhary, V.R. (1983) Temperature-programmed desorption of organic bases on NaY zeolite under chromatographic conditions. J. Chromatography, 259, 283–290.
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.
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.
Heller, S.R. & Milne, G.W.A. (1978) EPA/NIH Mass Spectral Data Base.US Dept. Commerce, NBS, Washington.
Jakob, P., Lloyd, D.R. & Menzel, L.D. (1990) Pyridine on Ru (001): Thermal evolution. Surface Sci., 227, 325–336.
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.
Mirodatos, C., Ha, B.H., Otsuka, K. & Barthomeuf, D. (1980) Changes in mordenite acidity upon various treatments. Proc. Fifth Int. Conf. Zeolites,, 382393.
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.
Perrin, D.D., Armarego, W.L.F. & Perrin, D.R. (1966) Purification of Laboratory Chemicals., 1st edition, Pergamon Press, Oxford.
Rautureau, M. & Mifsud, A. (1977) Etude par microscope electronique des difference etats d'hydration de la sepiolite. Clay Miner., 12, 309–318.
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.
Ruiz-Hitzky, E., Casal, B. & Serratosa, J.M. (1985) Sorption of pyridine on palygorskite. Proc. 5th Meet. European Clay Groups, Prague, 125.
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.
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.
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.
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.
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.

Related content

Powered by UNSILO

Thermal analysis of pyridine-treated sepiolite and palygorskite

  • U. Shuali (a1), S. Yariv (a2), M. Steinberg (a2), M. Müller-Vonmoos (a3), G. Kahr (a3) and A. Rub (a3)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.