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Modification of Sepiolite by Treatment with Fluorides: Structural and Textural Changes

Published online by Cambridge University Press:  28 February 2024

María Jesús Belzunce ,
Sagrario Mendioroz  and
Jerzy Haber
María Jesús Belzunce*
Affiliation:
Instituto de Catálisis y Petroleoquímica, CSIC, Campus de la UAM, Cantoblanco, 28049 Madrid, Spain
Sagrario Mendioroz
Affiliation:
Instituto de Catálisis y Petroleoquímica, CSIC, Campus de la UAM, Cantoblanco, 28049 Madrid, Spain
Jerzy Haber
Affiliation:
Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek, 30239 Kraków, Poland
*
†Present Address: Dpto de Oceanografía y Medio Ambiente Marino (AZTI), Satrústegi 8, 20008 San Sebastian, Spain.
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Abstract

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In the search for new applications of natural silicates, various F− treatments have been applied to sepiolite to increase its acidic properties and for use as a catalyst in reactions occurring via carbonium ions. Two types of treatments including hydrofluoric acid (HF) at different concentrations and 2 N NH4F have been utilized and the physicochemical characteristics of the resulting materials studied using standard techniques. The X-ray diffractogram (XRD) patterns indicate a decrease in crystallinity of the original material as well as the appearance of amorphous silica. SEM micrographs showed a shortening and aggregation of the sepiolitic fibers. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), thermogravimetric analysis/differential thermal analysis (TGA/DTA), N2 adsorption-desorption isotherms and Hg intrusion were used to study the changes occurring in the structure, surface area and pore distribution of samples and acidity was evaluated by IR and thermoprogrammed desorption (TPD) of adsorbed ammonia and pyridine. It was found that acidity increased in most of the samples after anionic and cationic interchange between the activating agents and the surface sites, or extralattice cations. Additionally, structural changes induced by treatments modified the Brönsted and Lewis acidity. Mild treatments with ammonium fluoride are more effective than HF treatments in acidity generation.

Keywords

ActivationFluoride ActivationSepioliteSilicate Acidity
Type
Research Article
Information
Clays and Clay Minerals , Volume 46 , Issue 6 , December 1998 , pp. 603 - 614
Copyright
Copyright © 1998, The Clay Minerals Society

References

Abdul-Latif, N. and Weaver, C.h.E., 1969 Kinetics of acid dissolution of palygorskite (attapulgite) and sepiolite Clays Clay Miner 17 169–178 10.1346/CCMN.1969.0170305.CrossRefGoogle Scholar
Barrett, E.P. Joyner, L.G. and Halenda, P.P., 1951 The determination of pore volume and area distributions in porous substances. I. Computation from Nitrogen isotherms J Am Chem Soc 73 373–380 10.1021/ja01145a126.CrossRefGoogle Scholar
Barthomeuf, D., 1985 Catalysis by acids and bases Amsterdam Elsevier.Google Scholar
Blanco, C. Herrero, J. Mendioroz, S. and Pajares, J.A., 1988 Infrared studies of surface acidity and reversible folding in palygorskite Clays Clay Miner 36 364–368 10.1346/CCMN.1988.0360412.CrossRefGoogle Scholar
Brückman, K. Fijał, J. Haber, J. Kłapyta, Z. Wiltowski, T. and Żabiński, W., 1976 Influence of different activation methods on the catalytic properties of montmorillonite Mineralogia Polonica 7 5–12.Google Scholar
Campelo, J.M. García, A. Luna, D. and Marinas, J.M., 1989 Textural properties, surface chemistry and catalytic activity in cy-clohexene skeletal isomerization of acid treated natural sepiolites Mater Chem Phys 24 51–70 10.1016/0254-0584(89)90045-X.CrossRefGoogle Scholar
Corina, A. Fornés, V. and Ortega, E., 1985 The nature of acid sites on fluorinated γ-alumina J Catal 92 284–295 10.1016/0021-9517(85)90262-3.CrossRefGoogle Scholar
Corma, A. Mifsud, A. and Pérez-Pariente, J., 1986 Etude de l’attaque acide de la sepiolite: Modification des propriétés texturales Clay Miner 21 69–84 10.1180/claymin.1986.021.1.06.CrossRefGoogle Scholar
Corma, A. and Pérez-Pariente, J., 1987 Catalytic activity of modified silicates: 1. Dehydration of ethanol catalyzed by acidic sepiolite Clay Miner 22 423–433 10.1180/claymin.1987.022.4.06.CrossRefGoogle Scholar
Dandy, A.J. and Nadiye-Tabbiruka, M.S., 1982 Surface properties of sepiolite and its catalytic activity for ethanol decomposition Clays Clay Miner 30 347–352 10.1346/CCMN.1982.0300505.CrossRefGoogle Scholar
Farmer, V.C. and Mortland, M.M., 1966 An infrared study of the coordination of pyridine and water to exchangeable cations in montmorillonite and saponite J Chem Soc (A) 344–351.CrossRefGoogle Scholar
Fernández Alvarez, T., 1972 Activación de la sepiolita conácido clorhídrico Bol Soc Esp Cerám Vidr 11 6.Google Scholar
Fijał, J. Żyła, H. and Tokarz, M., 1985 Chemical, sorptive and morphological properties of montmorillonite treated with ammonium bifluoride (NH4HF2) Clay Miner 20 81–92 10.1180/claymin.1985.020.1.07.CrossRefGoogle Scholar
Folgado, M.A., 1983 Caracterización textural y estructural de una sepiolita natural y activada. [Ms.Sc. thesis] Madrid, Spain Univ Complutense de Madrid.Google Scholar
Fripiat, J.J., 1988 High resolution solid state NMR study of pillared clays Catal Today 2 281–295 10.1016/0920-5861(88)85010-7.CrossRefGoogle Scholar
Gerberich, H. Lutinskì, F.L. and Hall, W.K., 1966 Studies of the hydrogen held by solids. X. Fluorided aluminas as acid catalysts J Catal 6 209 10.1016/0021-9517(66)90051-0.CrossRefGoogle Scholar
González, L. Ibarra, L.M. Rodríguez, A. Moya, J.S. and Valle, F.J., 1984 Fibrous silica gel obtained from sepiolite by HCl attack Clay Miner 19 93–98 10.1180/claymin.1984.019.1.10.CrossRefGoogle Scholar
González, F. Pesquera, C. Blanco, C. Benito, I. Mendioroz, S. and Pajares, J.A., 1989 Structural and textural evolution of Aland Mg- Palygorskites. I Under acid treatment Appl Clay Sci 4 373–388 10.1016/0169-1317(89)90043-4.CrossRefGoogle Scholar
López-González, J.D. Ramírez-Sáenz, A. Rodríguez-Reinoso, F. Valenzuela-Calahorra, C. and Zurita Herrera, L., 1981 Activación de una sepiolita con disoluciones diluádas de HNO3 y posteriores tratamientos térmicos. I. Estudio de la superficie especffica Clay Miner 16 103–113 10.1180/claymin.1981.016.1.08.CrossRefGoogle Scholar
Matulewicz, E.R.A. Kerkhof FR Moulijn, J.A. and Reìstma, H.J., 1980 Structure and activity of fluorinated alumina. I. Determination of the number of protonic sites by an IR study of adsorbed pyridine J Colloid Interface Sci 77 110–120 10.1016/0021-9797(80)90421-X.CrossRefGoogle Scholar
Mendioroz, S. Pajares, J.A. Benito, I. Pesquera, C. Gonzalez, F. and Blanco, C., 1987 Texture evolution of montmorillonite under progressive acid treatment. Change from H3 to H2 Type of Hysteresis Langmuir 3 676–681 10.1021/la00077a017.CrossRefGoogle Scholar
Nagata, H. Shimoda, S. and Toshio, S., 1974 On dehydration of bound water of sepiolite Clays Clay Miner 22 285–293 10.1346/CCMN.1974.0220310.CrossRefGoogle Scholar
O’Reily, D.E., 1966 Sbornik “Kataliz” Moscow Moscow Ed. Mir.Google Scholar
Preisinger, A., 1963 Sepiolite and related compounds: Its stability and application Clays Clay Miner 10 365–371 10.1346/CCMN.1961.0100132.CrossRefGoogle Scholar
Prost, R., 1976 Spectre infrarouge de l’eau présente dans l’attapulgite et la sepiolite Bull Grpe Fr Argiles 25 53–56 10.3406/argil.1973.1178.CrossRefGoogle Scholar
Rey-Bueno, F. Villafranca-Sanchez, M. González-Pradas, E. and López-González, J.D., 1985 Adsorción de amoniaco, meti-lamina y etilamina sobre una sepiolita An Quim 81B 18–21.Google Scholar
Rich, A.D., 1960 Industrial minerals and rocks 3rd New York AIME.Google Scholar
Ruíz-Hitzky, E. and Casal, B., 1985 Epoxide rearrangements on mineral and silica-alumina surfaces J Catal 92 291–295 10.1016/0021-9517(85)90263-5.CrossRefGoogle Scholar
Serna, C. Van Scoyoc, G.E., Mortland, M.M. and Farmer, V.C., 1978 Infrared study of sepiolite and palygorskite surface Proc Int Clay Conf Oxford, UK. Amsterdam Elsevier 99–109.Google Scholar
Serna, C. Van Scoyoc, G.E. and Ahlrichs, J.L., 1976 Uncoupled water found in palygorskite J Chem Phys 65 3389–3390 10.1063/1.433477.CrossRefGoogle Scholar
Serratosa, J.M., Mortland, M.M. and Farmer, V.C., 1979 Surface properties of fibrous clay minerals (palygorskite and sepiolite) Proc Int Clay Conf; 1978; Oxford, UK Amsterdam Elsevier 99–109.Google Scholar
Sing, K.S.W. Everett, D.H. Haul, R.A.W. Moscou, L. Pierotti, R.A. Rouquero, I.J. and Siemieniewska, T., 1985 Reporting physisorption data for gas/solid systems with special reference to determination of surface area and porosity Pure Appi Chem 58 603–919 10.1351/pac198557040603.CrossRefGoogle Scholar
Theng, B.K.G., 1974 The chemistry of clay-organic reactions London London Hilger.Google Scholar
Urabe, K. Sakurai, H. and Izami, Y., 1988 Cation-exchanged synthetic saponite as a “heat-stable” acidic clay catalyst J Chem Soc Chem Commun 1520.CrossRefGoogle Scholar
Villafranca-Sánchez, M. Valverde-García, A. González-Pradas, E. and Rey-Bueno, F., 1987 Estudio del proceso de retención de anilina por una sepiolita An Quim 83B 151–156.Google Scholar
Washburn, E.W., 1921 Note on a method of determining the distribution of pore sizes in a porous material Proc Natl Acad Sci USA 7 115–120 10.1073/pnas.7.4.115.CrossRefGoogle Scholar