Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Valverde, J.L. Articles by Molina, C.B. Search for Related Content GeoRef GeoRef Citation

ENHANCED THERMAL STABILITY OF Al-PILLARED SMECTITES MODIFIED WITH Ce AND La

Chemical Engineering Department, Faculty of Chemistry, University of Castilla-La Mancha, Campus Universitario s/n. 13004, Ciudad Real, Spain
¹ Chemical Department, Faculty of Science and Engineering, Pontificia University Catholic of Peru, Av. Universitaria, Cuadra 18, San Miguel, Lima 100, Perú

E-mail of corresponding author: jlvalver{at}inqu-cr.uclm.es

A commercial bentonite (primarily smectite) from Fischer Scientific Company (F bentonite) and a natural bentonite from Peru (P bentonite) were used in the preparation of pillared clays with polyoxymetal cations of Al that were subsequently modified with Ce and La. Several Al/metal ratios (5 and 9) were used to investigate the effects on the thermal and hydrothermal stability of these synthetic clays. The structure of these materials was studied by X-ray diffraction. Isotherms were determined by N₂ adsorption. Thermal stability was determined using thermogravimetric (TG) measurements and ammonia-TPD (temperature programmed desorption) was used to obtain acidity data. These materials exhibited basal spacings from 16 to 20 Å, with surface areas from 239 to 347 m² g^–1, with microporosity contributing from 50 to 80% of the total surface area. Pillared clays prepared from F bentonite generally showed larger basal spacings and surface areas than those prepared from P bentonite. Pillared clays modified with Ce or La did not show any apparent structural changes relative to the Al-pillared clays. Pillared clays modified with Ce and La had similar acid properties as Al-pillared clays. In contrast, the thermal and hydrothermal stabilities of these materials were greater than Al-pillared clays. However, Ce-pillared clay appears to be more effective than La-pillared clay in delaying the dehydroxylation of pillared clays with increasing temperature. The intercalation of Ce and La into Al-pillared clays improved the thermal stability, which may increase the utility of these materials as catalysts.

Key Words: Bentonite • Ce • La • Pillared Clays

This article has been cited by other articles:

				J. T. Kloprogge, J. T. Kloprogge, J.A. R. van Veen, E. Booij, and R. L. Frost COMMENTS ON "ENHANCED THERMAL STABILITY OF Al-PILLARED SMECTITES MODIFIED WITH Ce AND La" BY J.L. VALVERDE, P. CANIZARES, M.R. SUN KOU, AND C.B. MOLINA Clays and Clay Minerals, April 1, 2001; 49(2): 183 - 185. [Full Text] [PDF]

				J.L. Valverde, P. Canizares, M.R. S. Kou, and C.B. Molina REPLY TO THE COMMENT BY J.T. KLOPROGGE, J.A. ROB VAN VEEN, E. BOOIJ, AND RAY L. FROST ON "ENHANCED THERMAL STABILITY OF Al-PILLARED SMECTITES MODIFIED WITH Ce AND La" Clays and Clay Minerals, April 1, 2001; 49(2): 186 - 187. [Full Text] [PDF]