Abstract
With regard to H-Y type zeolites dealuminated by hydrothermal and acid treatments, their physical properties were characterized by measurements of 29Si- and 27Al-MAS-NMR, IR, and X-ray diffraction. The secondary pores were quantitatively analyzed by the t-plot method for nitrogen adsorption isotherm at liquid nitrogen temperature and were then compared with the results of samples dealuminated by SiCl4 treatment.
The plateau region of the nitrogen adsorption isotherm diminished as hydrothermal and acid treatments proceeded, with the result that the shape of the t-plot changed to that of three straight sections. This t-plot shape suggested that the secondary pores with relatively consistent sizes could develop with the progress of the treatment. On the other hand, SiCl4 treatment was found to produce less secondary pores than hydrothermal and acid treatments. The surface area of micropores calculated from the t-plots gave a considerably higher value than values obtained from the BET equation and from that calculated geometrically. This is attributable to the micropore filling effect.
Similar content being viewed by others
References
Beyer, Hermann K. and I. Belenykaja, “A New Method for the Dealumination of Faujasite-type Zeolites,” Catalysis by Zeolites, B. Imelik et al. (Eds.), p. 203, Elsevier, Amsterdam, 1980.
Brunauer, S., L.S., W.E. Deming, and E. Teller, “On a Theory of the van der Waals Adsorption of Gases,” J. Amer. Chem. Soc., 62, 1723-1732 (1940).
Grobet, P.J., H. Geerts, M. Tielen, J.A. Martens, and P.A. Jacobs, “Framework and Non-Framework Al Species in Dealuminated Zeolite Y,” Stud. in Surface Sci. and Catal., 46, 721-734 (1989).
Horikoshi, H., S. Kasahara, T. Fukushima, K. Itabashi, T. Okada, O. Terasaki, and D. Watanabe, “Study of Mesopores Induced by Dealumination in Zeolite Y,” Nippon Kagaku Kaishi, 398-404 (1989).
Kawai, T. and K. Tsutsumi, “Evaluation of Hydrophilic-Hydrophobic Character of Zeolites by Measurements of their Immersional Heats in Water,” Colloid and Polymer Science, 270, 711-715 (1992).
Kawai, T., T. Yanagihara, and K. Tsutsumi, “Adsorption Characteristics of Chloroform on Modified Zeolites from Gaseous Phase as well as its Aqueous Solution,” Colloid and Polymer Science, 272, 1620-1626 (1994).
Lohse, U. and M. Mildebrath, “Dealuminated Y-type Molecular Sieves. Porosity of Dealuminated Molecular Sieves,” Z. Anorg. Allg. Chem., 476, 126-135 (1981).
Lohse, U., H. Stach, H. Thamm, W. Schirmer, A. Isirikjan, N. Regent, and M. Dubinin, “Dealuminated Molecular Sieves of Y type. Determination of Micro and Secondary Pore Volumes by adsorption measurements,” Z. Anorg. Allg. Chem., 460, 179-190 (1980).
Lynch, J., F. Raatz, and P. Dufresne, “Characterization of the Textural Properties of Dealuminated HY Forms,” Zeolites, 7, 333-340 (1987).
Maher, P.K., F.D. Hunter, and J. Scherzer, “Crystal Structures of Ultrastable Faujasites,” Adv. Chem. Ser., 101, 266-278 (1971).
Scherzer, J., “The Preparation and Characterization of Aluminum-Deficient Zeolites,” ACS Symp. Ser., 248, 157-200 (1986).
Sohn, Jong R., S.J. DeCanio, and Jack H. Lunsford, “Determination of Framework Aluminium Content in Dealuminated Y-type Zeolites: A Comparison Based on Unit Cell Size and Wavenumber of I.R. Bands,” Zeolites, 6, 225-227 (1986).
Zukal, A., V. Patzelova, and U. Lohse, “Secondary Porous Structure of Dealuminated Y Zeolites,” Zeolites, 6, 133-136 (1986).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kawai, T., Tsutsumi, K. Evaluation of the Secondary Pore Structure of Hydrothermally- and Acid-treated Faujasite Type Zeolites. Adsorption 4, 225–231 (1998). https://doi.org/10.1023/A:1008825531341
Issue Date:
DOI: https://doi.org/10.1023/A:1008825531341