Siliceous extra-framework species in dealuminated Y zeolites generated by steaming

verfasst von: W. Lutz, H. Toufar, D. Heidemann, N. Salman, C. H. Rüscher, T. M. Gesing, J. Chr Buhl, R. Bertram
Abstract: The dealumination of NH₄Y zeolite by steaming at 873 K and 1 bar water pressure is accompanied by a partial decomposition of the framework. X-ray amorphous aluminosilicate and silica gel are formed as extra-framework siliceous species in addition to the known polymeric aluminium ions. Source of the aluminosilicate and silica gel are Al-rich and Si-rich parts of the non-homogeneously crystallized FAU framework which are unstable during steaming. The Al-rich part consists of a Si/Al gradient as characterized by means of Molybdate experiments. The extra-framework siliceous species are identified by ²⁹Si MAS NMR spectroscopic measurements as extra Si(4Al) and Si(0Al) signals which appear separated from the corresponding signal distribution of the zeolite framework. A certain portion of this silica gel superimposes, however, the Si(0Al) and Si(1Al) signal distribution of the zeolite framework. This "non-visible" part is quantified by the calculation of Si/Al ratio obtained by ²⁹Si MAS NMR spectroscopy with respect to results obtained using the characteristic lattice parameter values.
Organisationseinheit(en): Institut für Mineralogie
Externe Organisation(en): Tricat Zeolites GmbH
Humboldt-Universität zu Berlin (HU Berlin)
Leibniz-Institut für Kristallzüchtung (IKZ)
Typ: Artikel
Journal: Microporous and Mesoporous Materials
Band: 104
Seiten: 171-178
Anzahl der Seiten: 8
ISSN: 1387-1811
Publikationsdatum: 23.08.2007
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Allgemeine Chemie, Allgemeine Materialwissenschaften, Physik der kondensierten Materie, Werkstoffmechanik
Elektronische Version(en): https://doi.org/10.1016/j.micromeso.2007.01.028 (Zugang: Geschlossen)

BibTeX

@article{be502c97720e47e89a94d2b04e71c8c6,
title = "Siliceous extra-framework species in dealuminated Y zeolites generated by steaming",
abstract = "The dealumination of NH4Y zeolite by steaming at 873 K and 1 bar water pressure is accompanied by a partial decomposition of the framework. X-ray amorphous aluminosilicate and silica gel are formed as extra-framework siliceous species in addition to the known polymeric aluminium ions. Source of the aluminosilicate and silica gel are Al-rich and Si-rich parts of the non-homogeneously crystallized FAU framework which are unstable during steaming. The Al-rich part consists of a Si/Al gradient as characterized by means of Molybdate experiments. The extra-framework siliceous species are identified by 29Si MAS NMR spectroscopic measurements as extra Si(4Al) and Si(0Al) signals which appear separated from the corresponding signal distribution of the zeolite framework. A certain portion of this silica gel superimposes, however, the Si(0Al) and Si(1Al) signal distribution of the zeolite framework. This {"}non-visible{"} part is quantified by the calculation of Si/Al ratio obtained by 29Si MAS NMR spectroscopy with respect to results obtained using the characteristic lattice parameter values.",
keywords = "Dealumination, Siliceous extra-framework species, Steaming, Zeolites",
author = "W. Lutz and H. Toufar and D. Heidemann and N. Salman and R{\"u}scher, {C. H.} and Gesing, {T. M.} and Buhl, {J. Chr} and R. Bertram",
year = "2007",
month = aug,
day = "23",
doi = "10.1016/j.micromeso.2007.01.028",
language = "English",
volume = "104",
pages = "171--178",
journal = "Microporous and Mesoporous Materials",
issn = "1387-1811",
publisher = "Elsevier BV",
number = "1-3",
}