Dealumination of HZSM-5 zeolites. I. Calcination and hydrothermal treatment

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1996.0191· OSTI ID:476035

Campbell, S M ^[1]; Bibby, D M; Meinhold, R H ^[2]

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1. Louisana State Univ., Shreveport, LA (United States)
2. Industrial Research Ltd., Petone (New Zealand); and others

The effect of calcination and hydrothermal treatments on the structure and properties of HZSM-5 zeolites with a range of aluminum contents has been investigated. Characterization of the treated zeolites was undertaken with solid-waste NMR ({sup 27}Al and {sup 29}Si), infrared, nitrogen and water adsorption, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, chemical analysis, and {sup 129}Xe NMR spectroscopy. Both calcination and hydrothermal treatment were found to cause dealumination of the zeolite lattice and formation of extralattice aluminum species of low symmetry which remain within the pores of the zeolite. HZSM-5 with low aluminum content was found to be more resistant to dealumination by either method and the degree of dealumination was greater when steam was present in the treatment. {sup 129}Xe NMR was found to be a useful probe for the presence of extralattice aluminum in the pores of lattice dealuminated HZSM-5. 35 refs., 9 figs., 3 tabs.

• OSTI ID: 476035
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 1 Vol. 161; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
ADSORPTION
CALCINATION
CATALYSTS
CHEMICAL PREPARATION
HYDROTHERMAL SYNTHESIS
NITROGEN
NUCLEAR MAGNETIC RESONANCE
SCANNING ELECTRON MICROSCOPY
SORPTIVE PROPERTIES
WATER
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
ZEOLITES