Modifications of H-ZSM-5 catalysts by NaOH treatment

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1994.1242· OSTI ID:6651197

Lietz, G; Schnabel, K H; Peuker, Ch; Gross, Th; Voelter, J ^[1]; Storek, W ^[2]

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1. Institut fuer Angewandte Chemi, Berlin (Germany)
2. Bundesanstalt fuer Materialforschung und-pruefung, Berlin (Germany)

H-ZSM-5 samples were pretreated with dilute NaOH and then transformed into the acid state. The variation of framework Al was studied by Al-MAS-NMR spectroscopy, the Al gradient by XPS and the OH groups by IR spectroscopy. The catalytic activity was studied in the conversion of propane and of methanol. The treatment of the parent zeolite (5.2 Al/u.c.) resulted in a slight decrease of the content of framework Al but in a strong enrichment of nonframework Al on the outer surface. The catalytic effect was an increased aromatization of propane and a prolonged lifetime in the methanol conversion. The treatment of a dealuminated sample, containing much nonframework Al, caused a partial reinsertion of Al into the framework. This modification leads to an enhanced aromatization of methanol. Thus treatment with NaOH can control the content of framework Al and the catalytic activity, selectivity, and stability. 25 refs., 6 figs., 1 tab.

• OSTI ID: 6651197
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 148:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

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10 SYNTHETIC FUELS
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
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ABSORPTION SPECTROSCOPY
ALCOHOLS
ALKANES
AROMATIZATION
CATALYTIC EFFECTS
CHEMICAL REACTIONS
ELECTRON SPECTROSCOPY
HYDROCARBONS
HYDROXY COMPOUNDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MAGNETIC RESONANCE
MATERIALS
METHANOL
MINERALS
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PROPANE
RESONANCE
SILICATE MINERALS
SPECTROSCOPY
X-RAY SPECTROSCOPY
ZEOLITES