Selective formation of para-xylene over H-ZSM-5 coated with polycrystalline silicalite crystals

H-ZSM-5 crystals with various Si-to-Al ratios were coated with polycrystalline silicalite-1 layers by a repeated hydrothermal synthesis. The thus-formed silicalite-1 layers were affected by the morphology of the substrate H-ZSM-5 crystals. Applied to the alkylation of toluene with methanol, the sili...

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Bibliographic Details
Published in:Journal of catalysis 2006-10, Vol.243 (2), p.389-394
Main Authors: Van Vu, Dung, Miyamoto, Manabu, Nishiyama, Norikazu, Egashira, Yasuyuki, Ueyama, Korekazu
Format: Article
Language:English
Subjects:
Alkylation
Catalysis
Catalysts
Chemistry
Crystals
Exact sciences and technology
General and physical chemistry
Hydrocarbons
Ion-exchange
Overgrowth
Silica
Silicalite-1
Surface physical chemistry
Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
Toluene
Xylene
Zeolites: preparations and properties
ZSM-5
Citations: Items that cite this one
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Description
Summary:H-ZSM-5 crystals with various Si-to-Al ratios were coated with polycrystalline silicalite-1 layers by a repeated hydrothermal synthesis. The thus-formed silicalite-1 layers were affected by the morphology of the substrate H-ZSM-5 crystals. Applied to the alkylation of toluene with methanol, the silicalite coating significantly enhanced para-selectivity up to 99.9% under all reaction conditions. The enhanced para-selectivity may originate from diffusion resistance through the inactive silicalite layer on the H-ZSM-5, resulting in increased diffusional length. The silicalite coating on the H-ZSM-5 catalysts not only improved para-selectivity, but also prevented catalyst deactivation.
ISSN:0021-9517
1090-2694
DOI:10.1016/j.jcat.2006.07.028