Role of Zinc in Zn-Loaded ZSM-5 Zeolites in the Aromatization of n-Hexane

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Title:Role of Zinc in Zn-Loaded ZSM-5 Zeolites in the Aromatization of n-Hexane
Creators:
Rojasová, Edita
Smiešková, Agáta
Hudec, Pavol
Židek, Zdenek
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 64, 1, pp. 168-176
Uncontrolled Keywords:n-Hexane, Aromatization, Heterogeneous catalysis, Solid-state ion exchange, Zeolites, Acidity, ZnZSM-5

Abstract

Aromatization of n-hexane over zinc-modified ZSM-5 zeolites was investigated. It was shown that incorporation of zinc by ion exchange into cationic positions of NH<sub>4</sub>-ZSM-5 zeolite causes acid-site strength redistribution and generation of new relatively strong Lewis acid sites in zeolite increasing the selectivity of n-hexane aromatization in comparison with the parent NH<sub>4</sub>-ZSM-5 zeolite. Simultaneous presence of Lewis and Broensted acid sites in ZSM-5 zeolite does not affect the strength of Broensted acid sites in zeolite. For the activity/selectivity of aromatization of n-hexane on Zn-modified ZSM-5 zeolites, the amount of Zn and its localization in the cationic positions are decisive. The reaction of n-hexane can be also initiated by the Zn species alone in the cationic positions. ZnO species alone as an extraframework phase was found inactive in the catalyst for aromatization of n-hexane. The influence of ZnO addition on the performance of pure ammonium forms of ZSM-5 zeolites in n-hexane conversion is a result of partial migration of zinc into cationic positions of zeolite by solid-state ion exchange. <p>

Title:Role of Zinc in Zn-Loaded ZSM-5 Zeolites in the Aromatization of n-Hexane
Creators:
Rojasová, Edita
Smiešková, Agáta
Hudec, Pavol
Židek, Zdenek
Uncontrolled Keywords:n-Hexane, Aromatization, Heterogeneous catalysis, Solid-state ion exchange, Zeolites, Acidity, ZnZSM-5
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:64
Number:1
Page Range:pp. 168-176
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19990168UNSPECIFIED
ID Code:1467
Item Type:Article
Deposited On:06 Feb 2009 17:09
Last Modified:06 Feb 2009 16:09

Citation

Rojasová, Edita; Smiešková, Agáta; Hudec, Pavol; Židek, Zdenek (1999) Role of Zinc in Zn-Loaded ZSM-5 Zeolites in the Aromatization of n-Hexane. Collection of Czechoslovak Chemical Communications, 64 (1). pp. 168-176. ISSN 0010-0765

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