Transalkylation of toluene with cumene over zeolites Y dealuminated in solid-state

Part II. Effect of the introduced Lewis acid sites

V. Mavrodinova, M. Popova, R. M. Mihályi, Borbély G. Páł, Ch Minchev

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The effects of the introduced Lewis acid sites of different kind (InO+ or AlO+) and the variation of InO+ concentration on the catalytic behavior of dealuminated in solid-state HY zeolites in the reaction of cumene-toluene transalkylation have been studied. The catalysts, indium modified HY(3.7) and ultra stable zeolite USY(3.4), containing essentially equivalent amounts of framework aluminum and Lewis acid sites (InO+ and AlO+, respectively), have been compared to the initial HY(3.7), not containing any extra-framework aluminum (EFAl). Strictly controlled conditions were used for the formation of Lewis acid sites: through reductive solid-state ion exchange (RSSIE) for InO+ or by steaming in the case of AlO+. The ratio between the Lewis and Broensted acid sites was varied by progressive replacement of the protons by InO+ cations in HY(5.6) zeolite. The zeolites modified by monovalent (InO+ and AlO+) have, as a result, an enhanced catalytic activity in comparison with HY(3.7). This effect is mainly due to intense side reactions of dealkylation, oligomerization, cracking and re-alkylation at the expense of the cymenes formation. The data for the distribution of the reaction products suggest a highly preferred mechanism of dealkylation/alkylation with the increase of the Lewis/Broensted acid site ratio. The presence of cation-connected Lewis acid sites is supposed to be responsible for the fast samples' deactivation.

Original languageEnglish
Pages (from-to)197-209
Number of pages13
JournalApplied Catalysis A: General
Volume248
Issue number1-2
DOIs
Publication statusPublished - Aug 8 2003

Fingerprint

Zeolites
Lewis Acids
Toluene
Acids
Alkylation
Aluminum
Cations
Positive ions
Oligomerization
Indium
Reaction products
cumene
Protons
Catalyst activity
Ion exchange
Catalysts

Keywords

  • Cumene-toluene
  • Dealuminated Y
  • In-modified Y
  • Lewis acidity
  • Transalkylation
  • USY

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

Transalkylation of toluene with cumene over zeolites Y dealuminated in solid-state : Part II. Effect of the introduced Lewis acid sites. / Mavrodinova, V.; Popova, M.; Mihályi, R. M.; Páł, Borbély G.; Minchev, Ch.

In: Applied Catalysis A: General, Vol. 248, No. 1-2, 08.08.2003, p. 197-209.

Research output: Contribution to journalArticle

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