Catalytic activity of choline modified Fe(III) montmorillonite

Phillip J. Wallis, William P. Gates, Janet L. Scott, Antonio F. Patti

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

A series of mixed-cation organoclays, containing both Fe3+ and choline+ cations, were prepared using montmorillonite and tested for catalytic activity in three Fe3+-mediated reactions: the oxidative coupling of 2-naphthol, coupling of anthrone and a Lewis-acid catalysed indole conjugate addition. Clays with different Fe3+:choline+ ratios were required to achieve maximum catalytic activity in each reaction. For coupling of both 2-naphthol and anthrone, the most effective catalysts, as measured by the turnover frequency (TOF), were mixed Fe3+/choline+ clays of varying ratios, but the catalytic efficiency of Fe3+ montmorillonite in the conjugate addition of indole with methyl vinyl ketone decreased with the addition of choline+. This result could potentially be explained by the effect of choline+ decreasing the accessibility of Lewis acid domains. The results of this study provide proof that it is possible to tune mixed-cation clays with maximum catalytic activity in specific reaction types for specific substrates. Such mixed-cation organoclays offer advantages over traditional clay-based sorbents in environmental remediation applications, as they have the potential to bind organic contaminants selectively, via interaction with surface-exchanged organic cations, and neutralise organic molecules through catalytic exchange cations that are also present on the clay surface.
Original languageEnglish
Pages (from-to)336-340
Number of pages5
JournalApplied Clay Science
Volume53
Issue number2
DOIs
Publication statusPublished - Aug 2011

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Bentonite
Choline
montmorillonite
Cations
Catalyst activity
cation
clay
organoclay
Lewis Acids
Organoclay
acid
ketone
accessibility
Sorbents
ion exchange
turnover
remediation
catalyst
substrate
Impurities

Cite this

Catalytic activity of choline modified Fe(III) montmorillonite. / Wallis, Phillip J.; Gates, William P.; Scott, Janet L.; Patti, Antonio F.

In: Applied Clay Science, Vol. 53, No. 2, 08.2011, p. 336-340.

Research output: Contribution to journalArticle

Wallis, Phillip J. ; Gates, William P. ; Scott, Janet L. ; Patti, Antonio F. / Catalytic activity of choline modified Fe(III) montmorillonite. In: Applied Clay Science. 2011 ; Vol. 53, No. 2. pp. 336-340.
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