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Supported ruthenium catalysed selective hydrogenation of citral in presence of [NTf2]- based ionic liquids

Arras, Jürgen ; Ruppert, Dominik ; Claus, Peter :
Supported ruthenium catalysed selective hydrogenation of citral in presence of [NTf2]- based ionic liquids.
[Online-Edition: http://dx.doi.org/10.1016/j.apcata.2009.09.034]
In: Applied Catalysis A: General, 371 (1-2) pp. 73-77.
[Artikel], (2009)

Offizielle URL: http://dx.doi.org/10.1016/j.apcata.2009.09.034

Kurzbeschreibung (Abstract)

The influence of ionic liquids (ILs) based on the bis(trifluoromethanesulfonyl)amide anion ([BMIM][NTf₂] and [HMIM][NTf₂]) on the alumina supported ruthenium catalysed liquid-phase hydrogenation of citral was investigated applying these ILs as additive. For characterisation ICP-OES, hydrogen pulse chemisorption and nitrogen physisorption were applied, the latter was used after reaction to identify the presence of an ionic liquid layer on the catalyst. The catalytic results show that under the chosen reaction conditions (373 K, 7 MPa H₂, 0.3 mol L⁻¹ citral), additives like [NTf₂]− based ionic liquids change the intramolecular selectivity (C=O vs. C=C hydrogenation) in a way that the desired unsaturated alcohols geraniol and nerol are the main products (Smax = 46% at X = 50% compared to only 25% for neat Ru/Al₂O₃). Concerning the catalyst activity a decrease of the initial turnover frequency (0.048 s⁻¹) in comparison to the IL-free catalyst (0.140 s⁻¹) was observed. The results indicate that in presence of [BMIM][NTf₂] and [HMIM][NTf₂] the site-time yields towards citronellal were more decreased than for geraniol and nerol enhancing the selectivity of the latter ones.

Typ des Eintrags: Artikel
Erschienen: 2009
Autor(en): Arras, Jürgen ; Ruppert, Dominik ; Claus, Peter
Titel: Supported ruthenium catalysed selective hydrogenation of citral in presence of [NTf2]- based ionic liquids
Sprache: Englisch
Kurzbeschreibung (Abstract):

The influence of ionic liquids (ILs) based on the bis(trifluoromethanesulfonyl)amide anion ([BMIM][NTf₂] and [HMIM][NTf₂]) on the alumina supported ruthenium catalysed liquid-phase hydrogenation of citral was investigated applying these ILs as additive. For characterisation ICP-OES, hydrogen pulse chemisorption and nitrogen physisorption were applied, the latter was used after reaction to identify the presence of an ionic liquid layer on the catalyst. The catalytic results show that under the chosen reaction conditions (373 K, 7 MPa H₂, 0.3 mol L⁻¹ citral), additives like [NTf₂]− based ionic liquids change the intramolecular selectivity (C=O vs. C=C hydrogenation) in a way that the desired unsaturated alcohols geraniol and nerol are the main products (Smax = 46% at X = 50% compared to only 25% for neat Ru/Al₂O₃). Concerning the catalyst activity a decrease of the initial turnover frequency (0.048 s⁻¹) in comparison to the IL-free catalyst (0.140 s⁻¹) was observed. The results indicate that in presence of [BMIM][NTf₂] and [HMIM][NTf₂] the site-time yields towards citronellal were more decreased than for geraniol and nerol enhancing the selectivity of the latter ones.

Titel der Zeitschrift, Zeitung oder Schriftenreihe: Applied Catalysis A: General
Band: 371
(Heft-)Nummer: 1-2
Freie Schlagworte: Ionic liquid; Additive; Modifiers; Liquid-phase hydrogenation; Citral; ?,?-Unsaturated aldehydes; Intramolecular selectivity
Fachbereich(e)/-gebiet(e): Fachbereich Chemie
Fachbereich Chemie > Technische Chemie > Technische Chemie II
Fachbereich Chemie > Technische Chemie
Hinterlegungsdatum: 21 Sep 2009 07:43
Offizielle URL: http://dx.doi.org/10.1016/j.apcata.2009.09.034
Zusätzliche Informationen:

Available online 8. Oktober 2009

ID-Nummer: 10.1016/j.apcata.2009.09.034
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