Paramagnetic ionic liquids as “liquid fixed-bed” catalysts in flow application

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 173; no. 2; pp. 536 - 540
• Main Authors: Misuk, V., Breuch, D., Löwe, H.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 15.09.2011; Elsevier
• Subjects: Applied sciences; Bubbling; Catalysis; Catalysts; Catalytic reactions; Chemical engineering; Chemistry; esterification; Esters; Exact sciences and technology; Flow chemistry; General and physical chemistry; Ionic liquids; Liquid fixed-bed; Liquids; Magnetic ionic liquids; Micro-structured reactor; Reactors; Solvents; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Micro-structured reactor; Magnetic ionic liquids; Liquid fixed-bed; Flow chemistry; Bubbling; Design; Catalytic reaction; Reactor; Fixed bed; Catalyst; Esterification; Ionic liquid
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2011.05.057

[Display omitted] ► Paramagnetic ionic liquid [BMIM]Fe 2Cl 7 used as fixed liquid catalyst in micro-structured reactors for esterification reaction. ► Catalysts is fixed by external magnetic forces of NdFeB magnets. ► The magnetically fixed liquid forms a new type of a liquid fixed-bed (LFB) catalyst. ► The esterification of cyclohexanol with acetic acid gives 78.5% (GC) yield of the respective ester within 1.3 s. ► LFBs with additional functional groups or ligands opens-up new and unusual processing in continuous micro flow applications. The structural diversity of Ionic Liquids is well-known and widely used to generate solvents designed for special applications. Magnetic as well as catalytic properties have been described previously. To our best knowledge we report the first time about the combination of both, the magnetic and catalytic behaviour of imidazole based magnetic ionic liquids was used to establish a so-called liquid fixed-bed (LFB) in a micro-/meso-structured reactor. As proof of priciple the esterification of Ac 2O with cyclohexanol was investigated by bubbling generated regular microdroplets of the reaction mixture through the magnetically fixed ionic liquid catalyst. With residence times of approx. 1.4 s a yield of 78.5% of the target ester molecule was achieved.