Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-I-4SELECTIVE HYDROGENATION OF CINNAMALDEHYDE OVERSUPPORTED IONIC LIQUID CATALYSTS (SILCA)Pasi Virtanen, Jyri-Pekka Mikkola, Tapio SalmiProcess Chemistry Centre, Åbo Akademi University, Laboratory of industrial chemistry,FI-20500, Turku, Finlande-mail: pasi.virtanen@abo.fiIonic liquids, or room temperature salt melts, have been a hot topic in many researchareas in recent times. The significance of ionic liquids comes from the fact that they arecompletely ionic compounds and are liquid at ambient conditions. Ionic liquids are a highlysolvating, non-coordinating medium in which many organic and inorganic compoundsdissolve. Many of them have common characteristic features like the often negligible vaporpressure (~10 –8 bar), wide liquidus range, high thermal stability, wide electrochemicalwindow as well as good ion conductivity 1,2 . Ionic liquids have shown a good performance invarious kinds of catalytic reactions as well as in the preparation of nanostructured materialsand nanoparticles suitable for catalysis 3,4 . Indeed, catalysis is one of the areas, where ionicliquids represent a considerable potential, also considering the fact that the immobilized ionicliquid catalysts result in a very efficient use of the ionic liquid and relatively short diffusiondistances compared to conventional two-phase systems.Catalysts were prepared according to the method described previously 5 . Palladium acetylacetonate, and ionic liquid were dissolved in acetone. Solution was poured over an activecarbon cloth (ACC), Kynol ® . Acetone was evaporated in a rotary evaporator leavingPd(acac) 2 dissolved in ionic liquid supported on ACC. The catalysts were pre-treated in abatch reactor at 120 °C under 10 bar hydrogen flow. This procedure resulted into formation ofPd nano-particles in ionic liquid immobilized on ACC (Fig. 1). The catalysts were applied inthe hydrogenation of cinnamaldehyde. Cinnamaldehyde, a multi saturated aldehyde, is anindustrially important precursor for many fine chemical products, flavoring agents, perfumes,fungicides and steel corrosion inhibitors. Experiments were conducted in the batch reactor, atconstant temperature (from 60 to 150 °C) and constant hydrogen pressure (from 5 to 30 bar).The progress of the reaction was monitored by withdrawing small samples from reactor andanalyzing them by gas chromatography.218