Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 57: Surface Chemical Reactions and Heterogeneous Catalysis II
O 57.10: Vortrag
Donnerstag, 29. März 2007, 18:00–18:15, H38
Surface studies of simple and complex ionic liquid systems using XPS — •Manuela Killian1, Christian Potzner1, Till Cremer1, Jörg Michael Gottfried1, Natalie Müller2, Dirk Gerhard2, Peter Wasserscheid2, Florian Maier1, and Hans-Peter Steinrück1 — 1Lehrstuhl für Physikalische Chemie II, Universität Erlangen, Egerlandstr. 3, 91058 Erlangen — 2Lehrstuhl für Chemische Reaktionstechnik, Universität Erlangen
Ionic liquids (ILs) - organic salts with melting points below 100°C - represent a new class of materials in liquid phase physics and chemistry. In surface science, ILs open up unprecedented possibilities for surface studies of phenomena related to liquids in general because of their negligible vapour pressures even at elevated temperatures. Our studies focus on two ILs consisting of the same cation but different anions, namely 1-ethyl-3-methylimidazolium ethylsulfate (EMIM EtSO4) and 1-ethyl-3-methylimidazolium bis(tri-fluoromethane-sulfon)amide (EMIM BTA). To determine surface composition and molecular orientation, angle dependent XP spectra were recorded for the pure ILs, their mixtures, and solutions comprising a dissolved platinum salt as model catalyst. In the latter case, we demonstrate a selective enrichment of the platinum cation at the surface.[1] The basic understanding of surface/interface enrichment effects is important for all kinds of multiphasic catalysis operations employing ionic liquids. This work was supported by the DFG through SPP1191.
[1] F. Maier et al., Angew. Chem. Int. Ed. 45 (2006) 7778.