Regensburg 2013 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 49: Colloids and Complex Liquids III

CPP 49.2: Vortrag

Freitag, 15. März 2013, 10:00–10:15, H40

In situ high pressure XPS for ionic liquid - gas phase reaction studies — •Inga Niedermaier¹, Wei Wei², Christian Papp¹, Claudia Kolbeck¹, Sandra Krick Calderòn¹, Florian Maier¹, Peter Schulz², Peter Wasserscheid², and Hans-Peter Steinrück¹ — ¹Lehrstuhl für Physikalische Chemie II — ²Lehrstuhl für Chemische Reaktionstechnik, Egerlandstr. 3, 91058 Erlangen

Ionic liquids (ILs) are molten salts composed solely of ions with a melting point below 100 ^∘C and a negligible vapour pressure at room temperature. X-ray photoelectron spectroscopy (XPS) has proven to be a versatile tool for surface investigations of these materials under ultrahigh vacuum conditions (UHV).^[1] It even allows to monitor reactions occurring in the near-surface region of ILs.^[2] We demonstrate to our knowledge the first gas-liquid reaction studies between an IL and a gaseous species by means of in situ XPS in the mbar pressure regime. The anion of the IL [Me₂N⁺(CH₂CH₂OH)₂][H₂NCH₂CH₂SO₃⁻] was functionalised with an amine group (H₂N⁻), in analogy to aqueous amine systems for carbon dioxide capture applications. ILs are considered as potential replacements for these aqueous amines due to the extremely low vapour pressure and their typically high thermal stability. Under CO₂ pressures up to 0.9 mbar, in situ XPS reveals reaction schemes involving carbamate and ammonium formation via carbamic acid as an intermediate. Supported by the Cluster of Excellence - Engineering of Advanced Materials. 1. H. P. Steinrück, Phys Chem Chem Phys, 2012, 14, 5010 2. I. Niedermaier et al., Chemphyschem, 2012, 13, 1725