We studied the adsorption and thermal behavior of the nitrile-functionalized ionic liquid (IL) [CCNCIm][TfN] on Au(111) and Pt(111) between 150 and 600 K. Ultrathin films were prepared at 150 K by physical vapor deposition (PVD) and were characterized by angle resolved X-ray photoelectron spectroscopy (ARXPS). At 150 K, the IL adsorbs intact with a similar orientation on both surfaces: In the first layer, the so-called wetting layer, the cation lies flat on the surface and the anion is bound in -configuration with the SO groups toward the surface and the CF groups away from the surface.
View Article and Find Full Text PDFWe present the preparation and investigation of a fluorine-free surface-active bis-N-heterocyclic carbene (NHC) platinum(II) complex - trans-[Pt(mPEGCIm)Cl] - for interface-enhanced supported ionic liquid phase (SILP) catalysis within a group of (mPEG)-substituted ionic liquids (ILs) ([(mPEG)Im][A] ILs). The complex was characterized by means of single-crystal X-ray diffraction (scXRD) analysis and multinuclear (H, C, Pt) NMR spectroscopy, indicating the presence of two almost equimolar syn-anti-rotamers of the square-planar complex in solution. Angle-resolved X-ray photoelectron spectroscopy (ARXPS) revealed pronounced interface-accumulation of trans-[Pt(mPEGCIm)Cl] in IL solutions of [(mPEG)Im][A] (A=I and PF ).
View Article and Find Full Text PDFIn this work, we performed a detailed analysis of the x-ray photoemission spectroscopy (XPS) of the Mn 2peak for MnO(001) thin films. This is a challenging task since MnOis composed of two different cations, Mnat tetrahedral and Mnat octahedral sites, which both contribute to the XPS spectra. The oxide spectra consist of many multiplets arising from the angular momentum coupling of the open Mn 2and 3shells, thus increasing the spectrums' complexity.
View Article and Find Full Text PDFThe concept of a solid catalyst with an ionic liquid layer (SCILL) is a promising approach to improve the selectivity of noble metal catalysts in heterogeneous reactions. In order to understand the origins of this selectivity control, we investigated the growth and thermal stability of ultrathin 1-ethyl-3-methylimidazolium trifluormethanesulfonate [CCIm][OTf] films on Pt(111) by infrared reflection absorption spectroscopy (IRAS) and X-ray photoelectron spectroscopy (XPS) in time-resolved and temperature-programmed experiments. We combined these spectroscopy experiments with scanning tunneling microscopy (STM) to obtain detailed insights into the orientation and adsorption geometry of the ions in the first IL layer.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2022
Although clean energy generation utilizing the Oxygen Reduction Reaction (ORR) can be considered a promising strategy, this approach remains challenging by the dependence on high loadings of noble metals, mainly Platinum (Pt). Therefore, efforts have been directed to develop new and efficient electrocatalysts that could decrease the Pt content (e.g.
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