Publications by authors named "Jade Barreto"

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.

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We 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 ).

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In 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.

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The 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.

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Article Synopsis
  • MnO(001) thin films were grown on an Au(111) substrate, and their interaction with water molecules was studied using infrared reflection absorption spectroscopy (IRAS) and thermal desorption spectroscopy (TDS).
  • The research identified two types of water binding pathways on the oxide films: one where water molecules adsorb on flat surfaces (terraces), and another where water breaks apart at defects, specifically oxygen vacancies influenced by manganese (Mn) sites.
  • Both IRAS and TDS findings emphasize the significant role of surface defects in how MnO interacts with adsorbed water, affecting its overall adsorption behavior.
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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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