Doctoral thesis
1. In-situ structural investigation of alloy nanoparticles under catalytic reaction conditions
Topic: Alloy nanoparticles play an important role as catalysts during the conversion of harmful gases (e.g. 3 way car catalyst). For the optimization of the catalytic activity and selectivity towards a specific reaction an atomic scale understanding is desired.
Tasks: Growth of alloy nanoparticles on oxide substrates by thermal evaporation with variable composition. Structural characterization of nanoparticles by in-situ x-ray diffraction employing synchrotron radiation1 as a function of the particle composition and size. Analysis of the chemical composition by Auger electron spectroscopy, determination of the surface morphology using atomic force microscopy (AFM). Data evaluation and analysis software adaptation.
2. Structural investigation of chemically active oxide surfaces for fuel cells by surface x-ray diffraction
Topic: Oxide surfaces play a central role for the conversion of chemical into electrical energy in high temperature oxide fuel cells. Fundamental aspects of this process involving oxide surfaces are not understood, which shall be elucidated within this work on the atomic scale using model electrodes.
Tasks: Spatially resolved structural investigation of oxide surfaces using surface x-ray diffraction at synchrotron radiation facilities1. Planning and construction of a novel sample environment for spatially resolved surface x-ray diffraction experiments. Surface composition and structure characterisation by Auger electron spectroscopy and low energy electron diffraction. Data evaluation using existing software.
1ANKA (KIT Karlsruhe), PETRA III (DESY, Hamburg), ESRF (Grenoble))