Berlin 2018 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 65: Focus Session: Structure and Chemistry of Metal-Oxide Surfaces III
O 65.6: Vortrag
Mittwoch, 14. März 2018, 16:30–16:45, MA 005
Structure and stability of the vicinal ZnO(10-14) surface — •Elin Grånäs1, Björn Arndt1,2, Marcus Creutzburg1,2, Guilherme D.L. Semione1,2, Heshmat Noei1, Andreas Schaefer3, Johan Gustafson3, Vedran Vonk1, and Andreas Stierle1,2 — 1Deutsches-Elektron Synchrotron (DESY), Germany — 2University of Hamburg, Germany — 3Lund University, Sweden
Zinc oxide (ZnO) based catalysts are commonly used, often together with Cu nanoparticles, in important chemical reactions such as methanol synthesis low temperature water-gas shift, and methanol steam reforming. ZnO plays not only the role as nanoparticle support; instead it is much more actively involved in many reactions, with detailed reaction mechanisms under discussion.
The commonly studied low index surfaces of ZnO are polar, resulting in surface instability, while the most stable surface has been suggested to be the vicinal ZnO(10-14) surface. However very little is still known about the equilibrium structure of the vicinal surface and its stability upon gas exposures. Here first studies performed on vicinal ZnO(10-14) single crystals will be presented. Using techniques such as scanning probe microscopy (STM), surface x-ray diffraction (SXRD), and x-ray photoelectron spectroscopy (XPS) we have characterized the bare and water exposed ZnO(10-14) surface. We have confirmed that the bare vicinal surface is stable in UHV and will discuss the atomic structure based on SXRD measurements. We will also discuss chemical and structural changes upon water exposure.