Berlin 2008 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 55: Poster Session III - MA 141/144 (Methods: Atomic and Electronic Structure; Particles and Clusters; Heterogeneous Catalysis; Semiconductor Substrates: Epitaxy and Growth+Adsorption+Clean Surfaces+Solid-Liquid Interfaces; Oxides and Insulators: Solid-Liquid Interfaces+Epitaxy and Growth; Phase Transitions; Metal Substrates: Adsorption of Inorganic Molecules+Epitaxy and Growth; Surface Chemical Reactions; Bimetallic Nanosystems: Tuning Physical and Chemical Properties; Oxides and insulators: Adsorption; Organic, polymeric, biomolecular films; etc.)

O 55.53: Poster

Mittwoch, 27. Februar 2008, 18:30–19:30, Poster F

Chemical reactivity of the polar O-ZnO(000-1) surface investigated by vibrational spectroscopy — •Hengshan Qiu, Yuemin Wang, and Christof Wöll — Lehrstuhl für Physikalische Chemie I, Ruhr-Universität Bochum, 44780 Bochum, Germany

Zinc oxide is an important material with a wide range of technological applications in catalysis, solar cells, as gas sensor and in semiconductor devices [1]. In catalysis, the heterogeneous catalyst system Cu/ZnO has been widely applied for the industrial methanol synthesis. Recently, the oxygen terminated polar (000-1) surface has been demonstrated to be the most active surface for methanol synthesis from syngas (CO/CO₂/H₂) on ZnO powders [2]. It is found that the clean, H-free O-ZnO(000-1) surface is (1x3) reconstructed and exposes 0.33 ML O vacancies. In this contribution, the interaction of different molecules (CO, CO₂ CH₂O and HCOOH) with the clean O-ZnO(000-1) surface was studied by high-resolution electron energy loss spectroscopy (HREELS), thermal desorption spectroscopy (TDS) and low-energy electron diffraction (LEED). The present results provide detailed information about the chemical reactivity of defect sites (in particular O vacancies) towards different adsorbates. The corresponding reactions can be monitored by vibrational spectroscopy.

[1] Ch. Wöll, Prog. Surf. Sci. 82 (2007) 55. [2] M. Kurtz, J. Strunk, O. Hinrichsen, M. Muhler, K. Fink, B. Meyer and Ch. Wöll, Angew. Chem. Int. Ed. 2005, 44, 2790