IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Thursday Sessions
       Session SS1-ThA

Paper SS1-ThA1
Thin Ce@sub x@Zr@sub 2-x@O@sub 2@(111) Films as Model Catalytic Converter Oxygen Storage Materials

Thursday, November 1, 2001, 2:00 pm, Room 121

Session: Catalysis on Model Systems
Presenter: C.H.F. Peden, Pacific Northwest National Laboratory
Authors: C.H.F. Peden, Pacific Northwest National Laboratory
T. He, Pacific Northwest National Laboratory
G.S. Herman, Pacific Northwest National Laboratory
Y.-J. Kim, Taejon National University of Technology
S. Thevuthasan, Pacific Northwest National Laboratory
V. Shutthanandan, Pacific Northwest National Laboratory
D. McCready, Pacific Northwest National Laboratory
J. Szanyi, Pacific Northwest National Laboratory
Correspondent: Click to Email
Oxygen storage (OS) materials, usually consisting of ceria (CeO@sub 2@) or modified ceria, are used in automobile catalytic converters to effectively damp deviations in the exhaust air/fuel (A/F) ratio in order to optimize the activity of the precious metal catalyst. We are using thin films of CeO@sub 2@ and ceria-zirconia (Ce@sub x@Zr@sub 2-x@O@sub 2@) as models for fundamental studies of the oxygen uptake, storage, and release properties of these materials. This presentation will emphasize the characterization (by x-ray diffraction, atomic force microscopy, reflection high-energy electron diffraction, low-energy electron diffraction, x-ray photoelectron spectroscopy (XPS) and diffraction, and Rutherford backscattering spectrometry and high-energy ion channeling) of model CeO@sub 2@ and Ce@sub x@Zr@sub 2-x@O@sub 2@ (x = 1.0, 0.9, 0.8, 0.7, and 0.6) thin films will be presented. A wide range of growth parameters using oxygen plasma-assisted molecular beam epitaxy have been used, and successful production of pure-phase, single-crystalline epitaxial oxide films has been achieved for x > 0.6. At higher Zr levels, evidence for phase-separation is observed. We will also report results of XPS and carbon monoxide temperature-programmed desorption experiments that provide evidence for markedly enhanced kinetics of oxygen storage and release upon doping of CeO@sub 2@ by Zr.