AVS 50th International Symposium
    Surface Science Wednesday Sessions
       Session SS-WeP

Paper SS-WeP17
Adsorption and Reaction of NO and CO on CeO2(111) and Ce0.8Zr0.2O2(111) Surfaces

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: S. Azad, Pacific Northwest National Laboratory
Authors: S. Azad, Pacific Northwest National Laboratory
M.H. Engelhard, Pacific Northwest National Laboratory
J. Szanyi, Pacific Northwest National Laboratory
C.H.F. Peden, Pacific Northwest National Laboratory
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The adsorption and reaction of NO and CO on oxidized and reduced CeO@sub 2@(111)/YSZ(111) surfaces have been studied using temperature-programmed desorption (TPD) and x-ray photoelectron spectroscopy (XPS). NO desorbs molecularly from the fully oxidized and reduced surfaces, when adsorbed at 125 K, in three desorption states at 157, 196 and 300 K. NO reacts non-dissociatively on the fully oxidized surface. Reactivity of the high temperature annealed and sputtered surfaces, is significantly higher compared to the fully oxidized surface. Adsorption of NO on the reduced surfaces is followed by N-O bond dissociation producing adsorbed N and O atoms, which subsequently form a variety of products during TPD. A large fraction of CO molecules, adsorbed on the sputtered ceria surface, is oxidized to CO@sub 2@ whereas CO desorbs molecularly from the fully oxidized CeO@sub 2@(111)/YSZ(111) surface, when adsorbed at 125 K. These results will be compared with the ongoing studies on adsorption and reaction of NO and CO on Ce@sub 0.8@Zr@sub 0.2@O@sub 2@(111)/YSZ(111).