Surface studies of model supported catalysts: NO adsorption on Rh/CeO{sub 2}(001)
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6201 (United States)
The adsorption and reaction of NO on a model catalyst composed of Rh supported on ceria has been studied. CeO{sub 2} films were grown epitaxially by laser ablation onto SrTiO{sub 3}(001) substrates. X-ray diffraction and transmission electron microscopy indicate the films are single crystalline with (001) orientation. Comparison of experimental and computer simulated ion scattering distributions indicate that an annealed CeO{sub 2} surface is well ordered and is composed of both O and Ce terminated domains. Exposures to CO and H{sub 2} at various temperatures had little or no effect upon the ceria. Photoemission from the Ce 4d levels exhibits complex features that differ between a sputtered and a fully oxidized surface. NO does not adsorb on the Rh free, fully oxidized surface, but does adsorb upon a sputter reduced surface. The thermally induced conversion from molecular NO to atomic N was measured by both N 1s photoemission and x-ray absorption as a function of Rh coverage to determine substrate effects on Rh surface chemistry. Rh deposited on sputtered ceria is more active for NO decomposition and yields higher N{sub 2} desorption temperatures than does Rh on the fully oxidized support. {copyright} {ital 1997 American Vacuum Society.}
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 509010
- Report Number(s):
- CONF-961002-; ISSN 0734-2101; TRN: 97:013802
- Journal Information:
- Journal of Vacuum Science and Technology, A, Vol. 15, Issue 3; Conference: 43. national symposium of the American Vacuum Society (AVS), Philadelphia, PA (United States), 14-18 Oct 1996; Other Information: PBD: May 1997
- Country of Publication:
- United States
- Language:
- English
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