Interaction of NO with alumina supported palladium model catalysts

Libuda J (2003)


Publication Type: Journal article

Publication year: 2003

Journal

Publisher: Royal Society of Chemistry

Book Volume: 5

Pages Range: 5139-5148

DOI: 10.1039/b309490a

Abstract

The interaction of NO with a well-defined supported Pd model catalyst has been investigated, employing a combination of IR reflection absorption spectroscopy (IRAS) and molecular beam methods. The model catalyst is based on an ordered Al2O3 film, grown on NiAl(110) and has been characterized in detail with respect to its geometric and electronic structure previously. In a first step the interaction of NO with the pure Al 2O3 model support is studied. It is observed that NO slowly decomposes at low surface temperature (100 K), resulting in the formation of a variety of NxOy surface species. The decomposition process involves strong structural transformations of the Al 2O3 film and is initiated at oxide defect sites. The adsorption of NO on the Pd/Al2O3 model system is explored systematically as a function of surface coverage and temperature. For NO adsorption on the Pd particles, characteristic absorption bands are identified by comparison with single crystal data, which are indicative of particle-specific sites such as edges and other defects. At 300 K and above NO dissociation occurs on the Pd particles, whereas the low-temperature decomposition channel on the alumina support is found to be strongly suppressed in the presence of the Pd particles. Finally, co-adsorption of NO with oxygen- and CO-precovered Pd particles is investigated. Preadsorbed oxygen results in the formation of a mixed adsorbate layer with an enhanced NO population of on-top sites on the particles. NO adsorption on a CO layer, on the other hand, gives rise to a compression of the CO layer and an enhanced population of on-top sites by CO.

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How to cite

APA:

Libuda, J. (2003). Interaction of NO with alumina supported palladium model catalysts. Physical Chemistry Chemical Physics, 5, 5139-5148. https://dx.doi.org/10.1039/b309490a

MLA:

Libuda, Jörg. "Interaction of NO with alumina supported palladium model catalysts." Physical Chemistry Chemical Physics 5 (2003): 5139-5148.

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