Structure and Reactivity of Surface Oxides on Pt(110) during Catalytic CO Oxidation

Journal Article · Fri Dec 16 00:00:00 EST 2005 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.95.255505· OSTI ID:20699711

Ackermann, M D ^[1]; Pedersen, T M; Hammer, B ^[2]; Hendriksen, B L.M.; Bobaru, S C; Frenken, J W.M. ^[3]; Robach, O ^[4]; Popa, I; Kim, H ^[1]; Quiros, C ^[5]; Ferrer, S ^[6]

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1. ESRF, 6, rue Jules Horowitz, F-38043 Grenoble cedex (France)
2. Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)
3. Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden (Netherlands)
4. CEA-Grenoble DRFMC/SI3M/PCM17, rue des Martyrs, 38054 Grenoble cedex 9 (France)
5. Departamento de Fisica, Faculdad de Ciencias, Universidad de Oviedo, Avda. Calvo Sotelo, s/n, 33007 Oviedo (Spain)
6. CELLS - ALBA, Edifici Ciencies Nord. Modul C-3 centra, Campus Universitari de Bellaterra, Universita Autonoma de Barcelona, 08193 Bellaterra (Spain)

We present the first structure determination by surface x-ray diffraction during the restructuring of a model catalyst under reaction conditions, i.e., at high pressure and high temperature, and correlate the restructuring with a change in catalytic activity. We have analyzed the Pt(110) surface during CO oxidation at pressures up to 0.5 bar and temperatures up to 625 K. Depending on the O{sub 2}/CO pressure ratio, we find three well-defined structures: namely, (i) the bulk-terminated Pt(110) surface, (ii) a thin, commensurate oxide, and (iii) a thin, incommensurate oxide. The commensurate oxide only appears under reaction conditions, i.e., when both O{sub 2} and CO are present and at sufficiently high temperatures. Density functional theory calculations indicate that the commensurate oxide is stabilized by carbonate ions (CO{sub 3}{sup 2-}). Both oxides have a substantially higher catalytic activity than the bulk-terminated Pt surface.

• OSTI ID: 20699711
• Journal Information: Physical Review Letters, Vol. 95, Issue 25; Other Information: DOI: 10.1103/PhysRevLett.95.255505; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON MONOXIDE
CARBONATES
CATALYSIS
CATALYSTS
DENSITY FUNCTIONAL METHOD
OXIDATION
PLATINUM
PRESSURE RANGE KILO PA
REACTIVITY
SURFACES
TEMPERATURE RANGE 0400-1000 K
X-RAY DIFFRACTION