Structure and reactivity of surface oxides on Pt(110) during catalytic CO oxidation
Ackermann, M. D. (ESRF (Grenoble, França))
Pedersen, T. M. (University of Aarhus. Department of Physics and Astronomy)
Hendriksen, B. L. M. (Leiden University. Kamerlingh Onnes Laboratory)
Robach, O. (Commissariat à l'Énergie Atomique et aux Énergies Alternatives (França))
Bobaru, S. C. (Leiden University. Kamerlingh Onnes Laboratory)
Quirós, Carlos (Universidad de Oviedo. Departamento de Física)
Kim, H. (ESRF (Grenoble, França))
Hammer, B. (University of Aarhus. Department of Physics and Astronomy)
Ferrer Fàbregas, Salvador (Universitat Autònoma de Barcelona)
Frenke, J. W. M. (Leiden University. Kamerlingh Onnes Laboratory)
American Physical Society

Data:	2005
Resum:	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 O2/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 O2 and CO are present and at sufficiently high temperatures. Density functional theory calculations indicate that the commensurate oxide is stabilized by carbonate ions (CO2−3). Both oxides have a substantially higher catalytic activity than the bulk-terminated Pt surface.
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; Versió publicada
Publicat a:	Physical review letters, Vol. 95, Issue 25 (December 2005) , p. 255505, ISSN 1079-7114

DOI: 10.1103/PhysRevLett.95.255505

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