Pt-supported nanocrystalline ceria-zirconia doped with La, Pr or Gd: factors controlling syngas generation in partial oxidation/autothermal reforming of methane or oxygenates

Vladislav A. Sadykov 1Natalia V. Mezentseva 1Galina M. Alikina 1Anton I. Lukashevich 1Yulia V. Borchert 2Tatyana G. Kuznetsova 1Vyacheslav P. Ivanov 1Sergei N. Trukhan 1Eugenii A. Paukshtis 1Vitalii S. Muzykantov 1Julian Ross 3Erhard Kemnitz 4

1. Boreskov Institute of Catalysis (BIC), pr. akad. Lavrentieva, 5, Novosibirsk 630090, Russian Federation
2. University of Bremen, Otto-Hahn-Allee, Bremen 28359, Germany
3. University of Limerick (UL), Plassey Technological Park, Limerick 02098, Ireland
4. Humboldt University, Institute for Chemistry (HU-CH), Brook-Tailor, 2, Berlin D-12489, Germany

Abstract

These work considers effect of doping of nanocrystalline CeO2-ZrO2 supports with La, Pr or Gd cations on the oxygen mobility, surface features and properties of supported Pt as related to CH4 or acetone transformation into syngas at short contact times. Samples surface features were studied by SIMS and FTIRS of adsorbed CO or NO. The oxygen mobility was characterized by the oxygen isotope exchange and H2 TPR. Catalytic activity was studied in the flow installation using diluted feeds. Within each series, for both reactions, catalytic activity correlates with the Pt dispersion controlled by the oxidized samples ability to stabilize Pt2+ cations as precursors of small reactive Pt clusters formed under reaction conditions. Concentration of these cations correlates with the density of Lewis acid sites -Me4+ cations as well as domain boundaries. Among samples of different series, at comparable Pt dispersion, the highest performance was demonstrated by La-doped system, which correlates with the highest surface/near-surface oxygen mobility. This, is turn, correlates with the lowest strength of Ce-O and Zr-O bonds in the surface layer as judged by the ratio of CeO+/Ce+ and ZrO+/Zr+ ion currents by SIMS. This work is in part supported by INTAS 05-1000005-7663, RFBR-CNRS 05-03-34761 and ISTC 2529 and 3234 Projects

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Presentation: Oral at E-MRS Fall Meeting 2006, Symposium B, by Vladislav A. Sadykov
See On-line Journal of E-MRS Fall Meeting 2006

Submitted: 2006-05-14 16:38
Revised:   2009-06-07 00:44
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