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Lindsay Merte

Visiting research fellow

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Dynamic Behavior of Tin at Platinum Surfaces during Catalytic CO Oxidation

Author

  • Harald J. Wallander
  • Dorotea Gajdek
  • Stefano Albertin
  • Gary Harlow
  • Nicolas Braud
  • Lars Buß
  • Jon Olaf Krisponeit
  • Jan Ingo Flege
  • Jens Falta
  • Edvin Lundgren
  • Lindsay R. Merte
Show all

Summary, in English

Platinum-tin surfaces are active for CO oxidation, but their activity and the effects of tin oxide phases that form under reaction conditions are poorly understood. We have studied surface alloys of tin prepared on platinum single crystals during catalytic CO oxidation using near-ambient-pressure X-ray photoemission spectroscopy. On the flat terraces of Sn/Pt(111), a wetting layer of Sn(II) surface oxide forms, while on the stepped Sn/Pt(223) surface, 3D clusters of Sn(IV) oxide are formed. Oxidation of tin by O2 competes with the reduction of the oxides by CO under reaction conditions. Oxides that do not completely cover the surface can be reduced to metallic tin, while a fully covering layer of Sn(II) oxide cannot, showing the importance of oxide edge sites for the reduction process. The samples where 2D oxide layers are formed show a higher CO oxidation activity than for pure platinum at low temperatures, while the Sn(IV) oxide clusters on the stepped surfaces do not affect the measured CO oxidation rate. We therefore identify 2D Sn(II) oxide as an active phase for CO oxidation. While oxide island edges appear to make only minor contributions to conversion under these conditions, reactions at these sites play a major role in determining the phases present and their transformations.

Department/s

  • LU Profile Area: Light and Materials
  • LTH Profile Area: Nanoscience and Semiconductor Technology
  • NanoLund: Centre for Nanoscience
  • Synchrotron Radiation Research
  • LTH Profile Area: Photon Science and Technology

Publishing year

2023-12

Language

English

Pages

16158-16167

Publication/Series

ACS Catalysis

Volume

13

Issue

24

Document type

Journal article

Publisher

The American Chemical Society (ACS)

Topic

  • Inorganic Chemistry

Keywords

  • alloys
  • CO oxidation
  • operando
  • oxides
  • platinum
  • stepped surfaces
  • tin

Status

Published

ISBN/ISSN/Other

  • ISSN: 2155-5435