Probing Oxide Reduction and Phase Transformations at the Au-TiO2 Interface by Vibrational Spectroscopy

Anna Pougin, Alexander Lüken, Christina Klinkhammer, Dennis Hiltrop, Max Kauer, Katharina Tölle, Martina Havenith-Newen, Karina Morgenstern, Wolfgang Grünert, Martin Muhler, Jennifer Strunk

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

By a combination of FT-NIR Raman spectroscopy, infrared spectroscopy of CO adsorption under ultrahigh vacuum conditions (UHV-IR) and Raman spectroscopy in the line scanning mode the formation of a reduced titania phase in a commercial Au/TiO2 catalyst and in freshly prepared Au/anatase catalysts was detected. The reduced phase, formed at the Au-TiO2 interface, can serve as nucleation point for the formation of stoichiometric rutile. TinO2n−1 Magnéli phases, structurally resembling the rutile phase, might be involved in this process. The formation of the reduced phase and the rutilization process is clearly linked to the presence of gold nanoparticles and it does not proceed under similar conditions with the pure titania sample. Phase transformations might be both thermally or light induced, however, the colloidal deposition synthesis of the Au/TiO2 catalysts is clearly ruled out as cause for the formation of the reduced phase.

Original languageEnglish
Pages (from-to)1744-1753
Number of pages10
JournalTopics in Catalysis
Volume60
Issue number19-20
DOIs
StatePublished - 1 Dec 2017
Externally publishedYes

Keywords

  • Anatase
  • CO oxidation
  • Gold nanoparticles
  • Raman spectroscopy
  • Rutile
  • TiO2
  • UHV-FTIR

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