Evidence for direct observation by Mössbauer spectroscopy of surface tin atoms in platinum-tin particles

J. P. Candy*, E. Roisin, Jean-Marie Maurice Basset, D. Uzio, S. Morin, L. Fischer, J. Olivier-Fourcade, J. C. Jumas

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

119Sn Mössbauer spectroscopy at 77 K was used to observe surface tin atoms on PtSnx/SiO2 catalysts. Two families of PtSnx/SiO2 catalysts with fully reduced Pt(0) and Sn(0) atoms were prepared following the Surface Organo-metallic Chemistry on Metal strategy. These two families of catalysts exhibit about the same Sn/Pt composition, but very different metallic particle diameters, each with narrow particle size distribution, so that, the ratio between surface tin atoms and "bulk" tin atoms was significantly different for the two families. In addition to the well known "Pt-Sn" bulk alloy with small quadripole splitting, a new Pt-Sn species with large quadripole splitting and isomer shift in the range of Sn(0) was observed. The relative proportion of this species with respect to "Pt-Sn" bulk alloy is greater for small particles than for the larger ones, which suggests that this species is a surface tin atom present in a "Pt-Sn" alloy.

Original languageEnglish (US)
Pages (from-to)55-60
Number of pages6
JournalHyperfine Interactions
Volume165
Issue number1-4
DOIs
StatePublished - Sep 1 2005

Keywords

  • Mössbauer spectroscopy
  • Platinum-tin catalysts
  • Surface organo-metallic chemistry on metal route

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Nuclear and High Energy Physics
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

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