Catalysis Letters

, Volume 14, Issue 2, pp 149–163 | Cite as

Investigations of Fe-Ru bimetallic catalysts by in situ Mössbauer and EXAFS studies

  • K. R. Kannan
  • G. U. Kulkarni
  • C. N. R. Rao
Article

Abstract

In situ Mössbauer and EXAFS investigations have shown that the reduction of iron in the monometallic Fe/SiO2 catalyst is only partial, the reduction being mostly to a ferrous silicate phase. In the bimetallic Fe-Ru/SiO2 catalysts, the proportion of the FeRu alloy formed on reduction increases markedly with the increase in Ru content; clearly, Ru significantly enhances the reduction of iron on SiO2. In the Ru-rich compositions (Ru/Fe 1.0), most of the iron is present in the alloy phase and there is no segregation of α-Fe. A comparative study of the different supports has shown that γ-Al2O3 and SiO2 interact with iron strongly at low reduction temperatures while the TiO2 support interacts at higher temperatures. The presence of traces of Fe3+ often found in reduced Fe-Ru catalysts is shown to arise from the oxidation of fine segregated iron particles on the support.

Keywords

Bimetallic catalysts hydrogenation catalysts Fe-Ru/SiO2 supported Fe-Ru catalysts Fe/SiO2 

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Copyright information

© J.C. Baltzer A.G. Scientific Publishing Company 1992

Authors and Affiliations

  • K. R. Kannan
    • 1
  • G. U. Kulkarni
    • 1
  • C. N. R. Rao
    • 1
  1. 1.Solid State and Structural Chemistry Unit and CSIR Centre of Excellence in ChemistryIndian Institute of ScienceBangaloreIndia

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