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.
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Contribution No. 831 from the Solid State and Structural Chemistry Unit.
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Kannan, K.R., Kulkarni, G.U. & Rao, C.N.R. Investigations of Fe-Ru bimetallic catalysts by in situ Mössbauer and EXAFS studies. Catal Lett 14, 149–163 (1992). https://doi.org/10.1007/BF00765229
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DOI: https://doi.org/10.1007/BF00765229