Monodisperse magnetic iron colloids grafted with polyisobutene:: A model system for Fischer-Tropsch catalysts?

Iron colloids stabilised with polyisobutene with a radius ranging from 2.1 to 8.2 nm have been prepared and characterised by Mossbauer absorption spectroscopy. Comparison with results reported in the literature on sarcosyl and oleic acid stabilised colloids reveals that the stabilising ligand influences the properties of the colloids. By impregnating an alumina support with a solution of the r = 2.1 nm Fe colloids a model catalyst has been prepared. The first results show that the impregnation was successful. However, due to the low Fe loading, the signal-to-noise ratio is too low to perform good measurements on this model system. Therefore, Fe-colloids will be prepared that are enriched in Fe-57.