EFFECTS OF THE METHOD OF PREPARATION OF MGC2O4 AS A SUPPORT PRECURSOR ON THE PROPERTIES OF IRON MAGNESIUM-OXIDE CATALYSTS

Samples of iron/magnesium oxide catalyst in which magnesium oxalate was used as a common support precursor were prepared alternatively from magnesium nitrate (N) and from magnesium acetate (A) and were tested in hydrocarbon synthesis. Sample N showed the higher activity by one order of magnitude while sample A showed better initial selectivity towards alkenes and a slower initial deactivation. BET, X-ray diffraction (XRD), scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and Mossbauer spectroscopy analysis revealed different methods for the formation of the catalyst in all the stages of preparation. Lower activity of sample A was explained by hindered reductibility of the iron component, due to the fact that support effects were affected by individual properties of the support precursor parent materials, as well as by the preparation conditions which they imposed.