Effets of Cobalt Oxide-Iron Oxide Ratios on the Catalytic Activity of Cobalt Ferrite Spinel Catalysts

The cobalt ferrite spinels Co-x Fe3-x O-4(0.6 < x < 2.4) have been prepared by co-precipitation. The structures of the catalysts were characterized by DTA, X-ray diffraction, surface area and electrical conductivity measurements. The catalytic decomposition of isopropanol was carried out al 325 degrees C using a now system. The results obtained revealed that the activity and selectivity of the catalysts are strongly affected by the structure of the ferrite spinel formed as a result of the solid - solid interaction between Fe2O3 and Co3O4. The normal spinel formed at (x = 1) gives low activity and low selectivity in comparison with the spinels deviated from the stoichiometry. Additionally, a little change in catalytic behaviour observed on increasing the calcination temperature from 400 degrees to 600 degrees C. Correlations between the composition, electronic and catalytic properties of the catalysts are reported.