Investigation of the stability of Ce[O.sub.2], [V.sub.2][O.sub.5] and CeV mixed oxide on the partial oxidation of propane

The cerium-vanadium mixed oxide was synthesized by complexation method. XRD patterns of the (CeV) mixed oxide showed the formation of CeV[O.sub.4] phase and segregated Ce[O.sub.2]. Incorporation of vanadium into the ceria structure improved the redox ability of ceria. The results showed that the activity of the (CeV) mixed oxide was higher than of the vanadium oxide ([V.sub.2][O.sub.5]) for the partial oxidation of propane. Both catalysts showed similar hydrogen selectivity but significant deactivation with time on stream. Investigation by XRD diffractograms of [V.sub.2][O.sub.5] after reaction showed sintering of [V.sub.2][O.sub.5] and different oxidation states after reaction, while the crystallites and the structure of the mixed oxide CeV[O.sub.4] remained unchanged. The deactivation of the mixed oxide (CeV) with time on stream can be explained by insufficient oxygen supply to restore the Ce[O.sub.2] species at the surface.