ABSTRACT
A VMgO catalyst used in the oxidative dehydrogenation of propane (ODHP) reaction has been examined in detail by HREM. As prepared material is shown to consist mainly of MgO crystallites exhibiting an unusual {111} facet termination stabilised by a disordered vanadium containing overlayer. The structural state of the overlayer has been found to vary depending on the gaseous environment to which the catalyst has been subjected. Normal reaction conditions gives rise to a weakly ordered structure whilst strong reducing conditions induce a pronounced structural ordering of the overlayer. Subsequent reoxidation treatments cause the overlayer to revert back to a disordered state. These changes can be correlated with changes in the electrical conductivity of the material.
