Magnesia alumina spinels and composites have been developed as attrition resistant supports for the magnesium molybdate which selectively oxidizes butane to butadiene. As with the magnesia supports the optimum yields are obtained with 15%-25% MoO3 together with small amounts of alkali metals to minimize carbon oxides. Vanadia is a promoter which allows for lower temperatures and less coking. Designed experiments were used to model and optimize the reaction conditions and the amounts of vanadia/alkali metal. Characterization of these catalysts by XRD, SEM and TEM indicates that particles of magnesium molybdate are found on both the occluded MgO and on the magnesium aluminate spinel surface of the alumina matrix. These molybdate particles are larger and more stable than those found on the MgO support. The result is that these catalysts are less active initially but more stable with time than those on MgO.