MCM22 is a very active and selective catalyst for the skeletal isomerization of butene. At temperatures up to 775 K, Pt-MCM22 gives good results in the dehydroisomerization of n-butane, achieving higher yields of isobutene than does Pt-ZSM5. Most notably, the formation of cracking products is low. Alternatively, MCM22 can also be used as an isomerization catalyst in combination with Pt-ZSM5 in order to increase the yield of isobutene in dehydroisomerization. A disadvantage of the MCM22 materials, however, is their moderate stability, especially at higher temperatures. During calcination/reduction of Pt-MCM22 partial dealumination of the framework occurs, leading to enhanced deactivation by coking. (C) 2000 Academic Press.