Ammoxidation of ethane V. Solid-state ion exchange to prepare cobalt zeolite catalysts

Earlier we reported prior dealumination of Y zeolite provides much higher activity and selectivity for the ammoxidation of ethane to acetonitrile. In this manuscript, we describe the preparation of active dealuminated Y catalysts by both aqueous and solid-state ion-exchange procedures. Although it is difficult to achieve exactly the same levels of exchange by these two techniques, in general solid state exchange of cobalt ion resulted in less cobalt in the exchange sites, but higher yields of acetonitrile at lower Co/Al values. Solid-state exchange of three different zeolite topologies (ZSM-5, beta, and USY) also produced enhanced selectivity for NH3 incorporation into acetonitrile. (C) 1999 Elsevier Science B.V. All rights reserved.