Co2+-exchanged SAPO-5 and SAPO-34 as efficient heterogeneous catalysts for aerobic epoxidation of alkenes

Co-SAPO-5 and Co-SAPO-34 were prepared by a simple ion-exchange route and firstly applied in the aerobic epoxidation of alkenes. Both catalysts exhibited high activities in the epoxidation of alkenes with air to achieve 92.0-91.9 mol% conversion with the epoxide selectivity of 89.5-90.5% for styrene, 71.6-80.0 mol% conversion with 94.8-95.0% selectivity for a-pinene, and 953-96.8 mol% conversion with 75.2-73.6% selectivity for a-methyl styrene. Recycling studies and control experiments showed the recyclability and stability of Co-SAPO-5 and Co-SAPO-34 as heterogeneous catalysts. (C) 2012 Elsevier B.V. All rights reserved.