|
α,β-unsaturated ketones are widely used in many areas and prepared by oxidation byα,β-unsaturated alcohols, Therefore, selective oxidation ofα,β-unsaturated alcohols attracts significant attention. Nowadays, the process accomplished with homogeneous catalysts. In spite of its high activity, the process suffers from high cost and environmental pollution, which hamper the further application in large-scale industry.This dissertation focus on the selective oxidation ofα,β-unsaturated alcohols on heterogeneous catalysts with Pd as active component. The results showed that C=O group formed firstly via dehydrogenation over Pd catalysts. Then, hydrogen transfer and oxidation were carried out as competitive reactions, followed by the formation of saturated ketone and unsaturated ketone, respectively. Pd catalysts presented better activity compared with other transitional metal catalysts. However, the selectivity forα,β-unsaturated ketone was low. Doped with Co, Pd catalysts showed mild reduced activity with increased selectivity. To improve the catalytic performance, cumene hydroperoxide was chosen as additional oxidant and the selectivity ofα,β-unsaturated ketone reached more than 95% under oxygen atmosphere.
|