Catalytic epoxidation of cyclic alkenes with air over CoOx/zeolite heterogeneous catalysts

•The supported CoOx/zeolite catalysts are prepared by a simple impregnation method.•CoOx/Y exhibits a high activity for the epoxidation of cyclic alkenes with air.•For cyclooctene, 61.2 mol% conversion with 98.8% epoxide selectivity is achieved.•The CoOx/Y catalyst is highly reusable heterogeneous catalyst.

The supported CoOx/zeolites have been prepared and applied for the epoxidation of cyclic alkenes with air. The catalysts are characterized by powder X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–vis) and scanning electron microscope (SEM). Among these CoOx/zeolite catalysts, 2.4% CoOx/Y exhibits the best catalytic activity for the epoxidation of cis-cyclooctene with 61.2 mol% conversion and 98.8 mol% selectivity of epoxide. Some factors such as the kind of zeolites, the oxidants, the solvents, the Co contents, the reaction temperature and time play important roles in controlling the epoxidation. The recyclable stability of the 2.4% CoOx/Y catalyst is confirmed.

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