Post-synthesis of hierarchically structured Ti-β zeolites and their epoxidation catalytic performance

Hierarchically structured Ti-β zeolites were prepared using a two-step post-synthesis approach. The physicochemical properties of the resultant Ti-mβ-Sx materials were determined using various techniques, including X-ray diffraction, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, transmission electron microscopy, and ultraviolet-visible and ultraviolet-Raman spectroscopies. The porous structures of the synthesized hierarchical Ti-β zeolites were well preserved. Their catalytic performance was compared with that of pure microporous Ti-β materials using alkene epoxidation as a model reaction. It was found that although comparable catalytic activities were obtained for both types of catalyst in the epoxidation of small molecules, e.g., cyclohexene, the synthesized hierarchical Ti-β gave an enhanced catalytic performance in the epoxidation of bulky 1-dodecene.