Liquid phase trans-stilbene epoxidation over catalytically active cobalt substituted TUD-1 mesoporous materials (Co-TUD-1) using molecular oxygen

A series of framework substituted Co-TUD-1 catalysts, prepared by direct hydrothermal synthesis, were characterized using X-ray diffraction, nitrogen physisorption, transmission electron microscopy and UV-vis and Raman spectroscopies. These catalysts showed high conversion and selectivity towards trans-stilbene oxide in liquid phase trans-stilbene epoxidation with molecular oxygen as oxidant in the absence of a sacrificial reductant. The conversion and selectivity did not remarkably differentiate for fresh and recycled catalyst after four reaction runs. The unique pore structure of Co-TUD-1 catalyst is suggested to be beneficial for the epoxidation of bulky alkene molecules comparing with other well-established catalysts, e.g., Co-MCM-41 and Co²⁺-NaX. Microwave irradiation can significantly shorten the reaction time, whereas high conversion and epoxide selectivity remained.