Lyophilization-based synthesis of HKUST-1 encapsulated molybdenyl acetylacetonate nanocrystals: An effective soybean oil epoxidation catalyst

A novel nanomaterial of MoO2(acac)2 encapsulated in HKUST-1 (MoO2(acac)2@HKUST-1) was conveniently prepared by using the lyophilization method. The material, characterized by several techniques including XRD, N2 physisorption, SEM, FT-IR, XPS UV-Vis DRS and CO-FT-IR, was found to have an enhanced acidity and an additional Lewis acid site different from that in the HKUST-1 crystals. Moreover, the MoO2(acac)2 complexes were uniformly incorporated into the microporous cages of HKUST-1 and the confinement effects provide by the host porous structure significantly decreased the leaching of MoO2(acac)2. As a result, this new catalyst showed efficient catalytic performance and was stable, thus, could be recycled in the epoxidation of soybean oil (SBO) with tert-butyl hydroperoxide (TBHP) as the oxidant in toluene solvent.