Phosphotungstic acid supported on magnetic nanoparticles as an efficient reusable catalyst for epoxidation of alkenes

A new magnetically separable catalyst consisting of phosphotungstic acid supported on imidazole functionalized silica coated cobalt ferrite nanoparticles was prepared. The synthesized catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). This immobilized phosphotungstic acid was shown to be an efficient heterogeneous catalyst for the epoxidation of various alkenes using tert-butylhydroperoxide (t-BuOOH) as oxidant. The catalyst is readily recovered by simple magnetic decantation and can be recycled several times with no significant loss of catalytic activity.

Figure optionsDownload as PowerPoint slideHighlights
► Phosphotungstic acid supported on functionalized cobalt ferrite was prepared.
► Silica coated cobalt ferrite nanoparticles were used as support.
► This composite was successfully used as catalyst for epoxidation of alkenes.
► Oxidation reactions were carried out in the presence of t-BuOOH as oxidant.
► The catalyst can be readily separated from solution by magnetic field.