Abstract: | A new epoxidation catalyst has been prepared by grafting a molybdenum(VI)–oxodiperoxo complex containing an oxazine ligand, [MoO(O2)2(phox)], on chloro‐functionalized Fe3O4 nanoparticles. The synthesized heterogeneous catalyst (MoO(O2)2(phox)/Fe3O4 was characterized using powder X‐ray diffraction, scanning and transmission electron microscopies, vibrating sample magnetometry, energy‐dispersive X‐ray analysis, Fourier transform infrared spectroscopy and inductively coupled plasma atomic emission spectroscopy. The immobilized complex gave high product yields and high selectivity for epoxide compared to the corresponding homogeneous one in the epoxidation of various olefins in the presence of tert ‐butyl hydroperoxide at 95°C without any co‐solvent. Also, the heterogeneous catalyst can be recycled without a noticeable change in activity and selectivity. |