▎ 摘　　要

Surface functionalization of graphene oxide and magnetite-graphene oxide nanocomposite produced new heterogeneous molybdenum catalysts for the epoxidation of olefins. First, graphene oxide was covalently modified with 3-aminopropyl triethoxysilane and thiophene-2-carbaldehyde to achieve graphene oxide supported bidentate Schiff base ligand. Then, reaction of the supported ligand with MoO2(acac)(2) complex produced heterogeneous molybdenum catalyst. Moreover, a magnetically separable heterogeneous catalyst was prepared by conjugation of the graphene oxide with magnetite nanoparticles through the click reaction and similar modification of the obtained support with molybdenum-Schiff base complex. The second catalyst can be easily recovered with using an external magnet. The prepared catalysts were characterized with various physicochemical methods. Catalytic activities of the obtained catalysts were evaluated in the epoxidation of olefins with test-butylhydroperoxide which showed excellent catalytic efficiencies. The catalysts were consecutively reused five times without loss of their activities.