title: Zirconium phenylphosphonate-anchored methyltrioxorhenium as novel heterogeneous catalyst for epoxidation of cyclohexene.
abstract: Epoxidation of olefins to epoxides is widely recognized as an important unit process in the manufacture of fine chemicals and intermediates. Developing an environmentally benign heterogeneous catalytic system for olefin epoxidation with high activity and selectivity is still a challenge in this research field. Herein, we report our attempts to synthesize novel zirconium phenylphosphonate-anchored methyltrioxorhenium (MTO/ZrPP) heterogeneous catalysts by a conventional impregnation method and evaluate their catalytic performance for epoxidation of cyclohexene using urea-hydrogen peroxide adduct (UHP) as oxidant without the addition of base ligands. The MTO/ZrPP catalyst samples are characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), inductively coupled plasma emission spectrometry (ICP-ES), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and solid-state (1)H magic-angle spinning nuclear magnetic resonance ((1)H MAS NMR) techniques. Meanwhile, the density functional theory (DFT) calculation is carried out to further understand the structure feature and interactions of the MTO/ZrPP catalyst. It is revealed that MTO is anchored on support surface by the favored hydrogen-bonding interaction between two oxo ligands of MTO and two H atoms from the adjacent phenyls of ZrPP. MTO/ZrPP catalyst displays excellent catalytic activity for cyclohexene epoxidation. Moreover, only cyclohexene oxide production can be obtained under the employed reaction conditions.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Sha
authors.initials: S
authors.lastname: He
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Hongyue
authors.initials: H
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: zhangfz@mail.buct.edu.cn.
authors.forename: Fazhi
authors.initials: F
authors.lastname: Zhang
mesh_terms: D002384:Catalysis; D053138:Cyclohexenes / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D009942:Organometallic Compounds / Q000737:chemistry*; D063065:Organophosphonates / Q000737:chemistry*; D033362:Powder Diffraction; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D053138:Cyclohexenes; D004852:Epoxy Compounds; D009942:Organometallic Compounds; D063065:Organophosphonates; C052568:cyclohexene; C411866:methyltrioxorhenium VII
keywords: Density functional theory; Epoxidation of cyclohexene; Metal phosphates and phosphonates; Methyltrioxorhenium