Design Of Mn(salen)/NH-PMO Hybrid Catalysts And Their Catalytic Performance

In recent years the research of catalyst is no longer limited to the application of some active component directly acting on some catalytic reactions. As the earth’s environment suffered more and more serious pollution and the deterioration of human survival condition day by day, "Environmental friendly catalyst" gradually aroused people’s attention, This type of catalyst request non-toxic, high efficiency and no pollution in the course of the chemical reaction. The directly application of traditional homogeneous active component as a catalyst in catalytic reactions, it is not only restrict the selectivity of reaction, but also brings a series of problems, for example, reduce the stability of hydrothermal, environmental pollution, toxic, low reaction efficiency and hardly to recycle, etc. Choose a suitable carrier, make the homogeneous active components fixed on it, form the hybridization of heterogeneous catalysts, it is not only can greatly improve the efficiency of catalyst, also can overcome those problems one by one, is definitely an effective method to realize it’s application.In this dissertation, the amino-functionalised periodic mesoporous ethylenesilica(pr-NH2-PMO) and the hybridization catalysts of transition metal based on pr-NH2-PMO have been prepared, which were through simply one step condensation method to achieve the organic functional mesoporous silica, then synthetic the organic-inorganic hybrid catalysts by grafting. To evaluate these two catalytics performance of the resulting materials, selective the Knoevenagel reaction of condensation of benzaldehyde and malononitrile under mild reaction conditions and the epoxidation of olefin are picked out to be model reactions, respectively. Specific contents are as follows:1.Putting the organic-silane bridging reagents as organic silicon precursor, 3-APS(3-aminopropyl trimethoxysilane) as organic functional reagents, Cationic surfactant CTAB(hexadecyltrimethylammonium bromide) as structure-directing agent, An material(pr-NH2-PMO) with ordered mesoporous structure was prepared through one step condensation method in the mixed solution NaOH and NaCl. The composition and structure of as synthesized pr-NH2-PMO material was characterized by 13 C CP-MAS NMR spectra, FT-IR, Low angle XRD, Nitrogen gas porosimetry measurement and TEM and to confirm the structure integrities and investigate the morphology and surface textural properties of the composite catalysts.Using the Knoevenagel reaction of benzaldehyde and malononitrile under mild reaction conditions as the probe reaction. Influences of key reaction parameters, including the amount of catalyst, the effect of solvent, amount of substrate, aminopropyl input amounts and reaction time were likewise considered during the tested catalytic processes. And the reasonable explanation was given according to different response results. Finally, the reusability of the pr-NH2-PMO catalysts was evaluated.2.Using Mn(salen)(chelating schiff base which having four coordination with Mn as it’s center) as active components. Making the atomic of Mn on Mn(salen) and the atomic of N on PMO form the coordination bond by grafting method in alkaline environment, successfully synthesized the aminopropyl group-functionalized pr-NH2-PMO silica hybridization materials with Mn(salen) composite supported, named Mn(salen)/NH-PMO. The structure, and porosity of the resulting composite catalyst was well-characterized by Fourier transform infrared(FT-IR) spectroscopy, inductively coupled plasma atomic emission spectroscopy(ICP-AES), low-angle X-ray diffraction(LXRD) analysis, nitrogen sorption analysis and transmission electron microscopy(TEM).Picking the epoxidation reaction of styrene as model reactions, using aqueous NaClO as the oxidant and PPNO as axial catalyst in the solution of methylene chloride when the temperature was 0 °C. The influences of key reaction parameters, including reaction temperatures, the amount of catalyst, the amount of PPNO and reaction times. And the reasonable explanation was given according to different response results. Finally, the reusability of the catalysts was evaluated.