The Catalysis Research Of Epoxidation Of Carbon-Carb-on Unsaturated Double Bond By Heteropoly Compounds

Epoxides[]are[]valuable[]organic[]raw[]materials[]and[]intermediates[]for[]fine[]chemical[]andpharmaceutical[]synthesis. However, the traditional epoxidation processes (Haakon andepichlorohydrin) have caused serious environmental pollution and other problems on anindustrial scale. Therefore, various[]environment-friendly[]and[]efficient[]green[]epoxidationcatalysts[]have[]been[]investigated. It[]is[]recently[]recognized[]that[]the[]combination[]of[]organicspecies[]with[]heteropolyacids (HPAs)[]may[]cause the[]formation[]of[]organic-HPA[]hybridwith[]diverse[]chemical[]structures[]and[]thus improve its catalytic[]behaviors. On the otherhand, Ionic[]liquids (ILs) have[]been[]revealed[]as[]green[]reaction[]media[]with[]the[]propertiesbeing flexibly adjusted by various cations and anions. The combination of IL cations withHPA anions has[]been[]investigated[]recently[]as[]a[]new[]research[]respect. From[]the[]molecularlevel, this thesis designs and prepares the ILs-based HPA hybrid catalysts by the combinationof functionalized IL cations and heteropolyanions,[]and[]explores[]their[]catalytic[]performancefor[]epoxidation[]with[]H2O2.The[]following[]is[]the[]main[]results.(1) A organic-HPA hybrid CmAMn–PW was prepared by anion-change of [PO4(WO3)4]3with[]amide[]structure[]ionic[]liquids,[]further[]characterization[]was[]conducted[]by[]FT-IR,[]TG,1H[]NMR[]and[]CHN[]Elemental[]analyses. Their catalytic behaviors were evaluated inepoxidation[]reactions,[]including[]the testing[]of[]influence[]of organic cations, optimization[]ofreaction[]conditions.[]These[]catalysts[]proved[]to[]be[]high[]catalytic[]activity[]homogeneouscatalysts. In particular, for the catalyst C12AM12–PW modified by the dodecyl amide cation,the[]conversion[]of[]cyclohexene[]and selectivity for epoxycyclohexane were96.8%and80.1%.For the catalyst C16AM16–PW, the conversion of soyben oil (SBO) and selectivity forepoxidized soyben oil (ESO) were98.4%and50.1%.(2) Peroxopolyoxotungsten-based hybrid catalysts modified by dicationic long-chainalkyl imidazolium cations which have been synthesized and further characterization wasconducted by FT-IR, TG,1H NMR and CHN Elemental analyses. These catalysts proved tobe high catalytic activity phase transfer catalysts. In particular, for the catalyst[D12mim]1.5PW4O24modified by the dodecyl dicationic imidazolium cation, the conversionof cyclohexene and selectivity for epoxycyclohexane were97.7%and96.3%. For the catalyst[D16mim]1.5PW4O24, he conversion of SBO and selectivity for ESO were97.0%and82.4%.After the reaction, the catalyst could be recovered simply by filtration and reused. Inaddition, this phase transfer catalyst can be applied to the epoxidation of a wide rangeof olefins and unsaturated fat oils.(3) A novel amphiphilic POM-paired ionic copolymer DIM-CIM-PW was prepared bythe anion-exchange of a newly task-specific designed functionalized-ionic liquid copolymerwith H3PW4O16, and characterized. The[]new[]catalyst[]exhibits[]high[]catalytic[]activity[]andselectivity[]in[]catalyzing[]epoxidation of alkenes, plus the advantages of convenient recoveryand steady reusability. The peroxo-tungstate species in PW anions act as the active centresfor epoxidation reactions, while the amphiphilic catalyst structure as a―trapping agent‖.