The Studies On The Catalytic Properties Of The Modified CoFe Prussian Blue Analogues

In recent years,due to their unique structural characteristics,metal-organic frameworks?MOFs?have gained rapid emergence and development in the field of materials science.Prussian blue analogues have the similar structure with MOFs and therefore have been applied in many fields such as gas storage and separation,biomedicine,catalysis and magnetism.Epoxy styrene,which is mainly produced by the epoxidation of styrene,is an important organic intermediate,and used in the perfumery and pharmaceutical industry.Recently,Prussian blue analogues used as catalysts have been studied by our laboratory for the epoxidation of styrene to epoxybenzene and the catalytic properties is different.In order to improve the catalytic effect of Prussian blue analogues,the modified Co???Fe???Prussian blue analogues were synthesized and the catalytic properties were studied on the epoxidation of styrene in this paper.Firstly,we synthesized Co???Fe???Prussian blue analogues in various ionic liquids and applied Prussian blue analogues to catalyze the epoxidation of styrene.It is obtained that the enhancements of different kinds of ionic liquids are unequal and the catalytic property of Co???Fe???Prussian blue analogues synthesized in the ionic liquids of 1-butyl-3-methyl imidazole bistrifluoromethanesulfonimide?[BMIM]TF₂N?is the best;In the following experiment,it is found that the effects of this ionic liquids on the catalytic properties of different kinds of Prussian blue analogues are different,some have been improved,while others have decreased.In order to investigate the reasons,the Infrared Spectroscopy?IR?,X-ray diffraction?XRD?,Thermogravimetric?TG?,scanning electron microscope?SEM?,X-ray photoelectron spectroscopy?XPS?,NH₃-Temperature Programmed Desorption?NH₃-TPD?,Energy Dispersive Spectrometer?EDS?,N₂ adsorption desorption and Elemental Analysis?EA?tests were performed on the catalysts.The results show that the Co???Fe???Prussian blue analogues complex synthesized in[BMIM]TF₂N has a smaller particle size and poorer crystallinity,which is more benefit to the catalytic property.The stronger lewis acid of the catalyst also plays an important role in this reaction.Secondly,Co???Fe???Prussian blue analogues/Mo O₃ complex was prepared and catalyzed the epoxidation of styrene.It is got that Co???Fe???Prussian blue analogues/Mo O₃ complex has a much more excellent catalytic effect compared to Co???Fe???Prussian blue analogues.We conducted related tests such as IR,XRD,Transmission Electron Microscope?TEM?,SEM,NH₃-TPD,EDS,Energy Dispersive X-Ray Spectroscopy?EDX?and N₂ adsorption desorption.It is indicated that Co???Fe???Prussian blue analogues/MoO₃ forms a porous structure with a larger specific surface area and the strength of lewis acid is improved,therefore the complex has a better catalytic effect on the epoxidation of styrene.Finally,we synthesized Co???Fe???Prussian blue analogues in the case of coexistence of surfactants of 2-ethylhexylsulfosuccinate?AOT?and ionic liquids of 1-butyl-3-methylimidazolium tetrafluoroborate and also utilized the catalyst for the epoxidation of styrene.It is found that a better catalytic effect was obtained in the presence of surfactant and ionic liquid.Various characterization such as IR,XRD,TEM and TG and N₂ adsorption desorption were performed.It is demonstrated that the morphology of the catalyst is nano-flaky,the crystallinity is correspondingly inferior to that prepared using water as a solvent and the specific surface area is larger,so the catalyst has more excellent catalytic properties.