Effect Of Synthesis Methods And New Carbon Materials On The Catalytic Properties Of The Prussian Blue Analogues

Epoxy phenyl ethane is also called styrene oxide, as synthetic intermediate in perfume industry and pharmaceutical industry, and is also used for epoxy thinners, flavouring agent, etc. Therefore, how to get styrene oxide is getting attention. Most modern industries use the halogen alcohol method for synthesis of styrene oxide, but the energy and material consumption are very big, and the damage and pollution to the environment are serious. Previously, we found Prussian blue analogues can be applied to catalyze the reaction of styrene epoxidation. In this paper, on the basis of the previous studies, we use ionic liquid synthesis method andprepare composite materials with new carbon materials, which are carbon nanotubes and carbon quantum dots, to further improve the catalytic performance of Prussian blue class analogues.First of all, we synthesized CoFe(Ⅲ)PBA in traditional aqueous solution and room temperature ionic liquids(with or without DMF), and used energy dispersive spectrometer(EDS), X-ray diffraction(XRD), infrared absorption(IR), N2-adsorption/desorption, Elemental analysis(EA), Thermal gravimetry(TG),Scanning electron microscopy(SEM), and transmission electron microscopy(TEM) to character their chemical composition, structure and morphology,respectively. At the same time, we applied the above CoFe(Ⅲ)PBAs to catalyze the reaction of styrene epoxidation. The results showed that the CoFe(Ⅲ)PBA synthesized in room temperature ionic liquids and with DMF had smaller particle size, larger specific surface area, and higher catalytic activity.Secondly, we prepared CoFe(Ⅱ) PBA/carbon nanotubes(CNTs) composite materials by ultrasonic method, investigated the chemical composition, structure and morphology of CoFe(Ⅱ)PBA and CoFe(Ⅱ)PBA/CNTs composite by EDS, XRD, IR, SEM and X-ray photoelectron spectroscopy(XPS) and applied them to catalyze the reaction of epoxidation of styrene, respectively. The results indicated that the catalytic activity of CoFe(Ⅱ)PBA/CNTs composite material was superior to those of CoFe(Ⅱ)PBA and carbon nanotubes taken independently, owing to larger surface area and better particle dispersion. Furthermore, kinetic studies of catalytic styrene epoxidation reaction based on these two catalysts were also carried out.Finally, two kinds of CoFe(Ⅲ)PBA@Carbon quantum dots(CQDs) composites with different shell thickness were synthesized by peristaltic pump drops method. Their structures and compositions were confirmed by numerous techniques(XRD, IR N2-adsorption/desorption, TEM, Raman spectroscopy and XPS),respectively. Also, CoFe(Ⅲ)PBA and CoFe(Ⅲ)PBA@CQDs were applied to catalyze the reaction of styrene epoxidation. It was found that CoFe(Ⅲ)PBA@CQDs had higher catalytic activity because of larger specific surface area and the interaction of CQDs and CoFe(Ⅲ)PBA. Among them, catalytic performance of CoFe(Ⅲ)PBA@CQDs-1 with the thinner shell was the best. Additionally, we compared the circulation voltammetry curves of these three kinds of materials, and the results demonstrated the current value of core-shell materials with the thinnest shell is largest.