Preparation And Applications Of Keggin Polyoxometalates Catalytical Materials

Heteropoly compounds have great utilities in catalysis because of their acidity and oxidation-reduction quality. In the work, three P-Mo-V heteropoly acids with different Vanadium number have been synthesized by acidification- etherization. Their component and structure have been confirmed by ICP-AES and TGA. They have been characterized by FT IR, XRD and UV. FT IR demonstrates their Keggin structure. The results of XRD show that they are isomorphism. UV spectra display their similarity of properties.Considering outstanding properties of heteropoly acids, ODA/(PMo10V2O40)5- LB film has been prepared using octadecylamine hydrochloride(ODA). Its morphology and structure have been characterized by AFM, LAXD, FT IR and UV. Its electrochemical behavior was studied by Cyclic voltammetry. All of the results prove the ODA/(PMo10V2O40)5- LB film is steady in structure and properties and well-define between layers. The PMo10V2O405- anion distributes homogeneously in layers. There are sufficient space and channel in layers permitting the heteropoly anion to land the area of electrode and carry out the reaction of electrochemistry. And prove this is the process of two electron with two proton.To explore their catalytical capability, the esterification of phenyl formate and 1-butanol was chosen. It is found that the esterification yield exceeds 80%, which demonstrates the heteropoly acid has higher catalytic activity. In the same time, the catalytic activity of the quaternary ammonium of H5PMo10O40 was studied, too. The results of experiment display it has the capacity of catalytic oxidation. But due to the alkyl in quaternary ammonium isn't long enough, the effect of phase transfer is not very well.Taking account of the environmental protect and many applications, the synthesis and characterization of the polycation, [AlO4(OH)24(H2O)12]7+ has been studied simply.