| The Keggin-type of heteropoly acids(HPA)and its ramification is a kind of catalyst which has the pseud-liquid characteristic of redox and acidity.At the same time,it has following differential function:easily synthesizing,low cost,good thermal stability,and redox and acidity can be controlled in molecular level by changing compositive elements.In recent years,it has been investigated extensively in the catalytic field and the material chemistry.The Keggin-type heteropoly acids of phase-transfer catalyst has been synthesized by reaction of tetra-n-butylammonium bromide and HPAs,and characterized by Infrared Ray spectroscopy and 31PNMR.These datas indicated that they had the Keggin structure.In the base of literatures,we researched double-functional properties of Keggin-type HPC catalytic systems.The main content as following:(l)These catalysts were used in styrene oxidation to benzaldehyde using 30%H2O2 as oxidant by used the double-functional properties of Keggin structure compounds.The reaction conditions such as catalyst,solvent, reaction time,and temperature were investigated.The products were analysed by GC-MS and its mechanism was studied.At last,we acquired the optimal reaction conditions.In this system,The salt[(C4H9)4N]3PMo12O40is the the best catalyst of oxidation of styrene.The catalyst system which Keggin-type heteropoly acids of phase-transfer as catalyst and H2O2 as oxidant is base of oxidation of styrene.(2)The oxidation of benzaldehyde to benzoic acid first used ethanoic acid as medium and 30%hydrogen peroxide as oxidant under the mild condition, investigating the effects of different conditions to reaction.It was found that the components of the catalyst have high activity in the oxidation reaction compared to single component.Moreover,the experimental procedure is quite simple,convenient and the product has high purity.The catalyst could be reused three times without detectable loss of activity.
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