The Polymetallic Oxygen Sour Salt Synthesis And Catalytic Performance Study

Polyoxometallates(heteropolyacids) have been widely employed as oxidation catalysts in various homogeneous and heterogeneous reactions. One of the great advantages of polyoxometallates catalysts is that their oxidation catalytic properties can be controlled in a systematic way by changing the identity of charge compensating counter-cations heteroatoms, and framework polyatoms. However, there are some problems for polyoxometallates in the application, ashomogeneous catalyst, it is difficult to recover the catalyst from the system and as heterogeneous catalyst, their surface area is very low. So it is very important to resolve above mentioned problems for the application of polyoxometallates.Based on the investigation of literatures, this thesis was focused on the research of some organic reactions catalyzed by Keggin type multicomponent HPC catalytic systems. The main progress and research results have been obtained as follows:1. Phosphorus vanadium molybdenum heteropoly acid salt of Keggin type was synthetized through experiment and characterized by FT-IR, XRD and so on. The catalyst performance of catalyst was investigated based on aldolization of benzaldehyde and ethylene glycol. The resulits showed that catalyst had good selectivity and activity under condition that the dosage of benzene was0.2mol, the ratio of ethylene glycol and benzaldehyde was1.6:1, the dosage of catalyst was0.2g, reaction temperature was110℃and the reaction time was120min.2. In allusion to solution problem between catalyst and carrier, the YH6P2Mo15V3O62heteropolyacid was immobilized on concave-convex rod and modified attapulgite. Through modification, the activity of catalyst was highly dispersed in carrier surface. The catalyst performance of catalyst was investigated based on aldolization of benzaldehyde and ethylene glycol. The resulits showed that catalyst had good selectivity and activity under condition that the dosage of benzene was0.2mol, the ratio of ethylene glycol and benzaldehyde was1.6:1, the dosage of cyclohexane was12mL, the dosage of catalyst was0.2g, reaction temperature was110℃and the reaction time was120min. And it could reused many times.3. Oxidation of alcohols with hydrogen peroxide catalyzed by a reusable trilacunary keggin Polyoxometalates.