Abstract: A series of Dawsontype vanadiumsubstituted heteropoly acids was synthesized successfully. These compounds show an excellent activit y for the oxidation of cyclohexane with 30% H₂O₂ as oxidant. The reaction conditions, such as the number of the vanadium atom substituted in the heteropolya cids, amount of the catalyst, temperature, amount of H₂O₂ and reaction time were investigated in detail. The research results reveal that Dawsontype m olybdovanadophosphoric heteropolyacids exhibit better activities for the oxidation of cyclohexane compareable to Keggintype molybdovanadophosphoric heteropolyacids.

Key words: Dawsontype molybdovanadophosphoric heteropoly acid, cyclohexane, oxidation