Influence of Vanadium’s Substitution of Keggin-type Heteropoly Anions on Their Electronic Structures and Catalytic Properties

The electronic structures or （PMo₆V₆O₄₀）^9- have been calculated by SCC-DV-X_α method.Compared with the calculated results of （PMo₁₀V₂O₄₀）^5- and （PMo₁₂O₄₀）^3- we conclude that vanadium’s substitution can affect the electronic structure and catalytic properties of Keggin-type heteropoly anions. The thermal stability and oxidation ability decrease and the catalytic activity increases with the increasing of the number of vanadium atoms. In （PMo₁₂O₄₀）^n-（M =Mo,V）, M, P, O_t（terminal oxygen）, O_b（bridgcd oxygen） have the potential to participate in the catalytic reactions. When the number of vanadium atoms increases vanadium and oxygen which is linked with vanadium will be more active in catalytic reactions, which confirms that （VO₂）^＋ is the active species that has been reported by experiments.