Anderson型和Waugh型杂多阴离子的电子结构及其催化性能研究

Studies on Electronic Structure and Catalytic Properties of Anderson and Waugh Heteropoly Anions

使用ＳＣＣ－ＤＶ－Ｘα法研究了两种杂多阴离子──（ＩＭｏ_６Ｏ_（２４））^（５－）（Ａｎｄｅｒｓｏｎ型）和（ＮｉＭｏ_９Ｏ_（３２））^（６－）（Ｗａｕｇｈ型）的电子结构，并探讨了它们的催化性能。结果表明，两类杂多阴离子均具有催化活性，但不如Ｋｅｇｇｉｎ结构强，（ＩＭｏ_６Ｏ_（２４））^（５－）的催化活性中心是端氧Ｏ_ｔ和中心八面体氧Ｏ_ｃ。（ＮｉＭｏ_９Ｏ_（２４））^（６－）的催化活性中心是一配位端氧Ｏ_ｔ、四配位中心氧和中心杂原子Ｎｉ，两类杂多阴离子中，二配位桥氧均不作为催化活性中心．

The electronic structures of two heteropoly anions,(IMo6O(24))(5-)(Anderson-type)and(NiMo9O(32))(6-)(Waugh-type),were calculated by SCC-DV-Xαmethod,and the catalytic properties were investigated.The results indicated that both kinds of heteropoly anions can be used as catalysts.The active centers are Ot(terminal oxygen),Oc(links I and Mo)for(IMo6O(24))(5-),and Ot,Ni,Oc(links Ni and three Mo atoms) for(NiMo9O(32))(6-). But bridge oxygen(Ob)is not active, which is different from that of the Keggin-type.