不同反荷离子的Keggin结构钼磷酸盐的热稳定性及其对异丁醛催化氧化活性的影响

Thermal Stability and Activity of Catalytic Oxidation of Isobutyraldehyde of Molybdophosphoric Salt with Keggin Structure Containing Different Equilibrium Cations

用共沉淀法制备了以Ｋｅｇｇｉｎ结构为骨架的不同反荷离子钼磷酸盐，利用ＦＴＩＲ、ＸＲＤ等手段进行了表征。结果表明，Ｌｉ、Ｎａ、Ｋ、Ｃｓ分别作为反荷离子时的杂多酸盐的热稳定性依次增强，并考察了催化剂对异丁醛一步氧化制甲基丙烯酸的催化活性，其中Ｃｓ盐的催化活性最优。

Molybdophosphoric acid with Keggin structure is an effective catalyst for oxidation reactions. As the central atom, coordinated atom and equilibrium atom in the molydophosphoric acid are displaced in a suitable manner, it exhibits increasing catalytic properties although the structure of the anion keeps unchanging, In this paper a series of Keggin molybdophosphoric acids containing different equilibrium cations were synthesized by a coprecipitation method.The prepared samples were characterized by means of FTIR, XRD and other techniques. Particularly the thermal stability of Li(Na,K, Cs)equilibrium molybdophosphoric salts were investigated. The catalytic acitivity over this series of samplers for one-step oxidation of isobutyraldehyde to produce methacrolic acid was measured as well.The experimental results indicate that Cs+ equilibrium molybdophosphoric salts is the best catalyst for the mentioned reaction.