氧化镁负载磷钼钒杂多酸催化剂的结构和催化性能

Structure and Catalytic Activities of Magnesia Supported Molybdovanadophosphoric Acid Catalysts

采用乙醇溶液中浸渍的方法制备了氧化镁负载的磷钼钒酸铜 (Cu2 PMo1 1 VO40 )催化剂 ,考察了正己醇选择氧化生成正己醛的催化反应性能 .催化剂的 IR,XRD,UV-DRS,NMR,DTA-TG和比表面积等测试结果表明 ,Cu2 PMo1 1 VO40 在氧化镁表面单层分散 ,形成缺位型 Keggin结构 .反应后催化剂表面分散状态及结构未发生明显改变 ,Keggin型对称结构有所恢复 ,形成活化状态的缺位型 Keggin结构 .

MgO supported copper salts of molybdovanadophosphoric acid H 4PMo 11VO 40 catalysts were prepared in alcohol by impregnation, and its catalytic activities for the reaction of n-hexanol conversion towards n-hexanal exhibit a higher selectivity(>93% in all case). Chemical nature and texture of MgO were not damaged in the alcohol impregnation solution. The measurements of IR, XRD, UV-DRS, NMR, DTA-TG and BET surface area showed that the copper salts of molybdovanadophosphoric acid monolayer dispersed on the surface of MgO and the Keggin type structure of the heteropoly acid salts only partly decomposed. It is observed that the Keggin type structure could be renewed after the catalytic reaction, and an activity phase was formed.