M-Na-P-Mo-V/SiO_2系列催化剂对异丁烯氧化反应的催化性能  

Catalytic Performance of M-Na-P-Mo-V/SiO_2 Series Catalysts for Isobutylene Oxidation

作　　者：蔡铁军[1] 陈亚中[1] 彭振山[1] 龙云飞[1] 蒋绍亮[1] 邓谦[1] 

机构地区：[1]湘潭师范学院化学化工系,湖南湘潭411201

出　　处：《催化学报》2002年第3期285-288,共4页

基　　金：湖南省自然科学基金 (0 1JJY2 0 14 );湖南省教育厅资助项目

摘　　要：以浸渍法制备了M Na P Mo V/SiO2 系列催化剂 ,并用FT IR和TPR对催化剂进行了表征 ,考察了催化剂上的异丁烯氧化反应 .结果表明 ,在空速 90 0h-1和 345℃的反应条件下 ,过渡金属的引入可提高甲基丙烯醛的选择性 .其中Cu对催化剂性能的改善最佳 ,甲基丙烯醛选择性可达 6 5 7% ;而在Na P Mo V/SiO2 催化剂上 ,乙酸选择性可达 5 0 % ,但甲基丙烯醛选择性仅为 4 1% .在催化剂中引入过渡金属时 ,Cu在提高甲基丙烯醛选择性的同时 ,也抑制了完全氧化产物COx 的生成 ;Fe在提高双键断裂产物和完全氧化产物选择性的同时 ,使甲基丙烯醛选择性下降 ;Zn对反应的影响不很大 .TPR结果表明 ,在引入Cu的催化剂中 ,Cu与杂多酸阴离子之间可能存在“溢流”M-Na-P-Mo-V/SiO2 series catalysts were prepared by impregnation method, and characterized by FTIR and TPR. The isubutylene oxidation on the catalysts was carried out in a continuous flow fixed-bed reactor. The results indicated that, owing to the addition of transition metal ions into the catalysts, there is a decrement in activity to a certain extent, but the main products change from acetic acid to methacrolein. The performance of Cu-Na-P-Mo-V/SiO2 catalyst is remarkably improved, providing with selectivity of 65.7% methacrolein and 10.8% acetic acid, while over Na-P-Mo-V/SiO2 catalyst, the selectivity for acetic acid is as high as 50%. The Cu-Na-P-Mo-V/SiO2 inhibits the total oxidation products, the Fe-Na-P-Mo-V/SiO2 catalyst enhances the selectivity for total fission products, and the Zn-Na-P-Mo-V/SiO2 catalyst has only a little effect on the reaction. TPR experiment showed that the interaction of Cu and heteropoly ions made up the active oxidation-reduction centers which corresponds to the reaction results. There may be a 'spillover' phenomenon between Cu and heteropoly ions.

关 键 词：催化性能 钠 磷 钼 钒 过渡金属 二氧化硅 负载型催化剂 异丁烯 氧化 杂多化合物 

分 类 号：O643.3[理学—物理化学]