选择性氧化制备甲基丙烯醛催化剂及工艺条件优化

Preparation of catalyst for selective oxidation to methylacrolein and process condition optimization

采用共沉淀法制备Mo-V-Bi系复合氧化物催化剂,并将其应用于叔丁醇选择性氧化制甲基丙烯醛反应。采用XRD及BET考察焙烧温度对催化剂性能的影响。结果表明,焙烧温度会影响催化剂的比表面积和孔结构,进而影响催化剂性能。低温焙烧的催化剂会形成一种Mo O3的物相,这种物相会抑制产物甲基丙烯醛选择性,而高温有利于催化剂Fe Mo O4、Bi Mo O6物相的生成,两物相的增加有利于提高甲基丙烯醛选择性。对筛选的最优催化剂进行长周期评价,叔丁醇转化率接近100%,甲基丙烯醛选择性为87.1%,达到了良好的工业效果。

The composite oxides of Mo-V-Bi were synthesized by precipitation method and applied in partial oxidation of isobutylene to methacrolein（ MAL）. Effects of calcination temperature of catalysts were studied by XRD and BET. It was found that calcination temperatures affected performance of the catalyst by adjusting specific surface area and pore structure of the catalyst. Mo O3 phase formed at low calcinations temperature calcination could decrease selectivity of MAL. Fe Mo O4 and Bi Mo O6 phases formed at high calcination temperature could improve selectivity of MAL. Long-term running of optimized catalyst shows that tertiary butyl alcohol conversion is about 100% and selectivity of MAL is 87. 1%. The catalyst could satisfy industrial requirements effectively.