异丁烯选择氧化制备甲基丙烯醛催化反应的研究

采用共沉淀法制备催化剂，考察了催化剂制备过程中浆液的pH值和焙烧温度以及反应过程中原料的水蒸气比例和反应压力对复合氧化物催化剂催化异丁烯选择氧化生成甲基丙烯醛反应性能的影响。采用SEM和XPS方法对催化剂的物理化学性质进行了表征。结果表明：在pH=3.0条件下制备的催化剂异丁烯的转化率要明显高于在pH=1.0和pH=6.0条件下制备的催化剂。焙烧温度为400℃的催化剂异丁烯的转化率最高，焙烧温度为500℃的催化剂甲基丙烯醛的选择性最高。加水可以提高异丁烯转化率和甲基丙烯醛选择性，而加压可提高异丁烯转化率，但降低甲基丙烯醛的选择性。

Studies on catalytic reaction of selective oxidation of isobutylene to methacrolein

The catalysts were prepared by the method of the co-precipitation. The catalytic performance for selective oxidation of isobutylene to methacrolein was studied by the pH value of solution and calcination temperature during the preparation of catalysts, the content of the vapor in the material and the pressure of reaction during the process of reaction. The physico-chemical properties of the catalysts were characterized by SEM and XPS. The experimental results indicated that: The conversion of isobutylene with the catalyst of pH=3.0 was obvious higher than that with catalyst of pH=1.0 and pH=6.0.The catalyst on calcination temperature of 400℃ had the highest conversion of isobutylene and the catalyst on calcination temperature of 500℃ had the highest selectivity of methacrolein .With the increase of the vapour content the conversion of the isobutylene and the selectivity of the methacrolein improved, enhancing the pressure increased the conversion of the isobutylene simultaneously decreased the selectivity of the methacrolein.