Ce_2Mo_3O_(12)超微粒子的制备及催化性能

以硝酸铈和钼酸铵为原料 ,采用溶胶 -凝胶法和微波加热技术制备了Ce2 Mo3 O12 超微粒子催化剂 ,使用DTA -TG ,IR ,XRD以及BET比表面测试等表征手段 ,考察了制备条件对复合氧化物超微粒子形成 ,晶相和比表面积的影响 .同时 ,测试了该样品对甲苯选择性氧化制苯甲醛反应的催化性能 .结果表明 :制备Ce2 Mo3 O12 超微粒子的适宜条件为 :初始溶液pH =1.0 ,柠檬酸 / (铈 +钼 )摩尔比等于 0 .4 ,在此条件下制得的干凝胶 ,经微波加热处理后 ,粒子的比表面积为 35 .8m2 /g ,粒径约为 4 0nm .在由甲苯气相选择氧化制苯甲醛的反应中表现出较好的催化活性

Preparation and Catalytic Activity of Ce2Mo3O12 Ultrafine Particle Catalyst

Ce 2Mo 3O 12 ultrafine particle catalyst was prepared from gel precursor on heating in microwave oven. The precursor was obtained from Ce(NO 3) 3 and (NH 4) 6Mo 7O 24 in citric acid .The influences of preparation conditions on the crystal phase and the dimension of the particles were studied using XRD, DTA-TG, IR and BET surface area measurement. The activity and selectivity of the Ce 2Mo 3O 12 catalyst for the selective oxidation of toluene to benzaldehyde was investigated. The results show that appropriate condition is citric acid/ (Ce +Mo) molar ratio = 0.4 and pH = 1.0 for preparing Ce 2Mo 3O 12 ultrafine particle. The BET surface area of the sample treated in microwave oven is 35.8 m 2 / g, with the size of about 40 nm. The catalytic activity of the sample prepared by sol-gel method is higher than that prepared with precipitation method on the selective oxidation of toluene to benzaldehyde.