MnxCe1-xO2／γ-Al2O3催化剂的制备及其催化甲苯的燃烧性能

Preparation of Mn_xCe_(1-x)O_2/γ-Al_2O_3 catalysts and catalytic combustion of toluene

以γ-Al2O3为载体,以MnxCe1-xO2为催化活性组分,采用浸渍法制备了一系列负载型MnxCe1-xO2/γ-Al2O3催化剂(x=0、0.2、0.4、0.6、0.8、0.9、1),在固定床反应器中评价了催化剂对甲苯的催化燃烧性能。结果表明,MnxCe1-xO2/γ-Al2O3催化剂的催化活性与催化剂的焙烧温度、活性组分MnxCe1-xO2的负载量以及Mn、Ce摩尔比有显著关系,其中焙烧温度550℃、负载量为20%、Mn、Ce摩尔比为4∶1时,即Mn0.8Ce0.2/γ-Al2O3催化剂对甲苯的催化性能最佳,反应温度为180℃时,甲苯的转化率达到95%。并在连续100 h的稳定性操作后,催化剂的活性基本无变化。采用XRD、BET以及SEM等分析测试手段对催化剂的结构以及表面进行了表征。

A series of MnxCe1-xO2/γ-Al2O3 catalysts with different molar ratios of Mn to Ce were prepared by impregnation. Toluene was chosen as the model compound to evaluate the catalysts in a conventional fixed-bed quartz reactor. The results show that catalytic activity was dependent on catalyst calcination temperature, the content of active component MnxCe1-xO2 and the molar ratio of Mn to Ce. 20% MnxCe1-xO2/γ-Al2O3 catalyst at calcinations temperature of 550℃ exhibited the highest activity for catalytic oxidation of toluene. The conversion rate was 95% at 180℃ , without losing activity during the 100 h activity test. The structure and surface of the catalysts were characterized using X-ray diffraction（XRD） , BET and scanning electron microscopy （SEM）.