Abstract:

The MnO _x /ZrO₂ catalyst was prepared by the equal volume impregnation method with commercial ZrO₂ as carrier, and the catalytic ozone degradation effect of the target pollutant methyl orange solution was studied. The factors of calcination temperature and MnO _x loading content were studied to determine the optimal catalyst preparation condition. It turned out that, the catalyst would get the best catalytic activity with 15% MnO _x loading and being calcined at 400℃, and the decolorization efficiency of methyl orange was 92.8% over the catalyst of 15%MnO _x /ZrO₂ (400℃), which increased by 36.1% compared with that in the ozonation without catalyst after 60 min of reaction. Also, the initial pH of methyl orange solution (pH =2.7,6.5,8.7,10.8) was investigated during the catalytic ozonation process. The 15%MnO _x /ZrO₂ (400℃) catalyst performed a higher catalytic efficiency of 95% at pH=2.7 than that value of 6.5 without adjustment by acid or alkali. The catalyst cycle test showed a better stability for 15%MnO _x /ZrO₂ (400℃), and the decolorization rate of methyl orange slightly drop down to about 85% after three times reuse. Moreover，the loss of MnO _x was an important reason for the descent of catalyst activity by characterization experiments.

Key words: incipient wetness impregnation method, catalyst, methyl orange, catalytic ozonation, decolorization reaction

摘要：

以商品化ZrO₂为载体，采用等体积浸渍法制备MnO _x /ZrO₂催化剂，对目标污染物甲基橙溶液进行催化臭氧降解效果研究。比较不同焙烧温度（350、400、500和550℃）、不同MnO _x 负载量（5%、10%、15%和18%）等制备条件对催化剂活性的影响，结果表明：在400℃，MnO _x 负载量为15%时，催化剂对催化臭氧降解甲基橙溶液表现出最好的活性。反应进行60 min后，甲基橙溶液的脱色率达92.8%，较单独臭氧氧化提高了36.1%。催化剂15%MnO _x /ZrO₂（400℃）的酸碱使用范围（pH为2.7、6.5、8.7、10.8）实验表明：甲基橙溶液不同初始pH条件同样会影响催化剂的活性，且pH=2.7时表现出最好的催化效果，甲基橙脱色率可达95%。循环实验表明，15%MnO _x /ZrO₂（400℃）具有较好的稳定性，催化剂循环使用三次后，甲基橙溶液脱色率仍保持在85%以上，且活性组分的流失是降低催化剂活性的一个重要原因。

关键词: 等体积浸渍法, 催化剂, 甲基橙, 催化臭氧氧化, 脱色反应