CoCr_2O_4/SiO_2催化剂上二氯甲烷催化氧化

采用浸渍法制备了不同CoCr_2O_4负载量x CoCr_2O_4/SiO_2催化剂(x=5%、10%、20%和30%),考察其对二氯甲烷催化燃烧性能的影响。结果表明,催化剂的整体活性顺序为:30CoCr_2O_4/SiO_220CoCr_2O_4/SiO_210CoCr_2O_4/SiO_25CoCr_2O_4/SiO_2,但按照活性组分CoCr_2O_4质量归一化后本征活性顺序为:10CoCr_2O_4/SiO_2≈5CoCr_2O_4/SiO_220CoCr_2O_4/SiO_230CoCr_2O_4/SiO_2。表征结果发现催化剂本征活性与可还原性能和表面酸性存在密切关系。10CoCr_2O_4/SiO_2和5CoCr_2O_4/SiO_2具有较高的表面酸性和耗氢量,因此具有较高的本征活性。

Catalytic combustion of dichloromethane over CoCr2O4/SiO2 catalysts

Supported xCoCr₂O₄/SiO₂ catalysts with different contents of CoCr₂O₄(x=5%,10%,20%and 30%) were prepared by impregnation method and tested for catalytic combustion of dichloromethane. The results showed that the overall activities of the catalysts followed the order of 30CoCr₂O₄/SiO₂>20CoCr₂O₄/SiO₂>10CoCr₂O₄/SiO₂>5CoCr₂O₄/SiO₂,but the intrinsic activities based on the CoCr₂O4mass normalized content followed the order of 10CoCr₂O₄/SiO₂≈5CoCr₂O₄/SiO₂>20CoCr₂O₄/SiO₂>30CoCr₂O₄/SiO₂.Characterization results revealed that the intrinsic activity of the catalysts was closely related to its reducibility and surface acidity.Compared with the other two catalysts,the 10CoCr₂O₄/SiO₂ and 5CoCr₂O₄/SiO₂ had higher surface acidity and higher surface Cr ion density,therefore have higher intrinsic activity.