不同金属改性Ce-Mn/ZSM-5催化剂的制备及性能研究

采用浸渍法制备了一系列Y-Ce-Mn/ZSM-5催化剂(Y=Co、Cr、Cu、La、Zr)。结合NH_3-SCR反应脱硝活性测试的结果,获得各种催化剂的最佳活性温度窗口及最大脱硝效率。采用XRD、TEM、H_2-TPR、NH_3-TPD和in situ DRIFTS等技术对催化剂进行了表征。结果表明,除Cr之外,其他改性金属的最大脱硝效率均在98%以上,其中,Cu改性的Cu-Ce-Mn/ZSM-5显示出最佳的催化活性,在375℃转化率达到99.22%。原因在于表面金属氧化物种高度分散,起作用的表面弱酸酸位较多,还原性强的物种量较多。

Preparation and properties of Ce-Mn/ZSM-5 catalysts modified with different metals

A series of Y-Ce-Mn/ZSM-5 catalysts (Y=Co, Cr, Cu, La, Zr) were prepared by impregnation method. Combined with the results of the NH₃-SCR activity test, the optimal activity temperature window and maximum denitration efficiency of various catalysts were obtained. The catalysts were characterized by XRD, TEM, H₂-TPR, NH₃-TPD and in situ DRIFTS. Through the characterization and denitration test, it was shown that the maximum denitration efficiency of all modified catalysts except Cr modified one was higher than 98%, and Cu-Ce-Mn/ZSM-5 showed the best performance among the catalysts, whose catalytic conversion at 375℃ was 99.22%. This is attributed to the highly dispersed surface metal oxide species, more surface sites with weak acidity and more species with high reducibility.