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摘要: 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NH3-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、H2-TPR、NH3-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。Abstract: 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.
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Key words:
- NH3-SCR /
- Y-Ce-Mn/ZSM-5 /
- catalyst /
- NOx /
- active temperature /
- denitration efficiency
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图 1 不同金属改性的Ce-Mn/ZSM-5及Ce-Mn/ZSM-5的NOx转化效率
Figure 1 NOx conversion efficiency of the modified Ce-Mn/ZSM-5 catalysts
图 2 不同金属改性的Ce-Mn/ZSM-5及Ce-Mn/ZSM-5的XRD谱图
Figure 2 XRD characterization of different metal modified Ce-Mn/ZSM-5 and Ce-Mn/ZSM-5
图 3 不同金属改性Ce-Mn/ZSM-5催化剂的TEM照片
Figure 3 TEM images of the modified Ce-Mn/ZSM-5 catalysts
(a): Co-Ce-Mn/ZSM-5; (b): Cr-Ce-Mn/ZSM-5; (c): Cu-Ce-Mn/ZSM-5; (d): La-Ce-Mn/ZSM-5; (e): Zr-Ce-Mn/ZSM-5
图 4 不同金属改性的Ce-Mn/ZSM-5催化剂的NH3-TPD谱图
Figure 4 NH3-TPD profiles of the modified Ce-Mn/ZSM-5 catalysts
图 5 不同金属改性的Ce-Mn/ZSM-5催化剂的H2-TPR谱图
Figure 5 H2-TPR profiles of the modified Ce-Mn/ZSM-5 catalysts
图 6 Cu-Ce-Mn/ZSM-5催化剂表面NH3吸附in situ DRIFTS谱图
Figure 6 In situ DRIFTS spectra of the surface NH3 adsorption over the Cu-Ce-Mn/ZSM-5 catalyst
图 7 Cu-Ce-Mn/ZSM-5催化剂饱和吸附NH3后通入NO+O2 in situ DRIFTS谱图
Figure 7 In situ DRIFTS spectra of the Cu-Ce-Mn/ZSM-5 catalyst: NO+O2 injection after saturated adsorption of NH3
图 8 Cu-Ce-Mn/ZSM-5催化剂表面NO+O2吸附in situ DRIFTS谱图
Figure 8 In situ DRIFTS spectra of the Cu-Ce-Mn/ZSM-5 catalyst: NO + O2 adsorption
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