Influence of framework n(Si)/n(Al) ratio on the nature of Cu species in Cu-ZSM-5 for $NH_3-SCR-DeNO_x$
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These data relate to IR studies on nanosized Cu-containing ZSM-5 catalysts with different n(Si)/n(Al) ratios of 18.9–50.5. According to DR UV-Vis, TPR-H2, EPR, or FT-IR spectroscopy analyses, the amount of aggregated copper species increases with increasing the framework n(Si)/n(Al) ratio. The catalytic potential of the materials studied was evaluated in NH3-SCR-DeNOx process. The activity of the Cu-containing ZSM-5 with n(Si)/n(Al) ratio of 47.0—50.5 in the selective catalytic NO reduction with NH3 (NH3-SCR-DeNOx) significantly decreases compared to the other materials (n(Si)/n(Al) ratio of 18.9—19.6). The reaction mechanism has been discussed in light of the results of 2D COS (two-dimensional correlation spectroscopy) analysis of IR spectra and catalytic properties of the zeolites. The results make evident that enhanced activity of Cu-containing ZSM-5 in NH3-SCR-DeNOx is correlated with the formation of different NOx− under the experimental conditions.
本数据集围绕硅铝摩尔比(n(Si)/n(Al))为18.9~50.5的不同规格纳米级含铜ZSM-5分子筛催化剂的红外光谱(Infrared, IR)研究展开。借助漫反射紫外-可见光谱(Diffuse Reflectance Ultraviolet-Visible Spectroscopy, DR UV-Vis)、氢气程序升温还原(Temperature Programmed Reduction-Hydrogen, TPR-H2)、电子顺磁共振波谱(Electron Paramagnetic Resonance, EPR)以及傅里叶变换红外光谱(Fourier Transform Infrared, FT-IR)等表征手段分析可知,团聚态铜物种的含量随分子筛骨架硅铝摩尔比的升高而增加。本研究通过氨选择性催化还原脱硝(NH3-SCR-DeNOx)反应评价了所制备材料的催化性能:硅铝摩尔比为47.0~50.5的含铜ZSM-5分子筛在该反应中的催化活性,相较于硅铝摩尔比为18.9~19.6的其余样品出现了显著下降。本研究结合红外光谱的二维相关光谱(Two-Dimensional Correlation Spectroscopy, 2D COS)分析结果与分子筛的催化性能,对该反应的机理进行了探讨。研究结果表明,含铜ZSM-5分子筛在氨选择性催化还原脱硝反应中提升的催化活性,与实验条件下不同NOx−物种的生成密切相关。



