Influence of framework n(Si)/n(Al) ratio on the nature of Cu species in Cu-ZSM-5 for $NH_3-SCR-DeNO_x$

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.