Exploring the optimal ratio of elemental components of the Cu/SSZ-13 framework: the reformation of NH3-SCR properties

Abstract

This paper mainly studied the influence of the Si/Al ratio on the performance of the Cu/SSZ-13 catalyst synthesized by the ion exchange method. NH₃-SCR experimental results show that the catalyst SAR10 has the best catalytic performance, and it can maintain a 100% conversion rate in the range of 250 °C to 600 °C. Although SAR6 samples with low Si/Al ratios have abundant active centers, their low temperature activity is poor due to their poor crystallinity. The decrease of the number of active sites available for exchange in the SAR25 sample with too high an Si/Al ratio results in a decrease in catalytic activity throughout the temperature range. The results of the in situ DRIFTS experiment show that the order of the number of Lewis acid sites and the content of monodentate nitrate adsorption sites is the same as the order of catalytic activity.