Improve the Hydrothermal Stability of Cu-SSZ-13 Zeolite Catalyst by Loading a Small Amount of Ce

Copper-ion-exchanged SSZ-13 has been demonstrated to be an effective catalyst for the ammonia selective catalytic reduction of NOx. However, the Cu-SSZ-13 is still susceptible to hydrothermal degradation, which reduces the catalyst lifetime. We herein report that the hydrothermal stability of Cu-SSZ-13 can be remarkably enhanced through loading with a small amount of cerium. To clearly reveal the enhancement effect of cerium, we focused on an aluminum-rich Cu-SSZ-13 zeolite (Si/Al ratio: 6.5) with copper loadings ranging from ca. 3.4% to 4.1%, which was found to give high hydrothermal stability while still suffering from considerable degradation upon severe hydrothermal aging. Different cerium loadings were investigated, and a cerium loading with a limited range of ca. 0.2–0.4 wt % resulted in the best enhancement. The introduction of only a small amount of cerium was beneficial because it enabled a high copper loading and abundant Bronsted acidity sites that are needed for high SCR activities over a broa...