Construction of core–shell structure Cu-SSZ-13 catalyst for boosting its NH3-SCR activity and hydrothermal stability

Abstract

Ammonia selective catalytic reduction (NH₃-SCR) of NO is an effective technology for NO_x removal. Catalysts with core–shell structured materials, which exhibit outstanding catalytic performance, have been widely applied in the NH₃-SCR reaction. In this work, core–shell catalysts with Al rich Cu-SSZ-13 as the core phase and Si-rich SSZ-13 as the shell phase were synthesized by a self-assembly method. The effect of the core–shell structure on the hydrothermal stability and catalytic performance of the prepared catalysts in the NH₃-SCR of NO was investigated. The results show that catalysts with a core/shell ratio of 0.2 exhibit better low temperature NH₃-SCR activity and hydrothermal stability. The high silica SSZ-13 shell phase protected the Cu²⁺ active sites in the core phase from the high-temperature water vapor, thus improving the hydrothermal stability of the catalyst.