ZSM-5 core–shell structured catalyst for enhancing low-temperature NH3-SCR efficiency and poisoning resistance

By constructing core–shell ZSM-5@CeO 2 support rather than bulk phase for loading copper, the enhanced NH 3 -SCR performance as well as H 2 O and SO 2 tolerance was achieved. Cu/(ZSM-5@CeO 2 ) catalyst exhibited the superior activity with the lowest T 90 at 215 °C, which is due to the interaction between CeO 2 shell and copper ions that promotes the redox properties as evidenced by oxygen isotopic exchange technique. The ZSM-5 core provides more acid sites to improve the ammonia adsorption. Thus, the highest activity of Cu/(ZSM-5@CeO 2 ) catalyst can be ascribed to the synergistic effect of redox ability and acidity. The CeO 2 shell can react with SO 2 preferentially and lead to a high sulfur tolerance. This study provides a strategy for design and the practical applications of NH 3 -SCR zeolite catalysts. • Cu/(ZSM-5@CeO 2 ) catalyst exhibits excellent FRESH NH 3 -SCR activity. • Synergistic of CeO 2 shell and copper ions promote redox ability. • CeO 2 shell produce more oxygen vacancies and effectively improve the oxygen mobility. • CeO 2 shell prefers to react with SO 2 and accordingly protect the copper ions.