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

Abstract By constructing core–shell ZSM-5@CeO2 support rather than bulk phase for loading copper, the enhanced NH3-SCR performance as well as H2O and SO2 tolerance was achieved. Cu/(ZSM-5@CeO2) catalyst exhibited the superior activity with the lowest T90 at 215 °C, which is due to the interaction between CeO2 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@CeO2) catalyst can be ascribed to the synergistic effect of redox ability and acidity. The CeO2 shell can react with SO2 preferentially and lead to a high sulfur tolerance. This study provides a strategy for design and the practical applications of NH3-SCR zeolite catalysts.