The Ce doping Cu/ZSM-5 as a new superior catalyst to remove NO from diesel engine exhaust

• The addition of Ce has strong promoting effect on SCR activity over Cu/ZSM-5.
• The Ce doping greatly enhances the hydrothermal stability of Cu/ZSM-5.
• The introduction of Ce stabilizes the dispersion of CuO and suppresses the bulk-type CuO crystallites formation.
• The resistance to SO2 is greatly enhanced for Ce modified Cu/ZSM-5.

The Ce doping Cu/ZSM-5 catalysts were prepared using an improved incipient-wetness-impregnation method, and their catalytic performances were tested for the selective catalytic reduction (SCR) of NO with NH3. The aim of the present study was to understand and elucidate the deNOx activity as well as deactivation behaviors of the Ce doping Cu/ZSM-5 catalyst. The catalysts were characterized by a series of analytical techniques, including XRD, NH3-TPD, TEM, XPS, and TGA. The results indicated that the well dispersion of CuO nanoparticles was the primary cause for the high deNOx performance of the Ce doping Cu/ZSM-5 catalyst. The addition of Ce greatly improved the hydrothermal stability of the Cu/ZSM-5 catalyst, due to it could stabilize the dispersion of CuO and suppress the bulk-type CuO crystallites formation during hydrothermal treatment. The inhibition of deposition of CuSO4 by doping of Ce made the Cu/ZSM-5 catalyst a good resistance to SO2. In conclusion, the catalytic performance, hydrothermal stability and SO2 resistance of the Cu/ZSM-5 catalyst were greatly improved by the addition of Ce, which made the Ce doping Cu/ZSM-5 as a promising catalyst for the NH3-SCR technology.