Catalytic activity of Cu–SSZ‐13 prepared with different methods for NH 3 ‐SCR reaction

Abstract A series of Cu–SSZ‐13 catalysts with the same Cu loading were prepared by different methods of incipient wetness impregnation [Cu–SSZ‐13 (IWI)], ion exchange [Cu–SSZ‐13 (IE)] and hydro‐thermal synthesis [Cu–SSZ‐13 (HTS)]. Their activity for selective catalytic reduction of nitrogen oxides (NO x ) with NH 3 was determined. The results show that the Cu–SSZ‐13(HTS) catalyst exhibits a better ammonia selective catalytic reduction (NH 3 ‐SCR) activity compared with the other two catalysts, over which more than 90% NO conversion is obtained at 215–600 °C under the space velocity of 180,000 h −1 . The characterization results reveal that the Cu–SSZ‐13(HTS) catalyst possesses more amount of stable Cu 2+ in the six‐membered ring and high ability for NH 3 and NO adsorption, leading to its high NH 3 ‐SCR activity, although this catalyst has low surface area. On the other hand, the activity of Cu–SSZ‐13(IE) catalyst is almost the same as that of Cu–SSZ‐13 (IWI) catalyst at the temperature lower than 400 °C, but the activity of the former is much higher than that of the latter at > 400 °C due to the high activity of Cu–SSZ‐13(IWI) catalyst for NH 3 oxidation.