Improving catalytic performance with sulfur resistance over Co-Cr layered double oxide for low temperature NH3-SCR

• Co-Cr layered double oxides were used as effective catalyst for NH 3 -SCR. • Co 2 Cr 1 O x -LDO catalyst showed a high catalytic activity and H 2 O-SO 2 resistance. • Improved texture and surface chemical properties could lead to catalytic activity. • Sulfated Co 2 Cr 1 O x -LDO catalyst also showed high activity and SO 2 resistance. In this study, a series of Co-Cr layered double oxide catalysts are prepared and used for low temperature selective catalytic reduction of NO by NH 3 (NH 3 -SCR). The Co-Cr layered double oxide catalyst exhibits the improved catalytic performance for NH 3 -SCR with a better tolerance against sulfur compounds in the feed stream. The unique structural property, surface acidity, redox ability, increased structure distortion and Cr reduction properties of Co-Cr layered double oxide catalysts were responsible for the improved NO x removal efficiency in the NH 3 -SCR. In the presence of SO 2 , the Co-Cr layered double oxide catalyst was sulfated and chromium sulfate species was formed. The sulfate Co-Cr layered structure catalyst showed higher NO x conversions than the fresh catalyst with a high SO 2 resistance caused by an improvement of acidity. The enhanced catalytic activity and sulfur tolerance should suggest that the Co-Cr layered double oxide catalyst could be used as an effective catalyst for low temperature NH 3 -SCR reaction.