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

Abstract

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 NH3 (NH3-SCR). The Co-Cr layered double oxide catalyst exhibits the improved catalytic performance for NH3-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 NOx removal efficiency in the NH3-SCR. In the presence of SO2, the Co-Cr layered double oxide catalyst was sulfated and chromium sulfate species was formed. The sulfate Co-Cr layered structure catalyst showed higher NOx conversions than the fresh catalyst with a high SO2 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 NH3-SCR reaction.