A novel Nb–Ce/WOx–TiO2 catalyst with high NH3-SCR activity and stability

A novel Nb–Ce/WOx–TiO2 (NbCe/WTi) catalyst was synthesized by impregnating Ce and Nb salts on WO3–TiO2 powders, which exhibits over 80% NOx conversion at 200–500 °C. NbCe/WTi catalyst owns higher hydrothermal stability and alkali poisoning resistance than V2O5–WO3–TiO2 (VWT). Moreover, the sulfated catalyst can be feasibly regenerated by treatment in air at 650 °C. Ceria exhibits superior redox ability of the catalyst and dispersed NbOx and WOx species provide large amounts of acid sites, facilitating the SCR performance at low and high temperatures.

The promotion effects of Nb and Ce on WOx–TiO2 ensure high NH3–SCR performance of the catalyst.Figure optionsDownload as PowerPoint slideHighlights
► Excellent NH3-SCR activity of Nb–Ce/WOx–TiO2 catalyst in a wide temperature range
► Extreme durability to hydrothermal aging
► The sulfated catalyst is feasibly regenerated by calcination in air at 650 °C.
► Highly dispersed NbOx species increase the surface acidity of Ce/WOx–TiO2 catalyst.
► CeO2 promotes the formation of amide in SCR reaction with providing active oxygen.