Highly active NbOPO4 supported Cu-Ce catalyst for NH3-SCR reaction with superior sulfur resistance

In this paper, the Cu-Ce based catalyst using NbOPO 4 (Nb-P) as support was firstly employed for selective catalytic reduction (SCR) of NO by NH 3 . The experimental results had illustrated that such catalyst exhibited well SCR activity and N 2 selectivity within a wide temperature range of 200–450 °C. These superior performances could be mainly attributed to its improved textural properties and strong acidity derived from NbOPO 4 support. More importantly, the sulfur tolerance of the NbOPO 4 supported Cu-Ce sample was found greatly improved compared to TiO 2 and Ti-Nb supported samples, where above 80% SCR activity of Cu-Ce/Nb-P sample was obtained at 250 °C after 10 h reaction running in the presence of 100 ppm SO 2 . This fact was the result of the enhanced acidity and the strong interactions between Cu-Ce oxides and NbOPO 4 support, which could prevent the surface oxygen species from sulfation by SO 2 . As such, these oxygen species strongly associated with NbOPO 4 support still could activate adsorbed NH 3 to fulfill the SCR reaction cycle, leading to its better sulfur resistance. The work would provide some enlightenments to the development of NH 3 -SCR catalysts with high sulfur resistance at medium-high temperature.