The modification of Ag/Al2O3 catalyst and application of combined catalysts in methanol-SCR of NO

In this paper, a series of Wx/Ag/Al2O3 catalysts with different tungsten contents (0, 0.04, 0.06, 0.08, and 0.10g/g) and 0.03g/g silver for selective catalytic reduction of NO with methanol under excess oxygen (methanol-SCR), were prepared with a traditional impregnation method. At a gas hourly space velocity (GHSV) of 30000h-1, the operating window of NO conversion (NO conversion above 50%) shifted to a higher temperature region as the tungsten content increased. Importantly, the operating window of NO conversion over combined catalysts containing W8/Ag/Al2O3 in the front and Ag/Al2O3 in the rear (W8/Ag/Al2O3+Ag/Al2O3), was wider (65°C) than that of the single W8/Ag/Al2O3 catalyst (50°C) or Ag/Al2O3 catalyst (41°C). Further, the CO concentration over the combined catalyst was lower than the single W8/Ag/Al2O3 catalyst. The characterization results demonstrated that there are strong interactions between tungsten and silver which contribute to the formation and stabilization of oxidized silver species.

Duke Scholars

Author Li Lan Molecular Genetics and Microbiology