A contrastive study of the introduction of cobalt as a modifier for active components and supports of catalysts for NH3-SCR

Abstract

Three catalysts Mn/Ce–ZrOX, Mn–Co/Ce–ZrOX and Mn/Co–Ce–ZrOX were used for low-temperature NH3-SCR of NO. XRD, TPR and XPS were performed to characterize the physicochemical property of the catalysts. Experimental results showed that Mn/Co–Ce–ZrOX had a higher dispersion of manganese oxides, a better redox property, more surface acid sites and more surface adsorbed oxygen species and Mn4+ ion. These facts caused a better low-temperature activity for Mn/Co–Ce–ZrOX which was 99.0% at 180°C. Furthermore, Mn/Co–Ce–ZrOX showed the best resistance to SO2 and H2O which mainly because the introduction of cobalt inhibited the formation of sulfate salts and hydroxyls on the surface of Mn/Co–Ce–ZrOX.