Simultaneous removal of Hg0 and NO in simulated flue gas on transition metal oxide M' (M' = Fe2O3, MnO2, and WO3) doping on V2O5/ZrO2-CeO2 catalysts

Abstract

The additive effect of different transition metal oxide M' (M' = Fe2O3, MnO2, and WO3) doping on V2O5/ZrO2–CeO2 (V/ZrCe) catalyst with reduced vanadium for simultaneous removal of NO and Hg0 was investigated. V/ZrCe doped with Fe2O3, MnO2, and WO3 and reduced vanadium were prepared by a wet-impregnation method and tested for their catalytic activity of simultaneous removal of NO and Hg0 in the temperature range of 100–400 °C. A combination of various analytical techniques including SEM, BET, XRD, H2-TPR and XPS were used to characterize the characteristics of catalysts. Results indicated that the introduction of M' could enhance the catalytic properties of the catalysts. V0.01Mn/ZrCe and V0.01Fe/ZrCe catalyst presented higher activities than the V0.03/ZrCe catalyst below 250 °C, while V0.01W/ZrCe catalyst exhibited a higher performance in the temperature range of 300–400 °C. The transition metal oxide M' species exist in a well dispersed state on V0.01/ZrCe catalysts. Doping the transition metal oxide M' on V0.01/ZrCe could affect the oxidation state of vanadium oxide and cerium oxide via the reaction of V4++Ce4+↔V5++Ce3+. Besides, the NO conversion was little impacted by Hg0, whereas SCR atmosphere has inhibited on Hg0 oxidation due to the strong competitive adsorption of NH3 with Hg0. The water and sulfur resistance performance decreased in the order of V0.01W/ZrCe> V0.01Fe/ZrCe > V0.01Mn/ZrCe.