Performances of Mn-Ce-Zr/γ-Al2O3 catalyst for low temperature selective catalytic reduction of NO

The Mn-Ce-Zr/γ-Al2O3 catalyst with high selective catalytic reduction (SCR) activity at low temperature was prepared by the sol-gel method. The NO conversion reaches 70% at 150℃ and then increases to 95% at 250~300#x02103;. The catalyst can also be well-behaved under high space velocity and in the presence of SO2 and H2O. NH3 and NO oxidation performance was tested on the fixed bed. It shows that NH3 can be oxidized to NO at high temperature, while NO is easy to be oxidized to NO2 at 250~300℃, which is beneficial for the proceeding of SCR reactions. Several characterization methods, such as N2 adsorption-desorption, X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR) and temperature programmed desorption (TPD) were adopted. It shows that Zr can be incorporated into the CeO2 crystal lattice and form the solid solution, resulting that the BET surface area and pore volume of this catalyst increases obviously. The results of TPD indicate that NH3 is mainly adsorbed on the weak acid sites, and NO can be adsorbed as the nitrite, unstable and stable nitrate species, which is in favor of the low-temperature SCR reaction proceedings. © 2015 Chin. Soc. for Elec. Eng.