Zhong B.,South China University of Technology |
Zhou G.,South China University of Technology |
Wang W.,South China University of Technology |
Fu M.,South China University of Technology |
And 6 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2011
MnOx catalyst was modified with Fe substitution and the structure properties of composite oxide and reaction pathway of low temperature SCR was investigated by N2 adsorption, XRD, XPS and in situ DRIFTS. The activity was greatly enhanced after the substitution and the highest SCR activity and N2 selectivity was achieved on Fe-Mn mixed oxides with the molar ratio of Fe/(Fe+Mn)=0.3 calcined at 400°C. Amorphous structure was observed resulted from the interaction of Fe and Mn, with Mn enriched on the surface and enhanced mobile lattice oxygen, leading to better redox properties. The in situ DRIFTS results indicated that the addition of Fe contributed to the activation of adsorbed NH3 species and maintained the adsorption of NO in the high activity NO- form. Therefore, a fast and reversible redox process between the adsorbed species developed on the catalyst surface, resulting in remarkable enhancement of the NOx conversion.