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8648307 
Journal Article 
Effect of Mn Content on Denitration and SO2 Oxidation Performance of Mn/ZSM-5 Catalyst 
Xiao, H; Li, J; Jiang, Y; Li, X; Dou, C; Han, G 
2021 
Chk 
Huanjing Kexue Yanjiu / Research of Environmental Sciences
ISSN: 1001-6929 
34 
2 
272-278 
Chinese 
The effects of Mn content on the SO2 oxidation characteristics of Mn-based catalysts was evaluated by preparing a series of Mn/ZSM-5 catalysts with different Mn content using a wet impregnation method. The SO2 oxidation and denitration properties and the physicochemical parameters of these catalysts were examined employing various characterization techniques. The results showed that: (1) During the standard SCR reaction, increasing the Mn content and the initial temperature increased the SO2 oxidation rate to a maximum value at 300 ℃, above which the rate decreased. (2) During the fast SCR reaction, NO2 directly oxidized SO2, so this compound increased the SO2 oxidation rate. At 300 ℃, SO2 oxidation reached the highest (0.76%). (3) The NOx conversion rate initially increased and then decreased with increasing temperature. During the fast SCR reaction, the presence of NO2 promoted the redox reaction, and the 9Mn (the mass fraction of Mn loading is 9%) catalyst exhibited the highest NOx conversion rate (96.58%) at 250 ℃, which is much higher than the NOx conversion rate of the standard SCR reaction. (4) Increasing the Mn loading increased both the lattice oxygen and the Mn4+ concentrations in the material, leading to an increase in the SO2 oxidation rate and NOx conversion rate. However, excessive Mn loading was determined to promote the accumulation of active materials on the catalyst surface while reducing the lattice oxygen and Mn4+ levels. These changes in turn reduced the redox performance of the Mn-based catalyst. In the actual operating temperature range of 150-400 ℃, a Mn-based supported catalyst should be carefully formulated to ensure high denitration efficiency while minimizing the SO2 oxidation rate. © 2021, Editorial Board, Research of Environmental Sciences. All right reserved. 
Denitration performance; Fast SCR reaction; Manganese-based catalyst; SO2 oxidation rate