Preparation And Evaluation Of DeNOx Catalyst Based On Impregnation Faciliated By Combustible Carrier

Powder and honeycomb NH3-SCR catalysts were prepared in this paper, and both in-situsol-gel method and two-step impregnation method were adopted in the preparation of the powdercatalyst. The two-step impregnation method was optimized by varying the supports and theirstructures, the precursors of active component and the method utilizing combustible carrier. Allcatalysts were characterized with XRD, UV-Vis, in-situ FTIR, SEM, NH3-TPD and H2-TPR todeeply understand the structure, acidity, redox property and reaction mechanism involving inNH3-SCR of NO. The results show that the catalysts made by the in-situ sol-gel method hadmesoporous structure, high dispersion of V2O5on the surface of TiO2and wide window ofworking temperatures, but the method itself is expensive. The two-step impregnation method hasthe feature of low cost, and the prepared V2O5-WO3/TiO2catalyst on mesoporous TiO2allowedalso a wide working-temperature window. Using combustible carrier to facilitate the dispersion ofTiO2support further made the resulting catalyst have activity and performances of denitrationsimilar to that of the catalysts made by the sol-gel method. Then, honeycomb catalyst wasprepared by the extrusion method based on blending clay and the powder catalyst facilitated usinga combustible carrier. Testing the effect of different clays on the preparation process and thehoneycomb catalyst itself found that the catalyst blending70wt.%clay well met the requirementof industrial application for de-NOx of flue gas. A coating honeycomb catalyst was also tested,demonstrating that its activity increased with increasing the coating thickness and the catalyst witha thickness of110?m enabled the comparably good activity as the extruded honeycomb of100%powder catalyst. This indicates thus a possible low-cost technology for making honeycomb.