Denitration performance of HoCeMn/TiO2 catalysts prepared by co-precipitation and impregnation methods
Impregnation and co-precipitation methods were used to synthesize HoCeMn/TiO2 catalysts for the reduc-tion of NOx with NH3.Different kinds of characterization methods were used to explore the structures and perfor-mances of the catalysts.The results show that the co-precipitation method enhances the interactivity between the active component and carrier,thereby increasing the content of Ce3+,Mn4+,and adsorption oxygen on the surface of HoCeMnTi-C.As a result,it showed excellent low-temperature redox performance.In addition,HoCeMnTi-C pre-pared by the co-precipitation method possessed more surface acidic sites and stronger surface acidity.The improve-ment of surface acidity and redox performance is conducive to the adsorption and activation of ammonia,and there-by significantly improved its activity.The increase of acidic sites also restrained the adsorption of H2O and SO2,and therefore sulfur and water resistance of HoCeMnTi-C were significantly promoted.The reaction of selective catalytic reduction(SCR)on catalysts obeys the Eley-Rideal(E-R)mechanism.SO2 poisoning of catalysts was caused by the formation of sulfates,which cover or damage the active sites of the catalysts.
HoCeMn/TiO2 catalystactivitywater and sulfur resistance
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