Effect of different preparation methods on catalytic performance of vanadium-based catalysts for NH3-SCR
Vanadium based catalyst precursors were prepared by blending method,sol gel method and hydrothermal method,respectively,and calcined to get denitration catalyst.The effects of preparation methods and supports on the NH3-SCR performance of vanadium(V)based catalysts were studied.It was found that the VOx/TiO2-BM catalyst prepared by conventional blending method had amorphous active vanadium oxide dispersed in the anatase TiO2 carrier,with over 90% NOx conversion at(200~400)℃.The VOx/CeO2-HT catalyst prepared by hydrothermal method has CeVO4 structure formed by solid solu-tion of the active component V and Ce,and its catalytic activity is only 70%~80% of NOx conversion at(200~400)℃.The VOx/MnOx-HT catalyst is prepared by hydrothermal method,and amorphous active vanadium oxide is dispersed in spinel Mn3O4 support.The NOx conversion of VOx/MnOx-HT at(220~400)℃ is more than 95%.The VOx/MnOx-SG catalyst is prepared by sol-gel method,and amorphous active vanadium oxide is dispersed in spinel Mn3 O4 and Mn2 O3 composite oxide support,and it has high catalytic activity and a wide temperature window with the NOx conversionof more than 95% at(200~420)℃.Besides,VOx/MnOx-SG catalyst exhibits excellent resistance and stability against water vapor and sulfur poisoning.The results indicate that catalysts prepared by different methods have different struc-tures,and support plays an important role in the catalytic performance of the catalyst for NH3-SCR.Moreover,the structure of the support has a significant impact on the activity and stability of the cat-alyst for NH3-SCR.
catalyst engineeringblending methodsol-gel methodhydrothermal methodvanadium-based catalysts for SCRwide temperature window