作者:Daojun Zhang,Ziran Ma,Baodong Wang,Tao Zhu,Duan Weng,Xiaodong Wu,Jingyun Chen,Hongyan Wang,Ge Li,Jiali Zhou
摘要:The effect of manganese and/or ceria loading of V2 O5-MoO3/TiO2 catalysts was investigated for selective catalytic reduction(SCR) of NOx by NH3.The manganese and/or ceria loaded V2 O5-MoO3/TiO2 catalysts we re prepared by the wetness impregnation method.The physicochemical characteristics of the catalysts were thoroughly characterized.The catalytic performance of 1.5 wt% V2 O5-3 wt% MoO3/TiO2(V1.5 Mo3/Ti) is greatly enhanced by addition of 2.5 wt% MnOx and 3.0 wt% CeO2(V1.5 Mo3 Mn2.5 Ce3/Ti) below450℃.Compared with the V1.5 Mo3/Ti catalyst with NOx conversion of 75% at 275 ℃,V1.5 Mo3 Mn2.5 Ce3/Ti exhibits higher NOx conversion of 84% with good resistance to SO2 and H2 O at a gas hourly space velocity value of 150000 h-1.The active manganese,cerium,molybdenum,and vanadium oxide species are highly dispersed on the catalyst surface and some synergistic effects exist among these species.Addition of MnOx significantly enhances the redox ability of the cerium,vanadium,and molybdenum species.Addition of Ce increases the acidity of the catalyst.More active oxygen species,including surface chemisorbed oxygen,form with addition of Mn and/or Ce.Because of the synergistic effects,appropriate proportions of manganese in different valence states exist in the catalysts.In summary,the good redox ability and the strong acidity contribute to the high NH3-SCR activity and N2 selectivity of the V1.5 Mo3 Mn2.5 Ce3/Ti catalyst in a wide temperature range.And the V1.5 Mo3 Mn2.5 Ce3/Ti catalyst shows good resistance to H2 O and SO2 in long-time catalytic testing,which can be ascribed to the highly sulfated species adsorbed on the catalyst.
发文机构:National Institute of Clean-and-Low-Carbon Energy School of Chemical&Environmental Engineering Key Laboratory of Advanced Materials of Ministry of Education
关键词:SelectivecatalyticreductionVANADIUMMolybdenumMANGANESECERIUMRareearths
分类号: X701[环境科学与工程—环境工程]O643.36[理学—物理化学]