共沉淀法掺杂SiO2对V2O5-WO3/TiO2催化剂SCR性能的影响  

Influence of SiO_2-doped V_2O_5-WO_3/TiO_2 Catalysts by Co-precipitation Method on SCR Performance

作　　者：赵梦梦[1] 陈梦寅 张鹏举[1] 赵辉[1] 唐富顺[1] 阮乐[1] 杨宏斌[1,2] 

机构地区：[1]桂林理工大学化学与生物工程学院,桂林理工大学广西有色金属隐伏矿床勘查及材料开发协同创新中心,广西桂林541004 [2]广西壮族自治区固体废物管理中心,广西南宁530028

出　　处：《分子催化》2017年第3期223-235,共13页Journal of Molecular Catalysis(China)

基　　金：广西自然科学基金项目(No.2014GXNSFAA118057);广西科学研究与技术开发计划项目(No.1598007-39)~~

摘　　要：通过共沉淀法将SiO_2组分掺入到V2O5-WO3/SiO_2-TiO_2催化剂TiO_2载体中,并通过多种物理化学手段,考察了不同SiO_2掺杂量对催化剂结构、表面性质与SCR性能的影响.结果表明,SiO_2掺入到TiO_2中,Si与Ti形成Si—O—Ti键,使催化剂比表面积增加.Si—O—Ti键的生成以及Si Ox物种上的-OH基团使催化剂表面Br?nsted酸增加,但新增的Br?nsted酸对SCR反应不利,并且SiO_2的掺杂也使得V^(5+)含量降低,Si—O—V键合作用使分散的VOx物种更难还原.Si组分以共沉淀法掺入到V_2O_5-WO_3/TiO_2催化剂会造成脱硝活性的显著下降.SiO2 components were doped into TiO2 carrier of V2O5-WO3/TiO2 catalysts by co-precipitation and the effect of SiO2 content on the structure, dispersed species and SCR performance of the catalyst were investigated by various physical and chemical methods. XRD and BET results showed that SiO2 can interact with TiO2 through Si—O—Ti bond which increased BET surface areas of catalysts. NH3-DRIFTS, NH3-TPD, H2-TPR, XPS and UV-vis DRS results showed that Si—O—Ti bond and-OH species on SiOx can increase the amount of Br？nsted acid, but the newly-increased Br？nsted acid was unfavorable for the SCR reaction. Also, doping of SiO2 decreased V5＋ content and Si—O—V bond can reduce the reducibility of VOx species. Therefore, SiO2 doping into V2O5-WO3/TiO2 catalysts by co-precipitation method can result in a significant decrease of the SCR activity.

关 键 词：SiTiOx复合氧化物 V2O5-WO3/TIO2催化剂 掺杂 SCR VOx物种 

分 类 号：TF823[冶金工程—有色金属冶金] O643.3[理学—物理化学]