钒钛催化剂制备工艺对表面结构与催化分解气相二噁英的影响  

Effect of preparation processes of vanadium-titanium catalysts on catalytic decomposition of gaseous dioxins

作　　者：向辉[1] 王朵[1] 唐爱东[1] 何曦[2] 杨华明[2] 柯轲[1] 

机构地区：[1]中南大学化学化工学院 [2]中南大学资源生物学院无机材料系,长沙410083

出　　处：《中国科技论文在线》2011年第3期220-225,共6页

基　　金：国家科技支撑计划资助项目(2008BAC32B05);中南大学大学生创新性实验计划(LD09163)

摘　　要：研究了V2O5/TiO2催化剂的制备工艺,如载钒量、煅烧时间、助催化剂和浸渍次数等对催化分解二噁英模型物邻二氯苯的影响。采用漫反射紫外光谱(DRUV)、X射线衍射光谱(XRD)、BET等手段对催化剂进行了表征。结果表明,随着钒负载量增大,催化剂表面活性物质含量增多,催化性能增强;延长煅烧时间有利于生成低聚态活性钒,但也会导致团聚增加,比表面积减小;添加助剂WO3和采用多次浸渍均能抑制活性钒的团聚,促进表面低聚态活性钒的分散;DRUV进一步研究表明,单聚和低聚钒酸盐是VOx/TiO2催化剂的活性物质,而高聚钒对催化分解气相邻二氯苯有抑制作用。The effects of preparation processes of vanadium-titanium catalysts such as vanadium content,calcinations time,additive and the number of impregnation times on catalytic decomposition of o-dichlorobenzene as a model of dioxins have been studied.The catalysts were characterized by means of diffuse reflectance UV spectroscopy（DRUV）,X-ray diffraction spectrum（XRD） and the BET technique.The results showed that the active sites on the surface of the catalysts increased with V loading increased and the catalytic performance was enhanced.Prolonged calcination time was beneficial to produce oligomeric active vanadium,but induced the aggregation of vanadium and decreased the specific surface area.Tungstic oxide additive and multiple impregnation method were both beneficial to generate welldispersed active vanadium and inhibit the aggregation and polymerization of surface vanadium.The further results of DRUV indicated that monomer and oligomeric vanadate were the active sites of VOx/TiO2 catalysts and polymeric vanadium has a negative role on the catalytic decomposition of o-dichlorobenzene.

关 键 词：钒钛催化剂 制备 催化分解 二噁英 

分 类 号：X701[环境科学与工程—环境工程]