F掺杂改性及其制备方法优化对V_2O_5-WO_3/TiO_2催化剂低温SCR脱硝性能的影响  

Influence of F-doping modification and preparation method optimization of V_2O_5-WO_3/TiO_2 catalyst on its NO reduction at low temperature

作　　者：崔晶 黄华存 董文华 安学文 CUI Jing;HUANG Huacun;DONG Wenhua;AN Xuewen(School of Resource,Environment and Materials,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学资源环境与材料学院,南宁530004

出　　处：《环境工程学报》2018年第11期3139-3152,共14页Chinese Journal of Environmental Engineering

基　　金：广西大学博士启动项目(XBZ170344)

摘　　要：为提高SCR脱硝催化剂的低温脱硝性能,采用正交实验的方法制备了一系列氟(F)掺杂V_2O_5-WO_3/TiO_2催化剂,并对其进行活性分析,考察了不同氟元素来源(氟钛酸铵、氟化铵)、不同钒元素(V)前驱体(乙酰丙酮氧钒、偏钒酸铵)、钨元素(W)的不同添加方式(W做助剂、W既做载体又充当助剂)、不同载体制备方式(溶胶凝胶法、浸渍法)对催化剂脱硝性能的影响。结果表明,F掺杂改性显著增强了催化剂在200～350℃温度范围内的脱硝性能,其中以乙酰丙酮氧钒为V前驱体,以氟化铵为F源,W既充当载体又做助剂的方式制备出的F掺杂V_2O_5-WO_3/TiO_2催化剂具有最优的脱硝效果,其在空速为10 000 h-1的情况下,在200～350℃的温度反应区间,活性能稳定维持在98%以上。同时采用XPS、BET、TGA、SEM、XRD、Raman一系列表征手段对催化剂的理化性质进行了分析,表征结果表明F元素掺杂提高了活性组分在载体表面的分散度,同时促使了催化剂表面的电荷发生转移,增强了催化剂表面的氧化还原能力,促进了催化剂表面化学吸附氧的生成,增加了还原态V物种与还原态W物种的数量。To improve the denitration performance of the SCR catalyst at low temperature,a series of F doped V2O5-WO3/TiO2catalysts were prepared by orthogonal test and their catalytic activity for denitration were analyzed.The effects of vanadium precursors,flourine sources,tungsten addition ways and carrier preparation methods on the denitration performance of the catalysts were studied.The results indicated that the F-doping modification method could greatly enhanced the denitration performance of the catalyst at the temperature ranging from 200℃to 350℃.When the F doped V2O5-WO3/TiO2catalyst was prepared by using vanadium acetylacetone as V precursor,ammonium fluoride as F source and W as carrier,it presented the best denitration performance,its denitration rate was higher than 98%at the 10 000 h（-1）space velocity and the reactive temperature range from 200℃to 350℃.Meanwhile,the identification by XPS,BET,TGA,SEM,XRD,Raman test showed that F doping improved the dispersion of the active component on the surface of the carrier,promoted the charge transfer on the surface of the catalyst,and strengthened the REDOX capacity on the surface of the catalyst.Then the formation chemisorbed oxygen on the catalyst surface was faciliated,and the reductive species of V/W increased accordingly.

关 键 词：选择性催化还原(SCR) F掺杂改性 V2O5-WO3/TIO2催化剂 低温SCR脱硝 

分 类 号：X701[环境科学与工程—环境工程]