Cr-Ce/TiO_2低温催化还原NO性能研究  

Low-Temperature Catalytic Reduction of NO over Cr-Ce/TiO_2 Catalyst

作　　者：罗晶[1] 童华[2] 童志权[1] 黄妍[1] 李慧洁[1] 

机构地区：[1]湘潭大学环境工程系,湖南湘潭411105 [2]北京化工大学环境工程系,北京100029

出　　处：《石油化工》2010年第9期1046-1051,共6页Petrochemical Technology

基　　金：湖南省自然科学基金资助项目(07JJ4003)

摘　　要：用浸渍法制备了Cr-Ce/TiO2催化剂,考察了焙烧温度、活性组分配比和负载量对催化剂低温NH3选择性催化还原NO活性的影响,并对催化剂进行了XRD和BET表征,得到了催化剂的最佳制备条件;探讨了H2O和SO2对Cr-Ce/TiO2催化剂活性的影响,通过FTIR表征分析了催化剂的中毒机理。实验结果表明,n(Cr)∶n(Ce)=2.0、Cr2O3和CeO2负载量(质量分数)为30%、350℃焙烧的Cr-Ce/TiO2催化剂具有良好的分散性,在气态空速10 000h-1、气体体积组成为NO0.080%,O26.000%,NH30.088%的条件下,反应温度为180℃时NO转化率高达99.6%。体积分数10%的H2O对该催化剂的活性影响很小;反应气中存在体积分数0.03%SO2的情况下,催化剂被毒化,表面生成(NH4)2SO4、NH4HSO4、金属硫酸盐和亚硫酸盐,致使催化活性降低。该催化剂有望应用于基本不含SO2的燃气锅炉烟气和不含SO2的硝酸尾气等NOx工业废气的低温脱硝。Cr2O3-CeO2/TiO2 catalysts were prepared through impregnation method and used in selective catalytic reduction of NO with NH（3） at low-temperature.Effects of calcination temperature,（n（Cr）∶n（Ce）） and loading of active component（Cr2O（3） and CeO2） on the catalyst activity were investigated.The catalysts were characterized by means of XRD and BET to obtain the optimal preparation condition.Effects of H2O and SO2 on the catalyst activity in the reduction were analyzed by means of FTIR.The catalyst calcined at 350 ℃ with total loading 30%（mass fraction） and（n（Cr）∶n（Ce）） 2.0 showed favorable dispersity of the active components on the support.A high NO conversion of 99.6% over the catalyst was observed under the conditions of temperature 180 ℃,GHSV 10 000 h～（-1） and feed gas composition φ（NO） 0.080%,φ（O2） 6.000%,φ（NH3） 0.088%.Effect of 10%（φ） H2O on the catalyst activity was little but negative effect of 0.03%（φ）SO2 in the feed gas on the catalyst was evident due to formation of sulfates and sulfites on the catalyst.The catalyst could be applied to removal of NO（x） from exhaust gas without SO2 at low temperature.

关 键 词：低温选择性催化还原 铬-铈/二氧化钛催化剂 一氧化氮 氨 

分 类 号：TQ426.82[化学工程]