WO_3对V_2O_5/TiO_2-ZrO_2催化剂NH_3-SCR脱硝的影响  

Influence of WO_3 Doping on Properties of V_2O_5/TiO_2-ZrO_2 Catalysts for Selective Catalytic Reduction of NO_x by NH_3

作　　者：徐海涛[1] 朱一闻[1] 张亚平[1] 王龙飞[1] 赵英杰[1] 金保昇[1] 

机构地区：[1]东南大学能源与环境学院能源热转换及其过程测控教育部重点实验室,江苏南京210096

出　　处：《环境科学与技术》2017年第1期5-10,共6页Environmental Science & Technology

基　　金：国家自然科学基金项目(51306034);江苏省重点研发计划项目(BE2015677);国家重点基础研究发展计划项目(2013CB228505)

摘　　要：采用共沉淀法制备TiO_2-ZrO_2固溶体浸渍法负载WO_3和V_2O_5得到一系列V_2O_5-(x%)WO_3/TiO_2-ZrO_2催化剂。利用比表面积测定(BET)、X射线衍射(XRD)、原位漫反射傅里叶变换红外光谱(In situ DRIFTS)、程序升温脱附(NH_3-TPD)、高分辨率透射电子显微镜(HRTEM)等表征技术,结合脱硝性能测试,研究催化剂的表面特性、微观结构及脱硝活性;同时针对优选出的脱硝性能较好的催化剂,研究SO_2和H_2O对其活性的影响。结果表明:WO_3的负载增强了催化剂孔隙结构的稳定性和Lewis酸的强度。当WO_3含量为9%时,催化剂的孔隙结构最稳定,表面-NH_2活性物种最多,NH_3的吸附量最大脱硝活性最高,在300~400℃的温度窗口平均保持在92%以上。而当烟气中同时含有SO_2和H_2O时,催化剂活性会显著下降,且中毒不可逆。TiO2-ZrO2 solid solution was prepared by a co-precipitation method and V2O5-（x%）WO3/TiO2-ZrO2 catalysts were prepared using the impregnation method.The physicochemical properties were investigated by X-ray diffraction（XRD）,BET specific surface area,NH3 temperature-programmed desorption（NH3-TPD）,in situ diffuse reflectance infrared Fourier transform spectroscopy（in situ DRIFTS） and high-resolution transmission electron microscopy（HRTEM）.Their catalytic performance for the selective catalytic reduction of NOx was tested,as well as the effect of SO2 and H2O on SCR catalytic activity for the preferred catalysts.It was found that the strength of Lewis acid sites and the stability of the pore structure are increased with the load of WO3.The results of catalytic activity indicated that the catalyst with 9%WO3 content exhibits 92%NO conversion within the wide temperature range of 300 ℃ to 400 ℃ due to the most stable pore structure,the most active species-NH2 on the surface and the biggest absorbing capacity of NH3.When SO2 and H2O get into the flue gas,the SCR catalytic activity sharply decreases and it is an irreversible process.

关 键 词：WO3 V2O5 TiO2-ZrO2固溶体 SCR脱硝 SO2和H2O中毒 

分 类 号：X701.7[环境科学与工程—环境工程]