整体式V_2O_5-WO_3/TiO_2-ZrO_2催化剂用于NH_3选择性催化还原NO_x  

Selective catalytic reduction of NO_x with NH_3 over V_2O_5-WO_3/TiO_2-ZrO_2 monolith catalysts

作　　者：李鹏[1] 张亚平[1] 肖睿[1] 沈凯[1] 孙克勤[1] 徐海涛[1] 周长城[1] 

机构地区：[1]东南大学能源与环境学院,江苏南京210096

出　　处：《中南大学学报（自然科学版）》2013年第4期1719-1726,共8页Journal of Central South University:Science and Technology

基　　金：国家高技术研究发展计划("863"计划)项目(2007AA061802);江苏省自然科学基金重点资助项目(BK2008001)

摘　　要：通过共沉淀法制备不同锆掺杂量的钛锆复合载体,用分步浸渍法先后浸渍WO3和V2O5得到一系列V2O5-WO3/TiO2-ZrO2催化剂样品,采用X线衍射(XRD)、比表面积测定(BET)、高分辨率透射电子显微镜(HRTEM),程序升温还原(TPR)等表征技术进行相关的表征分析,同时在模拟氨气选择性催化还原NOx(NH3-SCR)的反应条件下对催化剂的脱硝反应活性进行考察。研究结果表明:ZrO2含量为50%(摩尔分数)的催化剂具有较好的热稳定性和较宽的活性窗口。模拟烟气中含有0.08%(体积分数)的SO2时,SO2对所研究催化剂的NO脱除具有一定的促进作用。复合载体Ti0.5Zr0.5O2呈无定形态,具有较大的比表面积和孔容,微粒大小均匀,表面分散性良好;WO3和V2O5高度分散在载体的表面;ZrO2的掺入有利于提高催化剂的还原性能。TiO2-ZrO2 binary oxides with various compositions were synthesized by a co-precipitation method and were impregnated with WO3 and V205 to prepare series of V2Os-WO3/TiO2-ZrO2 catalysts. These catalysts were characterized by using a combination of X-ray diffraction （XRD）, BET surface area, High-Resolution Transmission Electron Microscope （HRTEM）, temperature preprogrammed reduction （TPR）. Their catalytic performance for the selective catalytic reduction of NO with NH3（NH3-SCR） was investigated. The results show that 50% ZrO2 （molar ratio） doped catalyst exhibits excellent stability at high temperature and displays better catalytic activity in a wide temperature range. The introduction of 0.08% SO2 （volume ratio） in the simulated smog had evidently improved the NO conversion for all the catalysts studied. The characterization results indicate that： Tio.sZro.sO2 support is an amorphous form with a higher specific surface area and pore volume. The particles size is in a well-dispersed state on the surface. WO3 and V205 are highly dispersed on the support. And the addition of ZrO2 contributes to the higher catalytic performance.

关 键 词：V2O5 WO3 TIO2-ZRO2 催化还原 抗SO2 

分 类 号：X5[环境科学与工程—环境工程]