Cu-ZSM-5/堇青石催化剂上同时消除烃和NO的研究  

REMOVAL OF HYDROCARBON AND NO BY Cu-ZSM-5 CORDIERITE CATALYST

作　　者：刘致强[1] 唐磊[1] 田东[1] 鲍卫仁[1] 王建成[1] 常丽萍[1] 

机构地区：[1]太原理工大学煤科学与技术教育部和山西省重点实验室,太原030024

出　　处：《环境化学》2011年第9期1558-1563,共6页Environmental Chemistry

基　　金：国家自然科学基金(20906067);山西省科技基础条件平台建设项目(2010091015);山西省高等学校优秀青年学术带头人支持计划资助

摘　　要：利用水热合成技术在堇青石蜂窝陶瓷载体上原位合成分子筛,分别通过离子交换法和浸渍法制备了整体式Cu-ZSM-5/堇青石催化剂,以丙烷为还原剂,在模拟柴油机尾气系统中评价了两类催化剂消除烃和NO的性能.结果表明,晶化时间48 h时,原位合成的ZSM-5/堇青石催化剂载体表面有形状规则的ZSM-5晶核生成,且具有较好的牢固度,引入活性组分铜制得的催化剂具有明显的的脱除丙烷和NO的活性.在以丙烷为还原剂的选择性催化还原过程中,整体式Cu-ZSM-5/堇青石催化剂对C3H8表现出了较高的催化转化能力.低于800 K的温度范围内,C3H8主要作为还原剂参与反应,最高转化率可达100%;高于800 K时,C3H8被氧化的反应逐渐增强;在575—895 K的温度区间,NO的最高转化率为50%左右;水蒸气的加入,对C3H8的转化几乎没有影响,但对NO的转化有明显的抑制作用,其最高转化率降低到不足40%.与浸渍法制备的催化剂相比,离子交换法制备的催化剂对NO的催化转化能力增强,但对C3H8转化的影响不大.Using hydro-thermal synthesis technique,ZSM-5 zeolite was firmly attached on the surface of honeycomb made of cordierite ceramic,called ZSM-5/cordierite.The Cu-ZSM-5/cordierite monolithic catalysts were then prepared by ion-exchange method and impregnation method,respectively.XRD showed ZSM-5 crystalline was formed on the surface of cordierite when the ZSM-5/cordierite was made after 48 h crystallization.The catalysts were evaluated in the simulated diesel-engine exhausting gas for both hydrocarbons and nitrogen monoxide（NO） removal.In the selective catalytic reduction process with propane（C3H8） as a reducing agent,the conversion of propane over the Cu-ZSM-5/cordierite catalysts was able to reach 100% in the temperature range below 800 K.Over 800 K,the oxidation of C3H8 was enhanced.In the temperature range of 575 K to 895 K,the maximum NO conversion was 50%.The addition of water vapour did not affect the conversion of C3H8,but mitigated the conversion of NO.In presence of vapour,the maximum NO conversion was up to 40 % in the same temperature range.Comparison between the catalysts made by ion-exchange and impregnation showed the former facilitated higher NO conversion;but both had the same C3H8 conversion.

关 键 词：Cu-ZSM-5/堇青石催化剂 一氧化氮 选择性催化还原 汽车尾气净化 

分 类 号：O643.36[理学—物理化学]