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1、太原理工大学 硕士学位论文 柴油车尾气净化蜂窝状Fe-Mo/ZSM-5催化剂的试验研究 姓名：庄永涛 申请学位级别：硕士 专业： 指导教师：李哲 太原理工大学硕士研究生学位论文 I 柴油车尾气净化蜂窝状 Fe-Mo/ZSM-5 催化剂的试验研究 摘摘 要要 柴油车因为在动力性、燃油经济性和稳定可靠性等方面有着汽油机不 可比拟的优势，其用途已不再仅仅局限于船用和大型卡车、公交车的动力 系统，而是已逐渐扩展到各类车型上。中国在未来几年的排放标准要求与 国际接轨，达到欧。单纯依靠机内净化措施已经远远不能满足现在日益 严格的排放要求。因此将机内净化和排气后处理有机的结合起来成为未来 解决柴油车排放问题
2、的主要技术手段。 SCR是一种适合柴油车的NOx催化净 化净化后处理技术。 课题组前期研究发现Fe-Mo/ZSM-5在以NH3为还原剂的 NOx-SCR反应中具有很好的催化活性和较宽的活性温度窗口。为了能把粉 末催化剂应用到实际当中去，我们把催化剂涂覆到蜂窝状堇青石载体上， 考察了催化剂制备方法、助剂、载体涂覆方法对蜂窝状催化剂的影响。并 进行了蜂窝状车载催化剂的设计和中试试验。得出的主要结论如下： (1) 本项目所采用的涂载技术不论对共浸渍法样品， 还是气相离子交换 法样品，其所制备的蜂窝状催化剂的活性与其粉末样品的活性相差不大， 个别样品甚至还有所提高。 (2) 不同的蜂窝状陶瓷载体对催化
3、剂的催化性能也存在一定的影响。 对 于相同大小尺寸的蜂窝状载体，采用相同的涂覆方法。康宁载体在催化剂 的涂覆量和催化活性要高于山西净土载体。 太原理工大学硕士研究生学位论文 II (3) 制备方法对蜂窝状催化剂的活性有显著的影响。 气相离子交换法制 备的样品，不论是粉末催化剂还是蜂窝状催化剂，其催化活性明显高于共 浸渍法制备的样品，且温度窗口要宽于共浸渍法制备的样品。 (4) 在气相离子交换法制备的粉末样品中加入 K+有助于改进粉末催化 剂的低温活性和高温稳定性。而加入 B4+，则导致其高温催化活性下降。 (5) 催化剂活性的高低不仅与活性组分的类别、 载体本身性质有关， 而 且与活性组分的负
4、载量有关。在一定的范围内，活性组分的负载量越大， 催化剂活性越高。随着负载量的增加，催化活性达到最高，再增加活性组 分的负载量，催化剂催化活性没有明显提高。 (6) 确定了整体式催化剂的壳体的形状为圆柱形， 这种形状的壳体便于 焊接，刚度好，装配工艺简单。衬垫材料则采用陶瓷纤维网垫，它可以起 到良好的固定作用，使得陶瓷载体免受外力的冲击和振动，同时有效地防 止尾气从陶瓷载体与壳体间的缝隙处泄露。 (7) 从稳态转化效率测试结果可以看出，该催化消声器在 250基本可 以达到 50%以上的转化效率，具有较宽的转化效率窗口。排放的 NOx满足 欧排放标准。 关键词：蜂窝状陶瓷载体，选择性催化还原(S
5、CR)，Fe-Mo/ZSM-5 催化剂， 涂覆方法 太原理工大学硕士研究生学位论文 III EXPERIMENTAL STUDY OF DIESEL EXHAUST REDUCTION HONEYCOMB Fe-Mo/ZSM-5 Catalyst ABSTRACT Because of the power fuel economy and stability of reliability,Diesel vehicles has a incomparable advantages compared with gasoline engine it is no longer confined to
6、marine and large trucks,but gradually expanded to all mobile vehicles.In the future years,the emission standards with international standards to reach Europe .A simple internal Purification is far not enough to meet the increasingly stringent emission requirements.Therefore,organic combination of th
7、e internal Purification and exhaust emissions after-treatment become the future solution methods of diesel exhaust emissions.SCR is suited to catalytic removal of NOx from diesel vehicles.Preliminary studies by our group found that Fe-Mo/ZSM-5 catalyst with NH3 as reducing agent in the NOx-SCR react
8、ion has good catalytic activity and a wide temperature window. In order to applied the powder catalyst to the practical.we are coating the powder catalyst to honeycomb cordierite carrier and reviews the effect of preparation methods of catalyst、auxiliary agent、coating methods of carrier to the activ
9、ity of honeycomb-catalyst.Then design honeycomb catalyst for vehical and carry on intermediate test. This paper draws the following conclusions: 太原理工大学硕士研究生学位论文 IV (1) The technology used in the project, both of the co-impregnation sample, and vapor ion-exchange samples are able to guarantee its hon
10、eycomb catalyst activity the same as the activity of powder samples , individual samples are even increased. (2) Different kinds of honeycomb carrier are also have certainly effects to the activity of catalyst. For the same size of carrier ,we apply the same coating methord.Catalyst made by Corning
11、carrier, the amount of the catalyst coating, catalytic properties, is superior to the Catalyst made by Shanxi carrier. (3) The preparation method of the honeycomb catalyst activity has a significant impact. honeycomb catalyst or powder catalyst samples were prepared by vapor ion-exchange, its cataly
12、tic activity was significantly higher than the samples prepared by co-impregnation, and the temperature window is more broader than the total samples prepared by co-impregnation. (4) The powder samples prepared by vapor ion-exchange method adding K+ ions help to improve the low temperature of cataly
13、st activity and high temperature stability.To join the B4+ ions, have resulted in its high-temperature catalytic activity decreased. (5) The level of catalytic activity not only with the category of active component, but also to the load amount of the active component.To same degree,the coating amou
14、nt of active component greater the higher of the catalytic activity.As the load increases,the catalytic activity reach highest.keeping increasing the amount of active components,the catalytic 太原理工大学硕士研究生学位论文 V activity did not significantly improve. (6) Determining the shape of overall catalytic is
15、cylindrical.the shape of the shell is facilitate welding,good stiffness, simple assembly process. Cushioning material is ceramic fiber mat, which can play a good fixation, making ceramic carrier from external shocks and vibrations, while effectively preventing exhaust from the ceramic substrate and
16、the shell in gaps leak. (7) The steady-state conversion efficiency tests show that the catalytic conversion efficiency can basically reach more than 50% at 250 , conversion efficiency has a wide window. NOx emissions to meet Europe emissions standards. KEY WORDS: honeycomb ceramic carrier，selective catalytic reduction, Fe-Mo/ZSM-5 catalysts，coating methods 太原理工大学硕士研究生学位论文 1 第一章 绪 论 1.1 引
