The different poisoning behaviors of various alkali metal containing compounds on SCR catalyst
The different poisoning behaviors of various alkali metal containing compounds on SCR catalyst
复制标题
各种含碱金属化合物对SCR催化剂的不同中毒行为
DOI：
10.1016/j.apsusc.2016.09.036
复制
发表时间：
2017-01-15
影响因子：
6.7
通讯作者：
Zhang, Li
中科院分区：
文献类型：
--
作者：
Du, Xuesen;Yang, Guangpeng;Zhang, Li
碱金属对用于NO去除的金属氧化物催化剂是有毒的。含碱物质的化学构型和作用温度会影响中毒剖面。提出了一种基于前线分子轨道分析的计算方法来确定各种含碱物质与SCR催化剂的反应行为。结果表明，各物质的中毒反应性顺序为：E（MOH）> E（M2SO4）> E（MCI）> E（MNO3）> E（MHSO4）。分级焙烧催化剂的实验活性测试表明，NaOH可以在200 ℃以下与催化剂发生反应。NaCl和NaNO3在300至400摄氏度之间的温度下开始与催化剂反应。与MOH、MCI和MNO3不同，M2SO4和MHSO4在与催化剂反应后会产生挥发性或可分解的阴离子物种，它们会在催化剂表面留下阳离子和阴离子。残留在催化剂上的硫酸根离子可以产生用于NH3吸附的活性酸中心。实验结果还表明，Na_2SO_4和NaHSO_4不会降低NO转化率。采用理论和实验相结合的方法研究了各种碱金属对反应后的影响。理论计算结果表明，碱金属的掺杂降低了体系的酸度。实验结果表明，NO转化率随未掺杂>LiCl > NaCl > KCl而降低. (C)© 2016 Elsevier B.V.版权所有。
Alkali metals are poisonous to the metal oxide catalyst for NO removal. The chemical configuration of alkali containing substance and interacting temperature can affect the poisoning profile. A computational method based on Frontier Molecular Orbital analysis was proposed to determine the reacting behavior of various alkali-containing substances with SCR catalyst. The results reveal that the poisoning reactivities of various substances can be ranked as: E (MOH) > E (M2SO4)> E(MCI) > E(MNO3)> E(MHSO4). The experimental activity tests of the catalysts calcined at stepped temperatures show that NaOH can react with the catalyst below 200 degrees C. NaCl and NaNO3 start to react with the catalyst at a temperature between 300 and 400 degrees C. Unlike MOH, MCI and MNO3, which can produce volatile or decomposable species for the anions after reacting with the catalyst, M2SO4 and MHSO4 will leave both cations and anions on the catalyst surface. The sulfate ions left on the catalyst can generate active acid sites for NH3 adsorption. The experimental results also show that Na2SO4 and NaHSO4 will not lower the NO conversion. The after-reaction influences of various alkali metals were studied using theoretical and experimental methods. The theoretical results show that the acidity decreases with doping of alkali metal. Experiments show a consistent result that the NO conversion decreases as undoped >LiCl > NaCl > KCl. (C) 2016 Elsevier B.V. All rights reserved.