Effect of C3H6 on selective catalytic reduction of NOx by NH3 over a Cu/zeolite catalyst: A mechanistic study
Effect of C3H6 on selective catalytic reduction of NOx by NH3 over a Cu/zeolite catalyst: A mechanistic study
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DOI：
10.1016/j.apcatb.2012.04.038
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发表时间：
2012-07-23
影响因子：
22.1
通讯作者：
Epling, William
中科院分区：
文献类型：
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作者：
Luo, Jin-Yong;Oh, Harry;Epling, William
采用阶跃响应法反应器试验研究了乙炔对Cu/β沸石催化剂上关键SCR反应的影响。在标准SCR条件下，C3 H6在200 ℃及以上明显抑制还原反应。原位DRIFTS结果表明，C3 H6对NH3的抑制作用不是由C3 H6和NH3之间的竞争吸附引起的，而是由C3 H6氧化过程中形成的表面中间物种引起的，包括丙烯醛类和焦炭类物种。与标准SCR反应类似，C3 H6也对快速SCR反应具有负面影响。空间傅里叶变换红外光谱（空间分辨毛细管入口傅里叶变换红外光谱）的结果表明，NO2被C3 H6迅速还原为NO，导致发生一些标准的SCR，而不是纯粹的快速SCR。而C3 H6对NO2 SCR有积极的影响。C3 H6将NO2还原为NO导致发生与NO2 SCR组合的快速SCR反应而不是纯NO2 SCR。反应途径的改变也显著降低了N2 O的生成。(C)2012爱思唯尔有限公司版权所有。
The effects of C3H6 on key SCR reactions over a model Cu/beta zeolite catalyst were characterized using step-response method reactor testing. Under standard SCR conditions, C3H6 clearly inhibited the reduction reaction at 200 degrees C and above. The inhibition was not caused by competitive adsorption between C3H6 and NH3, but by surface intermediate species formed during C3H6 oxidation, including acrolein-like and coke species as indicated by in situ DRIFTS. Similar to the standard SCR reaction, C3H6 also had a negative effect on the fast SCR reaction. Spaci-FTIR (spatially resolved capillary-inlet Fourier transform infrared spectroscopy) results indicated that NO2 was quickly reduced to NO by C3H6, leading to the occurrence of some standard SCR instead of purely fast SCR. However, C3H6 had a positive effect on NO2 SCR. The reduction of NO2 to NO by C3H6 resulted in the occurrence of the fast SCR reaction combined with NO2 SCR instead of pure NO2 SCR. The reaction pathway change also decreased N2O formation significantly. (C) 2012 Elsevier B.V. All rights reserved.