| 喻瑞,赵侦超,张振宇,石川,张维萍.Pt修饰和反应气氛对富铝Cu-Beta分子筛NH3-SCR反应性能的影响[J].分子催化,2016,30(5):428-434 |
| Pt修饰和反应气氛对富铝Cu-Beta分子筛NH3-SCR反应性能的影响 |
| Effect of Pt Modification and Reaction Atmosphere on the Catalytic Perfor-mances of Cu/Al-rich Beta Zeolite in Selective Catalytic Reduction of NO by NH3 |
| 投稿时间：2016-08-01 修订日期：2016-09-28 |
| DOI： |
| 中文关键词: 铂修饰 Cu-Beta 催化剂 富铝Beta分子筛 NH3-SCR 丙烯 |
| 英文关键词:Pt modification Cu-Beta catalyst Al-rich Beta zeolite NH3-SCR Propene |
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| 中文摘要: |
| 富铝Cu-Beta分子筛具有优异的低温NH3-SCR性能，在汽车尾气脱硝中具有潜在的应用前景。本文考察了H2O、CO2、丙烯等气氛对富铝Cu-Beta分子筛 NH3-SCR反应性能的影响。发现H2O会降低催化剂的低温活性，CO2则提高低温活性，丙烯对中、低温活性均有明显抑制作用。固体13C核磁共振显示丙烯在分子筛上形成链状脂肪烃积碳，导致催化剂的活性降低。Pt修饰使丙烯存在下低温NH3-SCR活性有所提高，但在中高温度下会催化NH3氧化产生大量的N2O和NO，从而降低了NO转化率。电子顺磁共振（EPR）和紫外-可见（UV-Vis）光谱研究表明，Pt的引入使部分孤立铜离子转化为簇状多聚态铜离子，会进一步加剧高温NH3氧化反应的发生，进而降低了催化剂的活性。 |
| 英文摘要: |
| Cu/Al-rich Beta zeolite with excellent performance at low temperature in NH3-SCR reaction is a promising DeNOX catalyst for application in diesel exhaust treatment. The effects of co-feeding H2O、CO2 and propene on NH3-SCR performance of Cu/Al-rich Beta were investigated. It’s found that the low-temperature activity of Cu/Al-rich Beta was decreased in the presence of H2O, while CO2 enhanced the low-temperature activity, and propene inhibited the catalytic activity significantly at both low and medium temperatures. Solid-state 13C nuclear magnetic resonance (NMR) indi-cated paraffin as deposited carbon was formed from the polymerization of propene in zeolite, which decreased the activity. Pt modification of Cu/Al-rich Beta catalyst enhances the low-temperature SCR performance in the presence of propene, but it can catalyze ammonia oxidation at medium and high-temperatures to produce significant amounts of N2O and NO. This decreased the NH3-SCR activity. Electron paramagnetic resonance (EPR) combined with UV-Vis spectrum characterizations indicated that the introduction of Pt transformed some isolated Cu2+ into clustered Cu2+, which further enhanced the ammonia oxidation at higher temperatures so as to decrease the DeNOx activity. |
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