SHS方法制备的锰铁系NH_3-SCR催化剂的性能研究和机理分析  

Investigations of Performance and Mechanism on SHS-prepared Ferromanganese NH_3-SCR Catalyst

作　　者：朱霖[1] 林赫[1] 管斌[1] 黄震[1] 

机构地区：[1]上海交通大学动力机械及工程教育部重点实验室,上海20240

出　　处：《车用发动机》2012年第3期72-77,共6页Vehicle Engine

摘　　要：为提高传统选择性催化还原(SCR)催化剂低温窗口的NO去除效率,运用自蔓延高温合成法(Self-Propagating High-temperature Synthesis)制备了一系列低温锰铁系催化剂。对其在SCR法去除NO中的反应性能进行评价,分析了活性组分和液相点燃温度的影响;利用X射线衍射仪(XRD)对催化剂晶型进行表征,并使用原位漫反射傅里叶变换技术(in situ DRIFTS)进行反应机理研究。实验结果表明:MnO_x有良好的低温活性,Fe的引入能在改善其N_2选择性的同时保持优秀的低温活性;SHS方法制备的该类催化剂的性能随着点燃温度升高而下降;原位分析表明Brφnsted酸和Lewis酸都参与了Ti_(0.9)Mn_(0.05)Fe_(0.05)O_(2.8)的SCR反应,其中前者具有更高的活性;单齿硝酸盐为关键的活性硝酸盐物种。To improve NO removal efficiency of low temperature SCR catalyst,a series of ferromanganese catalysts were prepared with the method of self-propagating high-temperature synthesis(SHS).The performance of catalyst in DeNO reaction was evaluated and the influences of active components and liquid ignition temperature were analyzed.The crystal form of catalyst was characterized by X-ray diffraction device and the mechanism of reaction was researched with in situ DRIFTS technology. The experimental results show that MnO_x has a high activity at low temperature.The introduced Fe improves the N_2 selectivity and keeps the activity at low temperature.The performance of SHS-prepared catalyst decreases with the increase of ignition temperature.The in-situ analysis indicates that both BrφΦnsted acid and Lewis acid participate in the SCR reaction of Ti_(0.9) Mn_(0.05)Fe_(0.05)O_(2-8) and that the former has a higher activity.In addition,the monodentate nitrate is the key active nitrate species.

关 键 词：氮氧化物 催化剂 选择性催化还原 原位漫反射 红外光谱 表面酸性 

分 类 号：TK414.5[动力工程及工程热物理—动力机械及工程]