基于氧化铈的低温NH_(3)-SCR催化剂的研究进展  

Research Progress of Cerium Oxide-based Catalysts for NH_(3)-SCR at Low Temperature

作　　者：李娜[1,2] 陈泽东 王晶晶 张凯[1] 武文斐[1,3] LI Na;CHEN Zedong;WANG Jingjing;ZHANG Kai;WU Wenfei(School of Energy and Environment,Inner Mongolia University of Science&Technology,Baotou 014010,Inner Mongolia,China;School of Environmental Science and Engineering,North China Electric Power University,Baoding 071000,Hebei,China;Key Laboratory of Efficient and Clean Combustion,Baotou 014010,Inner Mongolia,China)

机构地区：[1]内蒙古科技大学能源与环境学院,内蒙古包头014010 [2]华北电力大学环境科学与工程学院,河北保定071000 [3]内蒙古自治区高效洁净燃烧重点实验室,内蒙古包头014010

出　　处：《材料导报》2022年第8期50-59,共10页Materials Reports

基　　金：内蒙古自治区自然科学基金(2018MS02013,2019ZD13);国家自然科学基金(51866013)。

摘　　要：选择性催化还原(SCR)技术是一种成熟的工业烟气和柴油机废气脱硝技术,但是低温(特别是在200℃以下)的NH_(3)-SCR催化剂目前仍没有工业化应用。近几年,很多学者将Ce基催化剂作为低温NH_(3)-SCR催化剂,发现Ce基催化剂有优良的低温催化性能。本文对Ce基催化剂在NO_(x)低温NH_(3)-SCR反应中的研究进展和性能进行了综述。按照CeO_(2)在催化剂的存在形式将铈基催化剂分为:铈基复合氧化物催化剂、负载型氧化物催化剂及CeO_(2)作载体的催化剂三类。影响铈基复合氧化物催化剂的活性和选择性的关键因素有催化剂的活化能、比表面积、制备方法、焙烧温度、分散性、其他金属掺杂物、氧化还原性能等,本文对这些关键因素进行了系统的分析和总结。针对负载型氧化物催化剂,重点介绍了Ce基多金属氧化物的载体(Al_(2)O_(3)、TiO_(2)、新型载体)及载体在低温NH_(3)-SCR反应中的作用。CeO_(2)作载体的催化剂,脱硝效率虽不及前两种类型的催化剂,但将金属与CeO_(2)混合或掺杂作为共同载体的催化剂的脱硝性能和抗硫抗水性能都有显著提升,值得研究者们进一步研究,文中也进行了简要介绍。随后重点研究了低温NH_(3)-SCR机制,包括E-R机制和L-H机制。最后,对NO_(x)低温NH_(3)-SCR的研究前景及未来的研究方向进行了展望。Selective catalytic reduction(SCR)is a mature NO_(x)removal technology for industrial flue gas and diesel exhaust gas.However,it is still a challenge to develop novel low-temperature catalysts for NH_(3)-SCR of NO_(x),especially at temperatures below 200℃.In the past few years,many studies have demonstrated the potential of cerium(Ce)-based catalysts as low-temperature catalysts for NH_(3)-SCR of NO_(x),it is found that Ce-based catalyst has excellent catalytic performance at low temperature.Herein,the recent progress and performance of Ce-based catalysts for low-temperature NH_(3)-SCR of NO_(x)were summarized.Based on the different roles of ceria in NH_(3)-SCR catalysts,a systematic review of the latest research progress of Ce-based catalysts in the NH_(3)-SCR reaction is performed as the following aspects:ceria-based mixed oxides,Ce-based multi-metal oxide with support,CeO_(2)used as supports.The catalytic activity and selectivity of Ce-based mixed oxides catalysts are systematically analyzed and summarized in light of some key factors such as activation energy,specific surface area,morphology,crystallinity,preparation method,calcination temperature,other metal dopant/substitute,and redox property of catalysts.For Ce-based multi-metal oxide with support,the main supporter(Al_(2)O_(3),TiO_(2)and new type supporter)and the role of supporter in NH_(3)-SCR reaction at low temperature are mainly introduced.Although the NO_(x)removal efficiency of CeO_(2)as the catalyst carrier is not as high as that of the other two types of catalysts,the catalyst mixed or doped with metal and CeO_(2)as the common supporter has significantly denitration performance and sulfur-resistant and water-resis-tant performance,which is worthy of further study,as this paper introduces briefly.Subsequently,NH_(3)-SCR mechanisms at low temperature,including E-R and L-H mechanisms,were emphasized.Lastly,the perspective and future directions of low-temperature NH_(3)-SCR of NO_(x)were proposed.

关 键 词：低温 选择性催化还原 脱硝 氧化铈 反应机理 

分 类 号：X511[环境科学与工程—环境工程]