铜改性水滑石衍生氧化物及其吸附-还原NO的性能  

Copper Doped Hydrotalcites Derived Oxides and Their Adsorption-Reduction Performance with NO

作　　者：张淼[1] 韩伟[2] 吕刚[1] 宋崇林[1] 李博[1] 陈科[1] Zhang Miao Han Wei Lu Gang Song Chonglin Li Bo Chen Ke(State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China National Automobile Quality Supervision and Test Center （Xiangyang）, Xiangyang 441004, China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]国家汽车质量监督检验中心(襄阳),襄阳441004

出　　处：《燃烧科学与技术》2016年第4期377-383,共7页Journal of Combustion Science and Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2013CB228506);国家自然科学基金资助项目(51476115);天津市应用基础及前沿技术研究计划资助项目(13JCZDJC35800)

摘　　要：采用共沉淀法和浸渍法制备了贵金属负载均匀、Cu物种高度分散的系列改性水滑石衍生复合氧化物催化剂,并对其理化特性和稀燃氮氧化物捕集净化性能进行了实验研究.结果表明:Cu的引入不会破坏水滑石晶体的微观层状结构,且500,℃的焙烧温度能够保证Cu物种均匀分散在衍生复合氧化物体相中;Cu取代Mg能够降低催化剂表面吸附活性位的碱性,而随Cu取代比例的增加,催化剂表面亚硝酸盐吸附物种比例减少,硝酸盐吸附物种比例增加;随Cu取代比例的增加,NO脱附峰值温度和NO吸附量均先增加后降低;在H2为还原剂的模拟稀燃氮氧化物捕集反应中,Cu取代比例为20%,的催化剂样品对NO的净化效率高达90%,.A series of multi-elemental oxides catalysts derived from Cu modified MgAl hydrotalcites with well dis-persed noble metal and Cu species are prepared by co-precipitation and impregnation methods.Their physic-chemical properties and the performance of NOx storage and reduction under lean-burn conditions are also investigated.The experimental results indicate that Cu loadings do not destroy the micro layered structure of hydrotalcites crystal,and Cu species are well dispersed in the derived oxides after being calcined at 500,℃.The Cu substitution of Mg elements reduces the basicity of active sites on the surface of catalysts,and with the increase of Cu contents,the ratio of ad-sorbed nitrite species decreases,while the ratio of adsorbed nitrate species increases. Meanwhile,both the peak tem-perature of NO desorption and the NO adsorption capacity firstly increase and then decrease with the increase of Cu loading. The catalyst of 20%, Cu content can increase the NO reduction efficiency to 90%, with H2 as the reductant in the simulated lean NOx tap reactions.

关 键 词：水滑石 稀燃氮氧化物捕集 NO脱附 Cu取代 柴油机 

分 类 号：TK427[动力工程及工程热物理—动力机械及工程]