La_(0.8)Ce_(0.2)Mn_(1-x)Ni_xO_3系列催化剂结构及其对碳烟催化氧化反应的影响  

La_(0.8)Ce_(0.2)Mn_(1-x)Ni_xO_3 Catalysts:Structure and Its Effect on the Catalytic Activity for Soot Oxidation

作　　者：武政杰 宋崇林[1] 吕刚[1] 宋金瓯[1] 吴少华[1] 张立淼[1] 

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

出　　处：《燃烧科学与技术》2015年第3期267-273,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(51206119);天津市应用基础及前沿技术研究计划资助项目(13JCZDJC35800)

摘　　要：采取凝胶-溶胶法制备了系列取代型La0.8Ce0.2Mn1-xNixO3（x＝0-0.4）钙钛矿型催化剂，并采用多种先进的分析手段对催化剂的物理化学特性和碳烟氧化反应催化活性进行了表征．结果表明：适量 Ni 在 B 位的取代不会严重破坏钙钛矿的晶相结构，但会导致晶格尺寸减小；随着 Ni 取代量的增加，取代型催化剂的比表面积和表面吸附氧含量均先增加后降低，而催化剂微观表面由棉絮状结构向蜂窝状结构转变，同时形成较大的蜂窝状孔道，但当 Ni取代量达到40%时，催化剂团聚体表面重新变得致密；随着 Ni 取代量的增加，所合成系列催化剂的碳烟氧化反应特征温度、活化能和指前因子等均先降低后增加，其中La0.8Ce0.2Mn0.8Ni0.2O3催化剂表现出最好的碳烟氧化反应催化性能．催化剂的碳烟氧化反应催化活性与其微观结构、比表面积和表面吸附氧含量具有相关性．A series of La0.8Ce0.2Mn1-xNixO3（x=0—0.4）perovskite-type catalysts were prepared by sol-gel method. The physical-chemical properties and the catalytic activities of those catalysts were analyzed by several analytical methods. The results showed that partial amounts of Ni substitution at B site induceno damages to the crystalline structure of the perovskites but a decrease in the crystalline size is observed. With the increase of Ni substitution,the specific surface area（SSA）and the amount of surface adsorbed oxygen（O2）of La0.8Ce0.2Mn1-xNixO3 increase firstto some extent and then begin to decrease. Furthermore,the microstructure of the catalysts changes from cotton struc-ture to honeycomb structure and larger channels are formed. For La0.8Ce0.2Mn0.6Ni0.4O3,however,the microstructure becomes again dense. With the increase of Ni substitution,the characteristic temperatures,activation energies and frequency factors of catalysts prepared all show an increasing trend after the initial decrease. Among all the catalysts, La0.8Ce0.2Mn0.8Ni0.2O3 exhibits the highest catalytic activity for soot oxidation,which is found to be attributed to the microstructure,SSA and？-O2.

关 键 词：钙钛矿 碳烟 催化活性 活化能 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]