纳米钙钛矿型ABO_x(A=La、Y;B=Mn、Co、Ni)的制备、表征及其对NO+CO的催化活性  

Preparation and Characterization of Nano-ABO_x( A =La,Y; B =Mn,Co,Ni)and Their Catalytic Activity for Removal of NO + CO

作　　者：钱方兵 王丽[1] 沈建宇[1] 符娇鸾 吴可永 陈潇[1] 

机构地区：[1]宁波大学材料科学与化学工程学院,浙江宁波315211 [2]宁波市新型功能材料及其制备科学实验室,浙江宁波315211

出　　处：《稀土》2014年第3期87-93,共7页Chinese Rare Earths

基　　金：浙江省自然基金项目资助(Y5080288);宁波市自然基金项目资助(2013A610077)

摘　　要：为研究纳米钙钛矿型稀土氧化物ABOx中A、B组合对NO+CO催化活性的影响规律及机理,采用柠檬酸溶胶-凝胶法制备了6个钙钛矿型稀土复合氧化物LaMnOx、YMnOx、LaCoOx、YCoOx、LaNiOx、YNiOx,用X射线衍射(XRD)、扫描电镜(SEM)、比表面积(BET)、X射线光电子能谱(XPS)对其进行了表征,测试了它们对CO+NO的催化活性。所得催化剂对CO的催化活性顺序为:LaNiOx>YCoOx>YNiOx>YMnOx>LaCoOx>LaMnOx,对NO的催化活性顺序为:LaNiOx>YCoOx>YNiOx>LaCoOx>YMnOx>LaMnOx。LaNiOx的催化活性最好,350℃时NO和CO转化率均为100%。结果表明,B位Mn、Co、Ni离子的价态和外层d电子数、催化剂的比表面积及其氧的存在形式是影响催化活性的重要因素。而价态相同、半径不同的La3+或Y3+通过对晶格氧和B位Mn、Co、Ni价态的影响,从而对催化活性也有较大的影响。In order to research the regulation among A and B on the catalytic activity of the nanoperovskite ABOxfor NO＋ CO and the catalytic mechanism,perovskite type oxides ABOx（ A = La,Y; B = Mn,Co,Ni） were prepared by a citric acid sol-gel method and characterized by X-ray diffraction（ XRD）,scanning electron microscopy（ SEM）,X-ray photoelectron spectroscopy（ XPS） and N2physisorption（ BET）. The catalytic activity of the oxides for NO ＋ CO was tested. The obtained results indicated that the activity of catalysts for CO is in the order of LaNiOx〉YCoOx〉YNiOx〉YMnOx〉LaCoOx〉LaMnOxxand that for NO is in the order of LaNiOx〉YCoOx〉YNiOx〉YMnOx〉LaCoOx〉LaMnOx. LaNiOxexhibits the best catalytic activity and complete conversion of CO and NO at 350 ℃. Valence state and d-electron number of B,specific surface area and the kind of oxygen in catalyst are the key factors influencing catalytic activity. Different A（ La^3 ＋,Y^3 ＋） in catalysts with same B have great impact on catalytic activity through influencing lattice oxygen（ OL） and valence of B.

关 键 词：纳米钙钛矿氧化物 NO+CO 催化活性 催化机理 

分 类 号：TG335.11[金属学及工艺—金属压力加工]