铈掺杂对超细LaMnO_(3+λ)催化性能的影响  

Influence of Cerium doping on Catalysis Activity of LaMnO_3

作　　者：张侃[1,2] 孙少学[2] 余高奇[1,2] 汪厚植[1] 张光德[3] 陈阳[2] 

机构地区：[1]武汉科技大学湖北省耐火材料与高温陶瓷重点实验室,湖北武汉430081 [2]武汉科技大学化学工程与技术学院,湖北武汉430081 [3]武汉科技大学汽车与交通工程学院,湖北武汉430081

出　　处：《中国稀土学报》2010年第2期171-176,共6页Journal of the Chinese Society of Rare Earths

基　　金：湖北省教育厅重点科研资助项目(2002A01018);湖北省优秀中青年人才科研计划项目(2002B011004);武汉科技大学校基金(2008XY12)资助

摘　　要：以Ce2(CO3)3,La2O3和Mn(NO3)2为原料,用"溶胶-凝胶"法结合"超临界干燥"技术,将铈掺入超细LaMnO3+λ气凝胶中。用TG-DTA,XRD,TEM,FT-IR等手段对样品进行表征;并用"2CO+2NO=2CO2+N2"反应测试铈掺杂对超细LaMnO3+λ催化活性的影响。结果显示:260℃时,镧铈锰气凝胶为疏松、絮状且具有较好分散性的棕色粉末,由大量直径小于10 nm的球形颗粒组成;850℃热处理后,镧铈锰气凝胶为粒径小于20 nm的类球形颗粒,晶相成分为LaMnO3+λ,La2O3和CeO2;铈掺杂增加LaMnO3+λ晶格的氧空缺数量,改善氧化还原催化的气氛条件,提高超细LaMnO3+λ的催化活性。The ultrafine Ce-doped LaMnO3＋λ aerogel was prepared by sol-gel method and supercritical drying method by using cerous carbonate,lathanum oxide and manganic nitrate as main materials,and characterized by TG-DTA,TEM,XRD,and FT-IR.The catalysis property of ultrafine Ce-doped LaMnO3＋λ powder was test by the reaction ＂2CO＋2NO=2CO2＋N2＂.The results showed：（1） at 260 ℃,the Ce-La-Mn aerogel was brown flocculent powder with good dispersibility.The aerogel was made up of a mass of spherical grains whose diameters were less than 10 nm.（2） After thermal treating at 850 ℃,the main crystal components of the Ce-La-Mn aerogel were LaMnO3＋λ,La2O3 and CeO2.The degree of crystallinity was advanced.The aerogel was made up of lots of quasi spherical grains that the diameters were almost less than 20 nm.Ce-doping increased the oxygen vacancies of LaMnO3＋λ lattice,improved the condition of redox catalysis,effected the migration of the perovskite lattice oxygen and advanced the catalysis activity of nano-LaMnO3＋λ.

关 键 词：纳米 LaMnO3+λ 超临界干燥 气凝胶 稀土 

分 类 号：TQ133.3[化学工程—无机化工]