钙钛矿催化材料La-1-x-Ce-xCoO-3-的制备-表征及甲烷燃烧催化性质

第14卷第9期中国有色金属学报2004年9月Vol.14No.9TheChineseJournalofNonferrousMetalsSep.2004文章编号:10040609(2004)09158005钙钛矿催化材料La1-xCexCoO3+�的制备、表征及甲烷燃烧催化性质�崔梅生,李明来,张顺利,龙志奇,崔大立,黄小卫(北京有色金属研究总院有研稀土新材料股份有限公司,北京100088)摘�要:采用柠檬酸发泡法制备了钙钛矿LaCoO3催化材料;研究了Ce对La进行掺杂替代对催化材料性能的影响;通过BET、XRD、SEM等手段对催化材料进行了物性表征;以甲烷完全燃烧为目标反应,研究了钙钛矿La1-xCexCoO3+�的催化性能。结果表明:铈掺杂对材料晶相有较大影响,当掺杂量x小于0.3时,粉体晶型基本不变,而当掺杂量达到0.5时,有明显CO3O4晶相出现,LaCoO3钙钛矿晶相完整性遭到破坏,当掺杂量大于0.7时,钙钛矿晶相大大弱化甚至消失;LaCoO3是一种性能优良的甲烷燃烧催化材料,Ce的掺杂替代对催化材料活性有明显影响,并增强了催化材料的高温稳定性能,铈最佳掺杂量为0.3;前驱体经700�焙烧形成了较为完整的钙钛矿晶型,经800�焙烧后,催化材料最高活性为:t10%=390�,t90%=603�。关键词:柠檬酸;钙钛矿;甲烷;催化燃烧;稀土中图分类号:O643文献标识码:APreparationandphysico-chemicalcharacterisationofLa1-xCexCoO3+�perovskitecatalystanditsmethanecatalyticcombustionCUIMe-isheng,LIMing-lai,ZHANGShun-li,LONGZh-iqi,CUIDa-li,HUANGXiao-wei(GriremAdvancedMaterialsCo.Ltd,GeneralResearchInstituteforNon-ferrousMetals,Beijing100088,China)Abstract:PerovskiteoxidesLaCoO3methanecatalyticmaterialswerepreparedwithcitratecomplexationandbubblingmethod.TheceriumdopingeffectwasstudiedinseriesLa1-xCexCoO3+�materialsbyBET,XRDandSEMtechniques.Andtheircatalyticbehaviourswerealsostudiedwithmethanecatalyticcompletecombustionasprobereaction.Theresultsshowthatdopedceriumhasgreateffectsonthecrystalphaseformed.Whendopedceriumcontentxislessthan0.3,thephasesofpowdersarelittlechanged.Whendopedceriumxisupto0.5,obviousCo3O4phaseisdiscovered,andtheintegrityofLaCoO3perovskitecrystalphaseisbroken.Whenxisover0.7,perovskitecrystalphaseisgreatlyweakenedorcompletelydisappeared.Consideringthecrystalphaseofpowders,theoptimumceriumdopingcontentisabout0.3.PerovskiteoxidesLaCoO3aregoodmethanecatalyticmater-ials.Dopingceriumhassomepositiveactivityeffectandthethermalstabilityofthematerialisalsoenhanced.Theperovskiteoxidecanbeformedatlowercalcinationtemperature,about700�,andwhenxis0.3,thebestcatalyticactivityisacquiredast10%=390�andt90%=603�inseriesofLa1-xCexCoO3+�materialscalcinatedat800�.Keywords:citricacid;perovskite;methane;catalyticcombustion;rareearth�基金项目:国家高技术研究发展计划资助项目