铁酸镧钙钛矿改性及其复合铈基催化剂甲烷催化燃烧性能的研究.docx

铁酸镧钙钛矿改性及其复合铈基催化剂甲烷催化燃烧性能的研究
摘要
本文研究了铁酸镧钙钛矿的改性和应用于复合铈基催化剂甲烷催化燃烧方面的性能。通过改变钙离子、钛离子和铁离子的含量以及沉淀方法，制备了不同组成的铁酸镧钙钛矿，并通过XRD、SEM、TEM等手段进行表征。结果表明，钙离子和铁离子含量适宜，有利于提高铁酸镧钙钛矿的结晶度和比表面积；而加入钛离子能够改善铁酸镧钙钛矿的稳定性和活性。进一步研究表明，铁酸镧钙钛矿与铈钇混合氧化物复合后，具有较高的催化活性和稳定性，且在甲烷催化燃烧中具有较好的活性和抗CO2、H2O中毒能力。
关键词：铁酸镧钙钛矿；复合铈基催化剂；甲烷催化燃烧；改性
Abstract
ThispaperstudiesthemodificationofLa-Ca-Ti-Feperovskiteanditsapplicationinthecatalyticcombustionofmethaneincompositeceria-basedcatalysts.DifferentcompositionsofLa-Ca-Ti-Feperovskiteswerepreparedbychangingthecontentofcalcium,titaniumandironionsandprecipitationmethods,andcharacterizedbyXRD,SEM,TEMandothermethods.TheresultsshowedthattheappropriatecontentofcalciumandironionsisbeneficialtoimprovethecrystallinityandspecificsurfaceareaofLa-Ca-Ti-Feperovskite,andtheadditionoftitaniumionscanimproveitsstabilityandactivity.FurtherstudiesshowedthataftercompositewithCe-Ymixedoxide,La-Ca-Ti-Feperovskitehashighcatalyticactivityandstability,andhasgoodactivityandanti-CO2,H2Opoisoningabilityinmethanecatalyticcombustion.
Keywords:La-Ca-Ti-Feperovskite;compositeceria-basedcatalyst;methanecatalyticcombustion;modification
1.Introduction
Methaneisanimportantenergysourceandawidelydistributedgreenhousegasinnature.Inrecentyears,duetotherapiddevelopmentofindustryandurbanization,theemissionofmethanehasincreasedsignificantly,whichhasseriouslythreatenedtheenvironmentandhumanhealth.Therefore,itisurgenttofindacleanandefficientwaytoconvertmethaneintoharmlesssubstances.Catalyticcombustionofmethaneisapromisingtechnology,whichcanachievehighefficiencyandlowemission.Amongthem,ceria-basedcatalystshaveattractedconsiderableattentionduetotheiruniqueoxygenstorageandreleaseproperties,highredoxabilityandgoodthermalstability[1-3].However,thelowsurfaceareaandpoorthermalstabilityofceria-basedcatalystslimittheirpracticalapplication.Therefore,itisnecessarytomodifythestructureandpropertiesofceria-basedcatalyststoimprovetheiractivity,stabilityandresistancetoCO2andH2Opoisoning.
Perovskite-typeoxidematerialshavetheadvantage