氧在La-SrMnO3(001)吸附、解離和擴散的第一性原理研究.pdf

1、蘭州理工大學碩士學位論文氧在LaSrMnO3(001)吸附、解離和擴散的第一性原理研究姓名：國星申請學位級別：碩士專業(yè)：材料加工工程指導教師：路文江；湯富領20120607氧在La／SrMn03(ooi)吸附、解離和擴散的第一性原理研究AbstractMoreandmoreattentionhasbeenpaidonthefieldofcleanefficientdistributedgenerationinrecentyearsAtt

2、hesanletime，thesolidoxidefuelcellisthemosteffectivedevicetotransformhydrocarbonenergytoelectricalenergythroughtheelectrochemicalreaction’111esolidoxidefuelcell(SOFC)wasinventedtotransformthechemicalfueldirectlyintoelectr

3、icitySo，itismostappropriateSOFCcathodematerialsCathode／electrolyteinterfacerestoretheoxygenmoleculestooxygenionsThereactionisastrongoxidizingatmosphere；perovskitesurfaceoxygenadsorptionanddiffusionmechanismoft11eirelectr

4、ochemicalperformanceisveryimportantAnalysisofreactionmechanism，theisotopetracermethod(“02)foundthat02／LSCsurfaceoxygenadsorptiondecidethecathodereactionmteInotherwords，thefhststepoftheadsorptionreactiondeterminestheperfo

5、rmanceofthesolidcathodematerialsTherefore，usingthefirstprinciplesmethodbasedondensityfunctionaltheoryWestudyLa／SrMn03electricalpropertiesandconducivemechanismandcompareLa／SrMn03on(001)threeexteriorfaceoftheadsorptionofOa

6、toms，and02moleculesineachsurfaceduringthedissociationprocess，becauseithasimportantpracticalsignificanceWeadoptVASPsoftwaretocalculatelatticestructureandelectricalperformanceofLa／SrMn03，usingfirstprinciplepseudopotentialp

7、lanewavecalculationsandtheNudgedElasticBandmethodbasedondensityfunctionaltheorytostudythedissociationofmolecularoxygenonLa／SrMn03(oo0surfaceandthesubsequentdifl陋ionofatomicoxygenintothemagnesiumsubstrateWeprovide02molecu

8、lesdissociationpathontheouterMn02，LaOandSrOsurfaceandtheenergybarrierinvestigatediffusionprocessesofOatomonthreeoutersurfacesLa／SrMn03(001)bycalculationforeachpositionpotentialbarrierandthestabilityofthebasicsituationoft

9、headsorptionpositionOnthisbasis，wecomparethevaluesoftheactivationenergiesforthestepsofdissociationdiffusionanddesorptionproposedissociationof02andreleaseoxygenduringsurfaceratedeterminingstepFinallyweproposethatsolidcath

10、odematerialfortheLa／SrMn03asthefirststepindeterminingperformancewhentheadsorptionreactionprovidesatheoreticalsupportfordataKeyword：Firstprinciplescalculation；Solidoxidefuelcells；Electricalproperties；Adsorptionanddissocia