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ID:40405639
大小:324.75 KB
页数:4页
时间:2019-08-01
《The Microstructure of Copper Zinc Oxide》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、Communicationsplantsthatproducemorethan5000tonsofmethanolperday,supportedcoppernanoparticlesareemployedashighlyactiveheterogeneouscatalysts.Fortheefficientuseofnaturalresourcesthedesignofmoreactiveandselectivecatalystsisrequired.However,structure–activityrelationshipsareo
2、ftendeducedfrommodelsystemsexhibitingstructuralcharacter-isticsverydifferentfromthoseofindustrialcatalysts.Herewe[1]describethemicrostructureofcoppernanoparticlesonzincoxidepreparedsimilartoindustriallyusedcoppercatalystsandexhibitingcomparablecatalyticactivities.Supporte
3、dcoppernanoparticlesareactivecatalystsformethanolsynthesis,methanoloxidation,andmethanolsteamreforming.Structure–activityrelationshipsforcoppercata-lystshavebeenstudiedextensivelywithavarietyofmaterialsrangingfromsingle-crystalmodelsystemstomultiple-com-ponentindustrialca
4、talystswithcopperconcentrationsof[2]morethan50%.Severalsuggestionsweremadeastothe[3]natureofthe“real”structureofthecopperphaseunderreactionconditions,includingthesimplifyingassumptionthat[4]theactivityincreaseslinearlywiththecoppersurfacearea.Conversely,coppernanoparticle
5、swerepreparedrecentlywithsurfacesdisplayingdifferentcatalyticactivities.Inadditiontothesurfacearea,bulkstructuralparameterslikemicrostraininthecopperparticleswereidentifiedtocorrelatewiththe[5–7]catalyticactivityofthesecatalysts.Onlyfewmicroscopicstudiesofthe“real”structu
6、reof[8–10]activecoppercatalystshavebeenreported.High-reso-lutiontransmissionelectronmicroscopy(TEM)andinsituTEMstudieshavebeenperformedoncopperparticlessupportedonZnOwithacopperconcentrationoflessthan[11,12]10%.Thesestudiesshowedfacetedwell-orderedCuparticlesonalargeandwe
7、ll-definedZnOsupport.ChangesinthemorphologyoftheCuparticles,theratioofthecopperfacets,andthesurfaceareauponvaryingthereductionpotentialofthegasphasewereimpressivelyillustratedbyinsituTEM.However,thesecoppermodelsystemswereHeterogeneousCatalysispreparedbyimpregnationofZnOc
8、rystalswithasolutionofcopperacetate.Thispreparationproceduredeviatesconsid-TheMicrostructureofCo
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