The Microstructure of Copper Zinc Oxide

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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