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《Structural Changes of γ-Al2O3-Supported Catalysts in Hot Liquid Water》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、RESEARCHARTICLEpubs.acs.org/acscatalysisStructuralChangesofγ-Al2O3-SupportedCatalystsinHotLiquidWater†††‡†,RyanM.Ravenelle,JohnR.Copeland,Wun-GwiKim,JohnC.Crittenden,andCarstenSievers*†SchoolofChemical&BiomolecularEngineering,GeorgiaInstituteofTechnology,311FerstDriveNW,Atl
2、anta,Georgia30332,UnitedStates‡BrookByersInstituteforSustainableSystemsandSchoolofCivil&EnvironmentalEngineering,GeorgiaInstituteofTechnology,800WestPeachtreeStreetNW,Atlanta,Georgia30332,UnitedStatesbSSupportingInformationABSTRACT:Thestructuralchangesofγ-Al2O3,Ni/γ-Al2O3,a
3、ndPt/γ-Al2O3catalystsunderaqueousphasereformingconditions(liquidwaterat200°Candautogenicpressure)areexaminedoverthecourseof10h.ThechangesarecharacterizedbyX-raydiffraction,NMRspectroscopy,N2physisorption,pyridineadsorptionfollowedbyIRspectrosco-py,andelectronmicroscopy.Itisd
4、emonstratedthatγ-aluminaisconvertedintoahydratedboehmite(AlOOH)phasewithsignificantlydecreasedacidityandsurfacearea.Formetal-freeγ-alumina,thetransformationiscompletedwithin10h,whereasthepresenceofnickelandplatinumparticlessignifi-cantlyretardstheformationofboehmite.Inthebegi
5、nningofthetreatment,thesurfaceareaofγ-aluminaincreases,suggestingsurfacepittingandformationofsmallboehmiteparticlesonthesurfaceofγ-alumina.Thisprocessisfollowedbytheformationofacompactcrystallineboehmitephase.Itisproposedthatthemetalparticlesaffectthekineticsofthistransforma
6、tionbyblockingspecificsurfacehydroxylgroupsthatactasinitialhydrationsites.Thetransformationofγ-aluminaintoboehmiteisaccompaniedbysinteringofthesupportedmetalparticles.KEYWORDS:alumina,catalysis,biomass,hydrothermalstability,aqueousphasereforming,hydration1.INTRODUCTIONchalle
7、ngesforthedevelopmentofeconomicalprocessesfor5biofuelproduction.HeterogeneouslycatalyzedconversionofbiomasswilllikelyTransitionandnoblemetalssupportedonmetaloxidesup-playanimportantroleintransitioningtorenewablefeedstock-portshaveshownpotentialforcatalyticupgradingofbiomass
8、-basedfuelsandchemicals.Suchprocesseswillenablebiorefi-68neriestocompetewithtradit
