酸碱催化课课件下

SAPO-34分子筛合成实例解决的基础问题Si原子是如何进入分子筛骨架的如何控制Si原子在分子筛骨架中的分布分子筛的合成与制备结构&组成催化性能DICPAl(1Si)Al(1Si)Al(3Si)Al(4Si)HigherSi/AlStrongeracidicsitesDICPXRDspectraofas-synthesizedsamplesDICPCrystallizationcurveofSAPO-34DICPIRresultsDICPAssignmentoftheIRbandsinframeworkvibrationregionoftheas-synthesizedsamplesCrystalli-zationTimeStructureTypeAsym.StretchSym.StretchT-OBendingP-O-Al(P-O-P)O-P-OSi-OP-O(Al-O)D-6RingsPO4(Si,Al)O4SiO4RingsChannel0hGel12251090785730-618570520470365-0.5hGel-1070-730-618570-475365-1hCrystal12151100-730635570530480-3801.5hCrystal12151100-730635570530480-380DICPInfluenceofcrystallizationonthecompositionofsolidsamplesRelativecontentcurveoftemplateintheas-synthesizedsamplesDICP31PNMRofthegelsamplesinthefirststepsofthecrystallizationprocessThestirredmixinggeloftherawsources(silicasol,pseudoboehmite,orthophosphoricacidandwater)Thestirredmixinggelofa.andtemplate(TEA).Theb.gelafteraging(theinitialstateofthecrystallization).

DICP27AlMAS(a),31PMAS(b)and29SiCP/MAS(c)NMRspectraofas-synthesizedsamplesintheearlierstageofcrystallizationabcDICP27AlMASNMRspectraofcalcinedanddehydratedsamplesintheearlierstageofcrystallizationDICPChangesoftheAl(IV),P(IV)andSi(IV)relativecontent(a)andrelativeproportion(b)oftheas-synthesizedsampleswithcrystallizationtime(a)relativecontent(b)relativeproportionDICP晶粒以Si(4Al)方式生长(2.5h)初始凝胶(0h)重排聚合形成晶核(0.5h)晶粒生长~80%Si直接进入骨架Si(nAl)n=0-4结构形成(26h)Si取代P2Si取代Al+PSi直接参与相对结晶度~80%SAPO-34晶化机理模型DICP4.分子筛的基本性质基本特点多孔晶体，规整孔道结构大比表面积结构多样性组成多样性高热稳定性，水热稳定性基本性质离子交换性质吸附性质固体酸碱性质DICPDICPDICPDICPDICPDICPDICP5.分子筛的表征XRD：

晶相，晶胞参数，晶体结构电子显微镜：晶貌，组成吸附－脱附：比表面积，孔径，孔容、酸碱性等红外光谱（IR)：－OH；酸碱性质；骨架；表面物种NMR：结构微环境分析；酸碱性质热重－差热：热稳定性，酸碱性，吸附（脱附）性质，积碳分析注意：XRD图随组成也有变化DICP去除模板剂前后XRD图有变化DICPXRD测定结晶度一般测定8个主峰即可也可用于测定杂晶相对结晶度Sumofpeakheights(unknown)Sumofpeakheights(standard)%Crystalinity=DICPXRD测定Si/Al比晶粒必须大于0.3微米组成变化引起晶胞参数变化，XRD呈现规律性可以测定Si/Al判断晶体中是否有不均匀Al分布DICP％Al＝16.5－30.8

HZSM-5DICPIR法测定Si/Al只对特定体系适用组成规律变化会体现在IR光谱中DICPDICP分子筛酸性的测定酸碱中和（指示剂法）TPDIR1H-NMR31P-NMRTPD和IR最常用DICPH-MAS-NMRspectrumofHYzeoliteDICPIRspectraofHYzeolitewithoutandwithadsorbedpyridine

HYHY+Pyridine(sodalite)(supercage)(B)(Lewis)DICPPyridineadsorptionondifferentzeolitessamplesP.A.Weyrich,W.F.Holderich,Appl.Catal.A158(1997)145.DICP

++MethodAcidTypeAcidLocation(Int./Ext.)AcidAmountAcidStrengthMajorDrawbacksBrønstedLewisTitration

─++AccessibilityTPD(Basesadsorption)

++─+±Diffusion&Non-acidicadsorptionIR(hydroxyls)+───+SamplepreparationIR(Basesadsorption)+++±±Samplepreparation1HNMR(hydroxyls)+──±+Wateradsorption31PNMR

(TMP)++─+

(B)─(L)+

(L)─(B)Volatile,Oxidization&Toxicity31PNMR(PhosphineOxides)++++(B,L)+(B,L)WeakerbasicityComparisonofVariousAcidCharacterizationMethodsDICPNH3-TPDofH-ZSM-5Zhaoetal.,J.Phys.Chem.B,106,4462(2002)DICP1H&27AlMASNMRofH-ZSM-5SpinningRate=5.0kHzSpinningRate=5.5kHzDICPIntroducingthePlayersTMP(Trimethylphosphine)Sizeca.0.55nmTMPO(TrimethylphosphineOxide)Sizeca.0.55nmTBPO(TributylphosphineOxide)Sizeca.0.82nmZSM-5(10-MR)DICPSamplePreparationProceduresTMPAdsorptionthermaldecomposition

oftrimethylphosphinesilveriodidecomplexontothedehydratedH-ZSM-5at473KTMPO(TBPO)AdsorptionH-ZSM-5dehydration723K;24haddTMPO/TBPOdissolvedinCH2Cl2underN2gloveboxLoadedSampleCH2Cl2evacuationvesselagitatedatRT;12h323KunderN2gloveboxpackingintoMASrotor31PMASNMRDICPTMP/BrønstedacidsiteTMPO/Brønstedacidsite

IonicPairComplex

HydrogenBondedComplexLunsfordetal.,J.Am.Chem.Soc.,107,1540(1985)Muelleretal.,J.Phys.Chem.B,102,2890(1998)

InteractionsBetweenProbeMoleculesandBrønstedAcidSitesHigherAcidicStrength

O-HBondStrength

31PChemicalShift

(downfield)FormationofTMPH+complexDICP31PMASNMR(TMP/H-ZSM-5/26)Assignments-4ppm:

TMPH+/Brønstedacidsites-50ppm:

TMP/Lewisacidsites-62ppm:

Physisorbed

TMPNOTE:Acidsiteswithdifferentstrengths

cannotbedifferentiated!!CP/MASDecouplingWithoutdecouplingSpinningRate=7kHzLBLunsfordetal.,JACS,107,1540(1985)DICP31PMASNMR(TMPO/H-ZSM-5)1501209060300Chemicalshift(ppm)HZSM-5/15HZSM-5/26HZSM-5/75HZSM-5/15(Partiallyhydrated)******************MobileTMPO

Uptofive31Presonancewereobserved@86,75,67,63and53ppmforTMPO/Brønsted

IncreasingSi/Al

AcidicStrength

NoLewisacidsitesobserved

Thenewlyobserved30ppmpeakcanbeascribedduetomobileTMPO

TMPOcanprobesbothinternalandexternalacidsitesSpinningRate=10kHzDICPCorrelationofResultsObtainedfromTMPOandTBPO(a)TMPO(b)

TBPO********646948(P)58(P)7074SpinningRate=10kHzZhaoetal.,J.Phys.Chem.B,106,4462(2002)

AdsorptionofTMPOandTBPOonAl-MCM-41(Si/Al=70;poresize=2.54nm)ChemicalShift(

)

c

1(

1-c)

2(

2-c)TMPO3969(30)64(25)TBPO4774(27)70(23)Muelleretal.,J.Phys.Chem.B,102,2890(1998)

MechanismofAcidSiteFormationinAl-MCM-41?DICP31PMASNMRofCrystallineTBPODICPAcidPropertiesofH-ZSM-5Determinedby

31PMASNMRinConjunctionwithICP

TMPO(Internal+External)

(

)/ppm86(47)75(36)67(28)63(24)53(14)43(4)30Sample(Si/Al)H-ZSM-5/150.5%(---,0.005)22.4%(0.165,

---)37.5%(0.258,

0.017)36.6%(0.242,0.027)3.0%(0.021,---)

H-ZSM-5/266.9%(0.014,0.010)45.4%(0.159,---)22.7%(0.067,0.012)25.0%(0.063,0.025)----

----H-ZSM-5/753.5%(0.003,0.002)69.8%(0.108,---)----(---,0.002)26.7%(0.032,0.009)----

----TBPO(External)

(

)/ppm92(45)----75(28)71(24)----54(7)47Sample(Si/Al)H-ZSM-5/1510.5%----35.0%54.5%------------H-ZSM-5/2622.3%----25.2%52.5%------------H-ZSM-5/7515.4%----17.6%67.0%----

(1)

refertochemicalshiftdifferencew.r.t.crystallineTMPO(39ppm)orTBPO(47ppm).(2)

Datainparenthesesdenote(Int.,Ext.)acidconcentrationsin(0.05)mmol/gcat.(3)Assume1:1relationbetweenadsorbateandBrønstedacidsite.ICPprobidesconcentrationsofAl,SiandP.DICP31PNMRChemicalShiftAssignmentsforVariousCatalystsAdsorbedwithTMPOandTBPODICPDistributionofAcidSitesforVariousCatalystsDICP6.分子筛的催化性能分子筛的特点多孔晶体

孔道结构规整Shapeselectiveeffect

比表面积大Highactivity

组成可调变性酸、碱性可调离子交换性氧化还原性能TS-1，?..

结构可调变性据反应特点选择分子筛Shape-selectiveeffect规整孔道结构使分子筛具有特殊的催化性能ReactantshapeselectivityProductshapeselectivityReactantshapeselectivityandproductshapeselectivityarestronglydependingoncrystalsizeandactivityRestrictedtransitionstateshapeselectivityRestrictedtransitionstateshapeselectivityisindependentofcrystalsizeandactivity,butdependsonporeandcavitydiametersandonzeolite’sstructuresDICPReactantshapeselectivityProductshapeselectivityDICPReactantshapeselectivityDehydrationofn-andiso-butanolonCa-XandCa-ADICPProductshapeselectivityCH3OHC5-C11，汽油C2-C4，烯烃ZSM-5SAPO-34MTGMTOCH3OH＋toluene

p-xylene改性ZSM-5DICPLiquidPhaseAlkylationofNaphthaleneoverLargePoreZeolitesRRBackgroundPENPBN塑料液晶中间体---中法PICS项目T-butylationofNaphthalenewitht-butanolReactionResultsreactiontime=2hsNo1-TBNRestrictedtransitionstateshapeselectivityDisproportionationofdialkylbenzeneovermediumporezeolite(HMd,ZSM-5)双分子反应，形成中间过渡态需要较大的空间Theactivityonvariouszeolites(ZSM-5,ZSM-4,Mordenite,Y)werecorrelatedwiththeireffectiveporesize.DICP分子筛催化的液相有机反应酸碱功能芳烃的亲电取代反应烷基化酰化卤化脂肪族化合物的亲核取代反应酯化

缩合反应异构化、重排消去、加成分子筛催化的液相有机反应金属功能氧化反应酸性－金属双功能Cat:TS-1,...DICP重要的分子筛A:(detergents,desiccationandseparation);FAU:X(desiccation,purification,separation)andY(separation,catalysis);MOR:(adsorptionandcatalysis);LTL:KL-typezeolite(catalysis:aromatization);MFI:SilicaliteandZSM-5(adsorptionandcatalysis);BEA:Beta-typezeolite(catalysis:cumene);MTW:zeoliteMCM-22(catalysis:ethylbenzene,probablycumene?);CHA:SAPO-34(methanoltoolefinsorMTOprocess-demonstrationunit);FER:Ferrierite(skeletalisomerizationofn-butenes-demonstrationunit);AELand/orTON:SAPO-11andpossiblyZSM-22(improvementofpourpointforpetroleumcutsbystraightlongparaffinisomerization);Structuresnotrevealed(foraromaticC8isomerization):oneiscertain(IFP)andthesecondispossible(UOP).DICP7.规整孔道介孔材料DICPMobilresearchersin1992,cationicsurfactantporesize1.5-10nm,highsurfaceareas1200m2/glowhydrthermalstability,basicconditionHexagonal(p6m)LiquidcrystaltemplateroutesCubicIa3dlamellarMCM-41MCM-48MCM-50ANewFamilyofMesoporousMaterialsM41SDICP介孔材料的形成机理1.层状机理：1993年G.D.Stucky1996年日本Inagaki:pHdecreasingThemechanismforformationofFSM-16

2.棒状机理：1994年M.E.DavisA.Monnieretal.Science,261,1299(1993)C.Chen,etal.MicroporousMater.,4,1(1995)S.B.Inagaki,CHEMSOCJPN69,1449(1996)

DICP介孔材料的形成机理CooperativeAssemblyApproach:Q.Huoetal.Nature,368,317(1994).DICPmicroporouszeolitesMCM-41poresize<1.1nmporesize2-6nmApplications:catalysis,separation,adsorption,sensor,nanodeviceandfabricationofnanostructuredmaterialsadvantageinthemassdiffusionandtransportbecauseoftheirinterconnectingnetworksBicontinuoushelix3DcubicmesostructureIa3d,MCM-48J.Thomas,O.Terasakietal.,Acc.Chem.Res.

2001,34,583-594DICPCubicCagedMesoporousSilicaSBA-1lowtemperaturesynthesis,-5°C,acidsynthesis,largeheadgroupsurfactant,C16H33N(Et)3BrwelldefinedmorphologyanepitaxialphasetransformationO.Terasaki,T.Tatsumi,JACS,2002,123,12089Q.Huoetal.Nature,368,317(1994).DICP

3Dcagedstructure,cubicIm3mtriblockcopolymerwithlongEOchainsF127,EO106PO70EO106,F108,F98,Brij700,acidsynthesis,highlyorderedXRDpatternsN2sorptionisothermsD.Zhao,etal.J.Am.Chem.Soc.

1998,120,60248.0nmLargePoreCubicCagedSBA-16O.Terasaki,D.Zhaoetal.Nature408,449(2000)100110111Cellparametera=13.3nmWindowsize2.3nmCavitysurfaceSpherediameterd=9.5nm

XRDpatternsStructuremodelDICPMesoporousSilicaMCM-48andCarbonsCMK-4R.Ryooetal.,J.Phys.Chem.B,103,7743,1999.S.Jun,S.H.Joo,R.Ryoo,etal.,J.Am.Chem.Soc.,122(43);10712-10713,2000.S.Joo,R.Ryooetal.,MicroporousMesoporousMater.,44-45,153-158,2001.DICPD.Zhao,Science,1998,279,548TEMimagesoMesoporousSilicaSBA-15blockcopolymertemplatingacidicsynthesisconditionlargeporesize(4.6~40nm)thermallyandhydrothermallystablehighlyorderedthicksilicawall,microporouswallshighsurfaceareas(~1000m2/g)porevolume(1.0—2.5cm3/g)N2sorptionisothermsXRDpatternsD.Zhao,etal.J.Am.Chem.Soc.

1998,120,6024S.-H.Joo,R.Ryoo,M.Jaroniec,J.Phys.Chem.B2002,106,4640N2sorptionisothermsinitialpartsof

plotsDICPSynthesisofMesoporousMaterials

Surfactant

+Inorganicsource

hydrothermalSyntheticCharactersforMesoporousMaterials：1.lowtemperature,-5°C~RT,<150°C2.fastformationrate<1min3.compositionisvariable,tetrahedron,octahedron4.non-aqueoussynthesis,surfactanttemplating5.morphologycontrolStructurecharacters:1.non-perfectcrystal,longrangeorder(nocode)2.amorphousinorganicwalls3.weckinteraction(H-bonding,ligand,vanderWaals)4.hydrothermallyunstablepH,mediamesoporousmaterialsDICPSynthesisRoutestoMesoporousMaterialsQ.Huoetal.Nature,368,317(1994).S.A.Bagshaw,etal.Science,269,1242(1995)J.Y.Ying,ANGEWCHEMINTEDIT38,56(1999)D.Zhao,Science,1998,279,548MCM-41(p6m),MCM-48(Ia3d),MCM-50(L),SBA-6(Pm3n),SBA-8(cmm),FUD-2(Fd3m)

f,I+…X…H+SS=nonionicsurfactant,blockcopolymersNon-silicaoxidemesostructures,e.g.W,MoSBA-3(p6m),SBA-1(pm3n),SBA-2(P63/mmc),MHS,MUX,worm-likedirorderedmesoporeHexagonal,cubicmesostructures,Nb,TaSBA-15(p6m),SBA-16(Im3m),SBA-12(P63/mmc),

SBA-11(Pm3m),FDU-1(Im3m),FDU-4,5SBA-13,14DICP8.分子筛研究的几个热点方向DICPSessionsin13-IZCMineralogyofnaturalzeoliteZeolitenucleationandgrowthNewmethodsofzeolitesynthesisIsomorphoussubstitutionsSynthesisofnewmaterialsFundamentalsofmicelletemplatingNewmesoporousmolecularsievesSyntheseswithnon-ionicsurfactantsCrystalstructuredeterminationHost-guestchemistryPost-synthesismodificationIn-situspectroscopyandcatalysisFrameworksandacidsitesFrameworks,cations,clustersModellingandtheoreticalstudiesAModellingandtheoreticalstudiesBPrinciplesofadsorptionAdsorptionandseparationprocessDiffusion:fundamentalapproachZeolitemembranesandfilmsNanocompositefundamentalsandapplicationsAdvancedmaterialsMicro-andmesoporous

materialsinfinechemistryNewroutestohydrocarbonactivationConversionofaromaticsCatalysisforoilrefiningSelectiveoxidationandsulfurresistanceConfinementandphysicalchemistryforcatalysisNewapproachestocatalystpreparationEnvironmentalcatalysisEnvironment-friendlyapplicationsofzeolitesZeolitemineralsandhealthsciencesDICP几个热点方向传统分子筛研究仍持续保持活力AvelinoCorma,MariaJ.Diaz-Cabanas,JoaquinMarti