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CatalystsApplicationIntroductionMichaelChengEddielinAug.26,2008Part1TWCFundamentalsIntroduction2008-8-273汽车催化转化器AutomotiveCatalyticConverter2008-8-274三效催化剂的组成TWCComponents载体Substrate涂层Washcoat氧化铝Alumina储氧材料OxygenstorageComponent助剂Promotersandstabilizers贵金属PreciousMetalPt,PdandRh2008-8-275载体Substrates陶瓷Ceramicz堇青石Cordierite–2MgO-2Al2O3-5SiO2–热稳定性ThermalStability1300oC金属Metallicz铁铬合金Fe-cralloy–Fe,Cr,Al–Yand/orCeadded–热稳定性ThermalStability1300oC2008-8-276整体式载体MonolithicSubstratesClose-upviewofmetallicmonolithCeramicmonolithsubstratesCeramicfoamMetalmonolith2008-8-277HCCONOX1313.51414.51515.516Air/FuelRatioNO+CON2+CO2H2O+COH2+CO2SO2+H2/COH2SH2O+HCCO+H2NO+H2NH3CO+O2CO2HC+O2CO2SO2+O2SO3NO+O2NO2三效催化剂的反应ReactiononTWC2008-8-278三效催化剂的工作环境OperatingConditionsofTWC温度Temperature¾冷启动时，每分钟300oC的加热速率Heat-upratesof300oCperminuteoccurduringcold-start¾即使在热车时，加速和减速也会引起每分钟正负100oC的变化Evenafterwarm-up,changesof±100oCperminutearecausedbyvehicleacceleration&decelerationconditions¾排气温度可以高达900oCThetemperatureofexhaustgascanreach900oC气体成分GasComposition¾在加速状态（强还原）和减速状态（强氧化）下不停地转换Constantlyshiftsbetweenaccelerationmode(stronglyreducing)anddecelerationmode(stronglyoxidizing)¾“波动”气流，这是三元催化剂工作的基本原则，引起频繁的氧化还原变化“Perturbated”flow,whichisfundamentaltoTWCoperation,causessecond-to-secondredoxchanges2008-8-279三效催化剂中贵金属的功能PreciousMetalFunctioninTWC氧化剂Oxidants:O2,NOx还原剂Reductants:HC,CO,andH2¾在任何时候都有可能有过量的O2,NOx或HC,CO和H2Atanymoment,theremaybeexcessofO2,NOxorHC,CO,andH2¾Pt和Pd是很好的HC和CO氧化催化剂PtandPdaregoodoxidationcatalysts¾Rh是好的NO还原催化剂RhisagoodNOreductioncatalyst2008-8-2710三元催化剂的贵金属系统PreciousMetalSystemsforTWCCatalystsPt/Rh传统。对燃油中的硫中毒有最好抵抗力。Traditional.MostresistantPMtofuelsulfur/poisons.Pt-好的氧化作用。生成一些NH3。Goodoxidation.SomeNH3formation.Rh–极好的NOx还原作用。高温下易与Al2O3反应丧失活性。ExcellentNOxreduction.ReactswithAl2O3duringhightemperatureexposuretoloseactivity.Pd/Rh因为更清洁的燃油而新近推出的。Recentintroductionduetocleanerfuels.分层涂敷用来避免形成合金。Washcoatlayeringusedtoavoidalloying.Pt/Pd/Rh高含量Pd与Rh和Pt的分离涂敷有高温稳定性和好的HC活性。HighPdloadingsegregatedfromRhandPtyieldshighthermalstabilityandbetterHCactivity.RhandPt加上金属氧化物改善Rh和NOx反应的热稳定性。Rh&PtplusMetalOxidesimprovethermalstabilityoftheRhNOxreactionPdOnly高温位置有卓越的去除包括NO污染物的整体性能。HightemperaturelocationsyieldexcellentoverallperformanceincludingNOx2008-8-2711专有的涂层工艺ProprietaryWashcoatProcess使原子级的催化剂工程技术得以实现AllowsAtomicScaleEngineeringofCatalyst贵金属以原子态散布在特殊基层金属氧化物载体上PreciousMetals(Pt,Pd,Rh)CanbeAtomicallyDispersedonSpecificBaseMetalSupports(AluminaorCeria)对贵金属功能具有特别促进作用AllowsSpecificPromotionofPreciousMetalFunction避免形成低性能合金和贵金属与基层金属氧化物的化合物AvoidsFormationofPoorerPerformingAlloysandPM/BMOCompounds(Rh-aluminate)使原子级的催化剂工程技术得以实现使原子级的催化剂工程技术得以实现AllowsAtomicScaleEngineeringofCatalystAllowsAtomicScaleEngineeringofCatalyst贵金属以原子态散布在特殊基层金属氧化物载体上贵金属以原子态散布在特殊基层金属氧化物载体上PreciousMetals(Pt,Pd,PreciousMetals(Pt,Pd,RhRh))CanbeAtomicallyDispersedonSpecificBaseMetalSupports(AluCanbeAtomicallyDispersedonSpecificBaseMetalSupports(AluminaorminaorCeria)Ceria)对贵金属功能具有特别促进作用对贵金属功能具有特别促进作用AllowsSpecificPromotionofPreciousMetalAllowsSpecificPromotionofPreciousMetalFunctionFunction避免形成低性能合金和贵金属与基层金属氧化物的化合物避免形成低性能合金和贵金属与基层金属氧化物的化合物AvoidsFormationofAvoidsFormationofPoorerPerformingAlloysandPM/BMOCompounds(PoorerPerformingAlloysandPM/BMOCompounds(RhRh--aluminatealuminate))PdPdBMO1BMO1RhRhBMO2BMO22008-8-2712三效催化剂的微观电镜图SEM&TEMpicturesofTWC5nm2008-8-2713三效催化剂生产过程ProductionProcess载体Substrate浆料Slurry涂敷Coating干燥Drying焙烧Calcining包装Packing发货Shipping仓储Storage来料检验In-ComingInspection浆料检验SlurryInspection出货检验Out-GoingInspection2008-8-2714结论Conclusions三效催化剂必须同时进行氧化反应和还原反应TWCmustsimultaneouslydooxidationandreductionchemistries三效催化剂必须应对苛刻且多变的应用环境TWCmustcopewithrapidchangesincondition三元催化剂中贵金属的选择取决于其应用SelectionofPreciousMetalsforTWCCatalystsDependsontheApplication:排放法规EmissionsRegulation燃油控制系统FuelControlSystem燃油品质QualityofFuel三元催化剂中贵金属的功能PreciousMetalFunctioninTWCCatalyst:Pt,Pd氧化OxidizingRhNO还原NOReduction单Pd多用于紧藕合催化剂设计PdforSpecialCloseMountedCatalystDesignsBASF公司专有的涂层技术提供卓越的催化活性和耐久性BASF’sProprietaryWashcoatTechnologyProvidesSuperiorCatalyticActivityandDurabilityPart2TWCProposalDesign2008-8-2716催化剂配方设计所需信息InformationrequiredforproposaldesignSOPRequirementforOBDthresholdsampleEngineagingcycleEmissionengineeringtargetEmissiondataofengineout(Temperature,HC,CO,NOx,lambda)ConverterlayoutSubstratedefinitionSubstratesupplierConvertersupplierEMSsupplierEmissionstandardEngineparameter(Displacement)VehicleweightandseatingVehicleplatform2008-8-2717载体目数对床温的影响HighCellDensityProvidesFasterTemperatureRiseDuringCold-StartSAEPaper#982634Corninget.al.2008-8-2718载体规格对背压的影响PressureDropasaFunctionofFlow2008-8-2719载体目数对排放性能的影响TestResultsShowBenefitswith600&900cpsiSubstratesSubstrate(cpsi/mil)SubstrateWt.ReductionGSANMHCEngine-OutNMHCTailpipe400/6.5027.31.7260.103600/32135.31.6740.073900/22843.71.7160.0601200/22550.81.7540.062CatalystsOven-aged@1050°CFTPTestsonNissanaltima;CatsinClose-CoupledPositionSAE1999-01-02712008-8-2720三效催化剂的布局设计MakerlayoutofTWCExample1Example3Example2Example4(Single-brickZon