学科分类
/ 25
500 个结果
  • 简介:摘要:ZSM-5择形分子筛作为FCC催化中的关键材料,因其特殊的孔结构和酸度,可有效增加丙烯收率、提高汽油高辛烷值。使用改性择形分子筛制备的助剂稳定性显著提高,并且可显著提高低碳烯烃的选择性。本文制备了不同磷酸盐改性的ZSM-5,根据制备过程中各个环节的实验数据得出了三种磷酸盐所适合的催化制备方法。

  • 标签: ZSM-5 改性 磷酸盐 催化剂制备
  • 简介:ThecatalyticactivityofFe/ZSM-5fortheselectivereductionofNOtoN2withmethaneinthepresenceofexcessO2wasstudied.Fe/ZSM-5catalystswithvariousFeloadingswerepreparedbyimpregnationmethod.ItiswellknownthatmethaneisinactivewhenFe/ZSM-5asthecatalystfortheselectivecatalyticreduction(SCR)ofNOwithmethane.However,thispapershowsthatwhenthecontentofFewasabout0.5%,Fe/ZSM-5showedhighercatalyticactivityandselectivityofmethane,andputforwardmeasurableactivationforCH4isanimportantfactorforthereactionofremovalofNOxwithCH4.

  • 标签: CATALYTIC activity Fe/ZSM-5 SELECTIVE CATALYTIC REDUCTION
  • 简介:TheinfluenceofmischmetaladditiononphysicochemicalpropertiesofPtSnNa/ZSM-5catalystwasstudiedbymeansofXRF,H2chemisorption,XRD,TPR,NH3-TPDandTPOtechniques.TheresultsshowedthatthepresenceofmischmetalhadanobviousimpactonthecatalyticperformanceofthePtSnNa/ZSM-5catalyst.AsuitablecontentofmischmetalnotonlycouldenhancetheinteractionsbetweenPtspeciesandthesupport,butalsoinhibittheformationofcokeduringthereaction,thusimprovingthecatalyticactivityandstability.Inourexperiments,whenthecontentofmischmetalwas3m%,thecatalystexhibitedbestcatalyticperformance.However,thecontinuousadditionofmischmetalcouldpromotethereductionofSnspeciestometallictin,whichwasdisadvantageoustothereaction.

  • 标签: 混合稀土 催化性能 丙烷脱氢 ZSM-5催化剂 X射线荧光光谱 反应过程
  • 简介:教主的联盟者组织了ZSM-5独块巨石通过转变宏的骨骼被准备多孔的硅石胶化进由帮助蒸气的conversionmethod.The形态学和宏的整体的形状的ZSM-5多孔的硅石胶化preserved.Thehierarchically很好被组织ZSM-5独块巨石展出了层次孔,与在宏内存在的中央毛孔andmacropores多孔的硅石胶化,并且ZSM-5.Theproducts形成的微毛孔被使用XRD,SEM和N_2adsorption-desorptionmethods适当地描绘了。

  • 标签: 沸石 ZSM-5 等级孔隙度 大孔硅凝胶 蒸汽转化 吸附
  • 简介:AseriesofZSM-5zeolites,withthemorphologiesofsphere,spherewithcubicparticlesonthesurface,andcubicparticles,weresynthesizedbyhydrothermalmethodusingn-butylamineasthetemplate,assistedbytheadditionofNaClandcrystalseed.X-raydiffraction(XRD),scanningelectronmicroscope(SEM),X-rayfluorescence(XRF)andtemperature-programmeddesorptionofammonia(NH3-TPD)wereusedtocharacterizethesesamples.Thesamplesweretestedwithtoluenemethylationreaction.Themodifiedsamplecomposedofsphericalparticleswith3μmcrystalparticlesonthesurfacehadapara-xyleneselectivityof95%andmaintained79%oftheinitialconversionafterrunningthereactionfor50h.Thismodifiedsampleshowedthebeststabilityamongthetestedthreemodifiedsamples.

  • 标签: ZSM-5沸石 烷基化反应 对二甲苯 催化性能 扫描电子显微镜 NH3-TPD
  • 简介:催化在炼油工业中担负着如此重要的角色,所以正如SaudiAramco公司的几位工程师SaeedSAIAIIoush,GeneYeh和AbdullahMAitani所描述:SaudiAramco公司已建立了公司自己的管理备忘录

  • 标签: 催化剂 标准 炼油工业 工程师 公司 备忘录
  • 简介:研究、设计和使用物质尺寸小于一微米的纳米技术,是一个迅速发展的领域。从医疗保健、药品开发到飞机制造和建筑行业,几乎没有一个行业不受益于纳米技术,不管是具有优异性质的新型材料或是纳米级的工具、传感器和发电机。

  • 标签: 纳米技术 催化剂 建筑行业 医疗保健 飞机制造 药品开发
  • 简介:随着合成氨工业技术的不断发展,一氧化碳低温变换反应对合成氨装置的经济运行起着至关重要的作用,而CO的最终变换率取于低温变换催化的性能,要求低变催化具有较高的活性,以便在较低温度下使反应达到平衡。川化催化厂根据市场变化和低变催化生产工艺的发展需要,研制生产出了新一代CB-5型低温变换催化,在数家大、中、小型合成氨厂得到广泛使用。

  • 标签: 合成氨 CB-5型 低温变换催化剂 使用 综述
  • 简介:CarbondepositionduringmethanoltohydrocarbonsleadstothequickdeactivationofZSM-5catalystanditisoneofthemajorproblemsforthistechnology.DecreasingthecrystalsizeorintroducingmesoporesintoZSM-5zeolitescanimproveitsdiffusionpropertyanddecreasethecokeformation.Inthispaper,nano-sizedZSM-5zeolitewithintercrystallinemesoporescombiningthemesoporousandnanosizedstructurewasfabricated.Forcomparison,themesoporousZSM-5andnano-sizedZSM-5werealsoprepared.ThesecatalystsampleswerecharacterizedbyXRD,BET,NH3-TPD,TEM,Py-IRandTGtechniquesandusedontheconversionofmethanoltogasolineinafixed-bedreactoratT=405°C,WHSV=4.74h-1andP=1.0MPa.Itwasfoundthattheexternalsurfaceareaofthenano-sizedZSM-5zeolitewithintercrystallinemesoporesreached104m2/g,largerthanthatofmesoporousZSM-5(66m2/g)andnanosizedZSM-5(76m2/g).Catalyticlifetimeofthenano-sizedZSM-5zeolitewithintercrystallinemesoporeswas93h,whichwasonlylongerthanthatofmesoporousZSM-5(86h),butshorterthanthatofnanosizedZSM-5(104h).Strongaciditypromotedthecokeformationandthusdecreasedthecatalyticlifetimeofthenano-sizedZSM-5zeolitewithintercrystallinemesoporesthoughitpresentedlargeexternalsurfacethatcouldimprovethediffusionproperty.Thespecialzeolitecatalystwasfurtherdealuminatedtodecreasethestrongacidity.Afterthis,itscokeformationratewasslowedandcatalyticlifetimewasprolongedto106hbecauseofthelargeexternalsurfaceareaanddecreasedweakacidity.Thisspecialstructuralzeoliteisapotentialcatalystformethanoltogasolinereaction.

  • 标签:
  • 简介:本发明提供了一种用于CH2=CHR烯烃聚合反应的催化组分,其中R为氢或G-C6的烷基或芳基,该催化组分包含镁、钛、卤素和给电子体,该给电子体选自通式(略)的至少一种二醇酯化合物,其中R1-R4可相同或不相同,为氢或C1-C10直链或支链的烷基、C3-C10环烷基、C6-C10芳基、

  • 标签: 烯烃聚合 给电子体 催化剂 组分 芳基 二醇
  • 简介:本发明提供了一种用于CH2=CHR烯烃聚合反应的催化组分,其中R为氢或C1-C6的烷基或芳基,该催化组分包含镁、钛卤素和给电子体,该给电子体选自通式(略)中的至少一种醇酯化合物,通式中的R1-R10可相同或不相同,为氢或C1-C10直链或支链的烷基、C3-C10环烷基、C6-C10芳基、C7-C10烷芳基或芳烷基,

  • 标签: 烯烃聚合 给电子体 催化剂 组分 芳基 烷基
  • 简介:FreshZSM-5zeolitecatalystswerepretreatedat460℃and500℃withvariouscumulativeamountofwaterfeed(CAWF)inafixedbedreactor.Thecatalyticprocesswascarriedoutunderthefollowingconditions:atemperatureof480℃;amethanolWHSVof3h-1;amethanolpartialpressureof30kPa;andatimeonstreamof12h,24hand48h,respectively.TheBETparametersofcatalystsanddiffusioncoefficientsoftolueneshowedthatthereweretwotypesofmesoporesgeneratedunderdifferenthydrothermalconditions.MildtemperatureandmoderateCAWFconditionsledtoexternalopenmesoporeswhichcouldbeenteredfromtheexternalsurfaceofthezeolite,whileahightemperatureorahighCAWFconditionresultedinthegenerationofmacroporesorinternalisolatedmesopores,whichwereoccludedinthemicroporousmatrix.TheTGAresultsshowedthatcatalystwithexternalopenmesoporeshadgoodabilitytoresistcokeaccumulationandgoodperformanceonpropyleneselectivity,whiletheinternalisolatedmesoporesdidnocontributetotheincreaseddiffusivityofreactantsandproducts.

  • 标签: METHANOL to PROPYLENE (MTP) HYDROTHERMAL treatment
  • 简介:摘要:使用NH4Cl溶液对以四乙基溴化铵为模板合成ZSM-5工业原粉分别进行焙烧前后的铵交换实验,采用火焰光度法测量铵交换前后Na2O含量并计算出交换度,考察焙烧前后对分子筛铵交换效果的影响,并分析出现交换度差异的原因。

  • 标签: ZSM-5分子筛 铵交换 四乙基溴化铵