流化床-化学气相沉积法可控及批量制备碳纳米管

流化床－化学气相沉积法可控及批量制备碳纳米管骞伟中＊，魏飞清华大学化工系，100084,北京E-mail:[e-mail]化学气相沉积法目前已经发展成为批量制备碳纳米管的最有效率方法之一。而流化床－化学气相沉积法更是提供了大量碳纳米管充分生长的超大空间以及均匀的传热传质环境。在此，本文将总结流化床－化学气相沉积法的主要核心。1.任何可以悬浮的颗粒均可以用流化床进行连续处理。所以流化床－CVD法可以生产多种碳纳米管。碳纳米管不仅可以生长在微米级的聚团状多孔催化剂颗粒上，也可生长在毫米级的陶瓷球的表面上，还可以生长在层状无机氧化物的层间，以大量得到聚团状的碳纳米管或毫米级长度的碳纳米管阵列。2.双层变温流化床可以允许在不同级上的催化剂采用不同温度操作，从而可以调变催化剂的高温活性以便提高碳纳米管的收率。3.下行床与湍动床耦合的反应器技术可以调变催化剂还原与碳沉积的平衡，还能充分利用催化剂的活性，从而大批量制备高质量的单／双壁碳纳米管。关键词：碳纳米管；流化床；化学气相沉积。Largescaleandcontrollableproductionofcarbonnanotubesbyfluidizedbed-ChemicalvapordepositionWei-zhongQian*,FeiWeiDepartmentofChemicalEngineering,TsinghuaUniversity,Beijing,100084,ChinaChemicalvapordeposition(CVD)hasbeendevelopedasoneofthemosteffectivemethodstoproducecarbonnanotubestothisdate.Fluidizedbed-CVDhastheadvantageoflargereactorvolumetooffersufficientspacewithuniformmassandheattransfercondition,whichiscrucialtothegrowthofcarbonnanotubesinlargequantities.Here,IwillsummarizethekeypointoffluidizedbedCVD.One,anysuspendedparticlescanbedisposedcontinuouslyinfluidizedbed,whichallowsthefluidizedbedsuitablefortheproductionofmanykindsofcarbonnanotubes,whethergrownonthemicron-sizedagglomeratecatalystparticles,oronthesurfaceofmillimeter-sizedceramicspheres,aswellasonthelayeredmetaloxides.Thusfluidizedbed-CVDissuitableforthemassproductionofagglomeratecarbonnanotubesandthemillimeterlongverticallyalignedcarbonnanotubearray.Second,thetemperatureshifttwo-stagefluidizedbedoffersanuniqueoperationofcatalystindifferenttemperaturezonesindifferentpositions,andiseffectivetotailorthecatalystactivityforahighyieldproductionofcarbonnanotubesinhightemperature.Third,thecoupleddownreactorandturbulentfluidizedbedreactoriseffectivetocontrolthebalanceofcatalystreductionandcarbondeposition,andtoutilizethemaximalactivityofthecatalystintheproductionofhighqualityofsingleordoublewalledcarbonnanotubes.Keywords：CarbonNanotubes;FluidizedBed;ChemicalVaporDeposition.