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ID:39106067
大小:5.44 MB
页数:73页
时间:2019-06-24
《Mn--Ce--Ti催化剂上NH3选择性催化还原NOx的分析》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、北京化工大学硕士学位论文进了活性中间物种的生成,有利于提高催化剂的催化活性。关键词:氮氧化物,选择性催化还原,Mn-Ce.Ti催化剂,氧化还原循环ⅡABSTRACTMn—Ce—TicatalystsonNH3selectivecatalyticreductionofNOxBasedontheselectivecatalyticreductionofNOxwithNH3asthemodelreaction,westudiedthecatalyticperformanceoftheMn-Ce—Timultipleoxidecatalysts.Bymodulatingthemolarrat
2、ioofmetalcomponent,wefoundthatthehighestactivitycatalystWasMno.2Ceo.1Tio.9,whichcouldreachmorethan90%NOxconversionin150—300℃.ComparedwithMno.2Tio.8andCe0.1Tio.9catalysts,Mno.2Ceo.1Tio.9catalysthashigheractivity,aswellasgreatresistancetOH20andS02.ByusingXRD,BET,XPS,SEM,RamanandDRIFTScharacteriza
3、tionmethods,wecharacterizedandanalysedthestructureofthecatalysttoexploremechanismoftheMn-Ce·TimultipleoxidecatalystinreactionofeliminatingtheNOx.XRD,BETandSEMresultsshowedthatthecatalystsofMn-Ce-Timixedoxidepreparedbythehydrothermalmethodhavehighspecificsurfacearea.ThesynergeticeffectamongMn,Ce
4、andTicontributestoinkibtthecatalystsfromformingcystallizaionstructure.TheamorphousphasehadformedintheMn—Ce—Ticatalystparticlesthe.ItmeantthatMnOxandCe02havegooddispersionontheTi02surface.HE—TPRresultsshowedthatMno.2Ceo.1Tio.7catalystloweredthereactiontemperatureofCe4+一Ce3+,whichenhancedthereduc
5、ibilityofCe02,andpromotedtheredoxpropertiesⅡI北京化工大学硕士学位论文ofcatalyst.XPSresultsshowedthatthecomentofM/13+inthecatalystwashigherinMno.2Ce0.1Ti0.9catalyst,itmightbeduetothetworeductionprocessofCe4+_Ce3+andTi4+_Ti3+whichtransferedelectrontoMn4+andreducedtoMn3+.DRIFTSexperimentsshowedthatmoreactiveN
6、H3andN02specieswereabsorbonthesurfaceofMno.2Ceo.1Tio.7catalyst.Theproductionoftheactiveintermediates,improvedthecatalyticreaction.Inshort,thesynergeticeffectamongMn,CeandTiofMno.2Ceo.1Tio.9catalystmayproduceadualredoxcycles(M一+Ce3+HMn3++Ce4+,耐++Ti3+HMn3++Ti4+)andtheamorphousstructureplayskeyrol
7、esforthehighcatalyticdeNOxperformance.inaddition,ThesynergeticeffectamongMn,CeandTialsocomributestotheformationofreactiveintermediatespecies,thuspromotingtheNH3一SCRtoproceed.KEYWORDS:Nitrogenoxides,Selectivecatalyticreduction,Mn—C
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