Pt--W(Mo)2fTiO2催化剂上H2选择性催化还原NOx的分析

《Pt--W(Mo)2fTiO2催化剂上H2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全反应气稳态红外结果表明多种含氮物种作为活性中间体表现出反应活性，并且观察到有NH4+出现，但活性较低，因此我们推断掺杂W03和M003后多种含氮物种是主要活性中间体，多种催化反应中间体的形成可能是催化剂低温活性升高的主要原因。关键词：H2．SCR，Pt，W03，M003，水热处理，TPR，原位红外IIABSlRACTSelectivecatalyticreductionofNOxbyH2overPt—W(Mo)／Ti02catalystsABSTRACTEffectsofaddedW03andM003onthe

2、catalyticperformanceofPt／Ti02catalystfortheselectivecatalyticreductionofNOxbyH2(H2一SCR)havebeeninvestigated，respectively．InthisresearchaseriesofPt／Ti02、PtW／Ti02andPtMo／Ti02catalystsweredevelopedandcharacterizedbytemperature-programmedreductionofH2(I-12一TPR)，N2physisorpti

3、on(BET)，X—raydiffraction(XRD)，temperature-programmeddesorptionofNOx(NOx—TPD)andInsituDRIFTS．ActivitytestresultsshowedthataPtW／Ti02catalystwithaPtloadingof0．5wt．％andaW03contentof2wt．％showedthehighestcatalyticperformanceatlowtemperatures(100—175℃)withamaximumdeNOxconversio

4、nobtainedat125。C．PtMo／Ti02catalystwithaPtloadingof0．5叭．％andaM003contentof2wt．％alsoexhibitedthehighestperformanceatlowtemperatures(100-175℃)，andamaximumdeNOxconversionwasobtainedat150℃．HydrothermalpretreatmentCanleadtothefurtherimprovememofthecatalyticperformanceofPtW／Ti0

5、2andPtMo／Ti02catalysts．Ⅺ①resultsrevealedthattheintroductionofW03andM003facilitatesIll北京化工大学硕士学位论文thecrystallizationofPtoxidesandresultsinallinteractionwithTi02。H2-TPRshowedthatthereductiontemperatureofPtOxbecomeslowerduetotheaddedpromoter,whichisresponsiblefortheimprovem

6、entofcatalyticactivityatlowtemperature．InsituDRIFTSresultsshowedthatintroductionofW03andM003canpromotethedismutationofN02whichproduceNO+onPtandnitratespecies；Meanwhile，NO+02-I-12transientandNO+02+H2steadyIRrevealedthatnitrogenspeciesandNH4+showedreactionactivity．Consider

7、ingtheloweractivityofN地+weconcludedthatthemainreasonfortheincreaseofcatalystactivityafterintroducingW03andM003atlowtemperatureisduetomoretypesofnitrogen—containingspeciesformed．KEYWORDS：142一SCR，Pt，W03，M003，TPR，Drifts，Hydmthermal—pretreatmentIV目录第一章绪论⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯

8、⋯⋯一11．1氮氧化物的来源和危害⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯1l-2氮氧化物的消除方法⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯11．2．1NH3．．SCR．．．．．．．．．．