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PDS催化脱硫反应机理的研究(Ⅱ)——反应机理模型的实验佐证 Introduction Theremovalofsulfurdioxidefromfluegasesisanessentialstepinordertoreduceairpollution.ThePDS(promotediron-baseddesulfurization)processhasprovedtobeaneffectivetechnologyforsulfurremovalduetoitshighefficiency,lowcost,andeco-friendliness.Despitethegeneralsuccessoftheprocess,thedetailedmechanismsofthePDSreactionpathwayareyetnotclear.Hence,thepresentstudyaimstoinvestigatethemechanismofthePDSreactionthroughanexperimentalverificationoftheproposedreactionmechanismmodel. ExperimentalDesign Theexperimentaldesignincludestheselectionofthereactants,PDScatalyst,andreactionconditions.Thechosenreactantsweresulfurdioxide(SO2)andhydrogensulfide(H2S)gases,andthePDScatalystwasFe2O3/TiO2inaweightratioof10:1.Thereactionconditionsweresetasfollows:areactiontemperatureof200°C,agasflowrateof100mL/min,andacatalystweightof3g.Thegas-phasecompositionsforSO2andH2Swere400ppmv,respectively. ReactionMechanismModel TheproposedPDSreactionmechanismmodelisbasedonthefollowingthreesteps: 1.TheadsorptionofSO2andH2SonFe2O3/TiO2catalystsurface 2.ThereductionofSO2andH2Stosulfurandwatervapor,respectively,bythehydrogenformedonthecatalystsurface 3.TheadsorptionofsulfuroncatalystsurfacefollowedbyitsoxidationtoSO2inthepresenceofO2. ExperimentalResults TheresultsobtainedfromtheexperimentsshowedthatthePDSreactionfollowedtheproposedreactionmechanismmodel.TheadsorptionofSO2andH2SonthecatalystsurfaceformedintermediatespeciessuchasSxOyandFeS,asconfirmedbytheX-rayphotoelectronspectroscopy(XPS)analysis.Theseintermediateproductsarelaterreducedtosulfurandwaterbythehydrogenformedonthesurface,asrevealedbythehydrogenadsorptionandtemperatureprogrammedreduction(TPR)studies.Finally,theoxidizationofsulfuronthecatalystsurfacetoSO2inthepresenceofO2wasconfirmedbythein-situdiffusereflectanceinfraredFouriertransformspectroscopy(DRIFTS)andactivitytrackingstudies. Conclusion TheexperimentalresultsconfirmedthevalidityoftheproposedPDSreactionmechanismmodel.TheadsorptionofSO2andH2Sonthecatalystsurfac