文档名：负载镧掺杂无定形二氧化钛的介孔光催化氧化脱硫催化剂
摘要：为了开发高活性油品光催化氧化脱硫催化剂,以样品La-TiO2为活性组分,样品SBA-15为载体合成了以镧掺杂无定形二氧化钛为活性组分的介孔催化剂(La-TiO2/SBA-15),采用X射线衍射(XRD)、X射线荧光光谱(XRF)、氮气吸附-脱附(BET)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FT-IR)、紫外-可见光谱(UV-Vis)、光致发光光谱(PL)、X射线光电子能谱价带谱(VB-XPS)进行表征,应用于含二苯并噻吩(DBT)的模拟柴油及真实柴油的光催化氧化脱硫,同时提出光催化反应机理.催化活性从高到低为:样品La-TiO2/SBA-15,样品La-TiO2,样品TiO2,样品SBA-15,这是因为样品SBA-15的高比表面积和有序介孔结构促进了活性组分的分散和DBT的扩散,镧掺杂拓宽了光响应范围,提高了吸光度,降低了光生电子-空穴的复合率.捕获实验表明,?O2-和h+是主要活性中间物种.优化后工艺条件为催化剂用量1%(质量分数),氧化剂中氧原子与硫化物中硫原子摩尔比n(O)/n(S)=15:1,剂油体积比(V(extractant)/V(modelfuel))=1:1,脱硫率达95.12%,且循环使用4次后仍高于85%,真实柴油在催化剂用量3%(质量分数),n(O)/n(S)=20:1,V(extractant)/V(modelfuel)=1:1的条件下脱硫率达64.7%.
Abstract：IntroductionAsasemiconductormaterialwithsuperioropticalproperties,amorphousTiO2withthevalenceband,conductionband,andbandgapstructureofcrystallineTiO2ispronetoformingalooseporousstructurewithmoresurfacedefects.Duringthephotocatalyticreactionprocess,itcangeneratealargenumberofelectronandholecapturetraps,whichisconducivetoimprovingaphotocatalyticefficiency.However,itsphotocatalyticactivitystillneedstobeimproved.Wideningitsabsorptionrange,narrowingitsbandgapandpromotingthemigrationoftheinternalelectron-holetothesurfacetoreactwiththetargetproductareallstillthecurrentimportantresearchaspects.DopingorloadingisanormalmodificationmethodofTiO2.Thedopingwithrare-earthelementLaissimpleandeffective,narrowingthebandgapofTiO2andreducingtheenergyconsumptionofphotocatalyticreaction.Tofurtherimprovethephotocatalyticactivity,loadingLa-TiO2onSBA-15canbeaneffectiveoption.ThehighspecificsurfaceareaandthemesoporesofSBA-15canbebeneficialtothedispersionoftheactivecomponentandthediffusionofreactants,therebyimprovingthephotocatalyticperformance.Inthispaper,TiO2wasfirstlydopedwithLa,andLa-TiO2wasthensupportedonmesoporousmolecularsievesSBA-15.TheobtainedcatalystLa-TiO2/SBA-15wascharacterizedandappliedinthephotocatalyticoxidationdesulfurizationforthemodelandrealdieseloil.Inaddition,thephotocatalyticreactionmechanismwasalsoproposed.Methods4mmoltetrabutyltitanatewasdroppedslowlyintoasolutionof0.9mLofdeionizedwaterwith10mLofabsoluteethanolundermagneticallystirringuntilawhitegelwasgenerated.Afterstirringfor0.5h,thewhitegelwasagedat25℃for14h,andthenstirredat40℃untiltheabsoluteethanolwascompletelyevaporated.ThiswhitepowderbecomesanamorphousTiO2afterdryingat100℃andgrinding.ThesynthesisprocessofLa-TiO2wassimilartothatofamorphousTiO2.However,deionizedwaterwasreplacedwithasolutionoflanthanumnitrate(ItsconcentrationwascalculatedaccordingtothedopingamountofLa).TosupportLa-TiO2onSBA-15,lanthanumnitrateandtetrabutyltitanatewereputinto10mLabsoluteethanol.TheratioofthefeedstocksinthismixtureissameasthatofthesynthesisofLa-TiO2.SBA-15mesoporousmolecularsievewasalsoputintothismixture,andtheloadingofLa-TiO2onthesupportedcatalystwas10%(inmasscontent).1mLdeionizedwaterwasdroppedslowlyintothemixtureunderstirring.TheX-raydiffraction(XRD)patternsofthesamplesweredeterminedonamodelD/max-RBX-raydiffractometerwithCu-Kαradiationoperatingat40kVand150mA.ThecompositionofthecatalystwasidentifiedbyamodelD/max-RX-rayfluorescencespectrometer(XRF)withatungstentargetat40kVand50mA.Theelementalquantitativeorsemi-quantitativeanalysiswascarriedoutbasedonthecharacteristicpeakintensityofeachelement.TheporestructurewascharacterizedbyamodelASAP2010physicaladsorptioninstrument(BET).After16-hpretreatmentinvacuumat110℃,N2adsorption-desorptionwasoperatedat-196℃.Thetransmissionelectronmicroscope(TEM)imagesweredeterminedonamodelJEM-2010CXelectronmicroscopeat200kV.TheFourier-transforminfraredspectra(FT-IR)intherangeof4000-400cm-1wererecordedonamodelWQF510spectrometerataresolutionof4cm-1.TheUV-Visdiffusereflectionspectra(UV-Vis)wererecordedonamodelCary2450UV-VisspectrometerwithBaSO4asareferencesampleinthewavelengthrangeof200-800nm.Thephotoluminescence(PL)spectrawererecordedonamodelFluoroMax-4spectrofluorometer,whichwasexcitedat240nminthescanningrangeof260-460nm.Thevalence-bandX-rayphotoemissionspectroscopicdata(VB-XPS)wereobtainedonamodelESCALAB250X-rayphotoelectronspectrometerequippedwithanAlKαX-raysourceandthespotsizeof500μm.Atambienttemperature,PODSreactionwasoperatedinabeakerundermagneticallystirring.10mLmodelorrealfuelwasaddedfirstlyintoabeaker,andthensomeamountofCH3OHasanextractant(calculatedinvolumeratiooftheextractanttothefuel),acatalyst(calculatedinthemasspercentinthemodelfuel)andH2O2(calculatedinn(O)/n(S))wereadded.Thebeakerwasplacedinthedarkundermagneticallystirringfor0.5htoestablishadsorption-desorptionequilibriumofDBToncatalysts.PODSproceedunderthevisiblelightirradiationandthesampleswerewithdrawnperiodicallyevery0.5hfromtheupperphase,andthesulfurcontentoftheclearliquidsamplewasdetectedonamodelTSN-5000sulfurnitrogendetectorafterhigh-speedcentrifuge.Catalystwasseparatedfromthereactionmixtureviafiltrationandwashingwithdeionizedethanol,driedat80℃andthendirectlyusedforthenextrun.FourPODSprocesseswererepeated,andineachprocess1.0mmol/Lakindofactiveintermediatecaptureagentwasadded.Isopropanol(IPA),p-benzoquinone(p-BQ)anddisodiumethylenediaminetetraacetate(EDTA-2Na)wereusedfordetectinghydroxylradicals,superoxideradicalsandholes,respectively.ResultsanddiscussionTheXRDpatternsshowthatLa-TiO2/SBA-15retainsatwo-dimensionalhexagonalhighlyorderedmesoporousstructureofSBA-15.TiO2,La-TiO2andLa-TiO2/SBA-15donotshowanycharacteristicdiffractionpeaks,indicatingthattheyallareamorphous.ComparedwiththesampleSBA-15,thespecificsurfacearea,porevolumeandporesizeofsampleLa-TiO2/SBA-15decreaseduetotheloadingofLa-TiO2.However,itsspecificsurfaceareaisstillhigherthanthatofamorphousTiO2.TheTEMimagespresentanorderedmesoporousstructureofLa-TiO2/SBA-15,andLa-TiO2isalsoevenlydispersiveintheporechannels.TheUV-VisanalysisshowsthattheabsorptionedgeofLa-TiO2ishigherthanthatofTiO2.AreasonisthatlanthanumdopingreducesabandgapenergyofTiO2andimprovesalightabsorptionabilityofthecatalyst.Althoughabandgapwidthisalmostunchangedforloading.ThePLspectraindicatethattheintensityoffluorescenceemissionpeakdecreasesafterdopingandloading,provingthatthedopingandloadingbothcanreduceanelectron-holerecombinationrate,therebyprolongingthephotogeneratedcarrierlifetimeofamorphoustitaniamaterial.TheeffectofreactionconditionontheresultsofPODSwasinvestigatedandoptimized.Theresultsareobtainedunderoptimumconditions(i.e.,catalystdosageof1%(inmassfraction),n(O):n(S)of15:1,andtheofagent:oilratioof1:1).Undersuchconditions,thedesulfurizationrateis95.12%,anditcanstillreachmorethan85%afterfourrunsofreusing.ForLa-TiO2/SBA-15asacatalyst,theactiveintermediatespeciesinPODSwere?O2-andh+basedonactiveintermediatespeciescaptureexperiments.ConclusionsLa-TiO2/SBA-15preparedhadatwo-dimensionalhexagonalporestructure,ahighspecificsurfacearea,andwell-dispersion.Lanthanumdopingbroadenedalightresponserange,increasedtheabsorbanceofthelight,andreducedthephotogeneratedelectron-holerecombinationrateofTiO2.La-TiO2/SBA-15hadahighercatalyticactivityratherthanTiO2andLa-TiO2,andagoodreusability.Themainactiveintermediatespecieswere?O2-andh+.
作者：杨丽娜 周效竹 张熙 李剑 Author：YANGLina ZHOUXiaozhu ZHANGXi LIJian
作者单位：辽宁石油化工大学石油化工学院,辽宁抚顺113001中石化大连石油化工研究院有限公司,辽宁大连116000
刊名：硅酸盐学报 ISTICEIPKU
Journal：JournaloftheChineseCeramicSociety
年，卷(期)：2024, 52(7)
分类号：TQ174.75
关键词：镧掺杂二氧化钛 介孔分子筛 负载 光催化氧化脱硫
Keywords：lanthanumdopedtitaniumdioxide mesoporousmolecularsieve loading photocatalyticoxidationdesulfurization
机标分类号：O657.34O4TB383
在线出版日期：2024年7月24日
基金项目：辽宁省教育厅项目，辽宁省教育厅项目，抚顺市科技发展项目负载镧掺杂无定形二氧化钛的介孔光催化氧化脱硫催化剂[
期刊论文] 硅酸盐学报--2024, 52(7)杨丽娜 周效竹 张熙 李剑为了开发高活性油品光催化氧化脱硫催化剂,以样品La-TiO2为活性组分,样品SBA-15为载体合成了以镧掺杂无定形二氧化钛为活性组分的介孔催化剂(La-TiO2/SBA-15),采用X射线衍射(XRD)、X射线荧光光谱(XRF)、氮气吸附-脱附...参考文献和引证文献
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负载镧掺杂无定形二氧化钛的介孔光催化氧化脱硫催化剂 Mesoporous Photocatalytic Oxidation Desulfurization Catalyst for Lanthanum Doped Amorphous Titanium Dioxide
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