简介：Catalystplaysanimportantroleindirectcolaliquefaction(DCL)^[1],Duetorelativelyhighactivity,lowcostandenvironmentallybenignfordisposal,ironcatalystsareregardedasthemostattractivecatalystsforDCL.Tomaximizecatalyticeffectandminimizecatalystusage,ultra-finesizecatalystsarepreferred.Themosteffectivecatalystsarefoundtobethoseimpregnatedontocoalbecauseoftheirhighdispersiononcoalsurfaceandintimatecontactwithcoalparticles.

简介：Phosphorylatedmesoporouscarbons(PMCs)wereinvestigatedascatalystsinthedehydrationoffructosetohydroxymethylfurfural(HMF).TheacidicPMCsshowbetterselectivitytoHMFcomparedtosulfonatedcarboncatalyst(SC)despiteloweractivity.TheconcentrationofP-OgroupsonthePMCwascorrelatedwiththeactivity/selectivityofthecatalysts;thehighertheP-Oconcentration,thehighertheactivity.However,thehighertheP-Ocontent,thelowertheselectivitytoHMF.Indeed,alowerconcentrationoftheP-OgroupsminimizedthedegradationofHMFtolevulinicacidandtheformationofby-products,suchashumines.Stabilitytestsshowedthatthesesystemsdeactivateduetotheformationofhuminesandwaterinsolubleby-productsderivedfromthedehydrationoffructosewhichblockedthecatalyticallyactivesites.

简介：TheeffectofacidcomponentincludingvariousconventionalacidsandtungsticcompoundsonglucosehydrogenationoveraseriesofbinarycatalystsystemcontainingRu/Ccatalystwasinvestigated.TheresultsshowedthatHCl,H2SO4,H3BO3,H3PO4,andHNO3hadnegligibleeffect,whileallthetungsticcompoundsimposedinhibitingeffectsonthehydrogenationofglucoseoverRu/Ccatalyst,andthesuppressingeffectfollowedtheorderofH2WO4>HPW>WO3>AMT>HSiW.Thisorderisthesameastheorderofethyleneglycol(EG)yieldsintheone-potconversionofglucosetoEG,suggestingtheimportantroleofcompetitionbetweenglucosehydrogenationandretro-aldolcondensationincontrollingtheselectivityofEG.

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简介：Glycerolcanbeobtainedasaby-productduringbiodieselmanufacture.Itisimportanttoconvertglyceroltovalue-addedproducts.Glycerolesterificationwithaceticacidisoneofthemostpromisingapproachesforglycerolutilization.Itisusuallydifficulttoobtaindiacetinwithgoodactivityandselectivity.Inthiswork,glycerolesterificationwithaceticacidoverdifferentmetaloxides,suchasBi2O3,Sb2O3,SnO2,TiO2,Nb2O5andSb2O5,wasinvestigated.Itwasfoundthatinthesixinvestigatedmetaloxides,onlySb2O5resultedingoodactivityandselectivitytodiacetin.Undertheoptimizedconditions,theglycerolconversionreached96.8%,andtheselectivitytodiacetinreached54.2%,whiletheselectivitytomonoacetinandtriacetinwas33.2%and12.6%,respectively.ThecatalystswerecharacterizedwithFT-IRspectraofadsorbedpyridine,whichindicatedthatinthesixinvestigatedmetaloxides,onlySb2O5possessedBr?nstedacidsitesstrongenoughtoprotonateadsorbedpyridine.ThegoodcatalyticactivityandselectivitytodiacetinmightbemainlyattributabletotheBr?nstedacidsitesofSb2O5.ReusabilitytestsshowedthatwithSb2O5ascatalyst,aftersixreactioncycles,nosignificantchangeintheglycerolconversionandtheselectivitytodiacetinwasobserved.

简介：Catalyticcombustionofpropane-airmixturewasinvestigated.Platinumcatalystsoveraflatstainlesssteelwithγ-aluminawashcoatwereemployed.Theemployedburnerhasthreecatalystssetparalleltothemixtureflow,spacedatanintervalof5,10and15mm.Bothexperimentandnumericalsimulationweremadeatinlettemperatureof553K,inletvelocityof3to7m/sandequivalenceratioof0.3to0.5.Inthenumericalsimulation,two-dimensional,steadystatemodelwasdevelopedtocalculatethetemperatureandspeciesconcentrationingas-phase.Inthismodel.chemicalreactiononthecatalystsurfaceandthatinthegasphasewereassumedtooccurinthree-steps.Thenumericalresultsshowgoodagreementwithexperimentalresults.Itwasfoundthatthepropertiesofthecatalyststronglyaffectthecatalystsurfacetemperature.Especially,thethermalconductivityofcatalysthasagreateffect,whiletheemissivityofcatalysthaslesseffect.

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简介：ZSM-48zeoliteswithvariousSi/AlratioswerehydrothermallysynthesizedintheH2N（CH2）6NH2（HDA）-containingmedia.TheobtainedsampleswerehighlycrystallizedwithminormixedphasesasevidencedbyX-raypowderdiffraction（XRD）.ThealkalinetreatedZSM-48zeolitesmaintaineditsstructureunderdifferentconcentrationsofNaOHaqueoussolution.Microporesremainedunchangedwhilemesoporeswithwideporesizedistributionformedafterthealkalinetreatment.Thesurfaceareaincreasedfrom228to288m2/g.TheBr?nstedacidsiteshadlittlealterationwhileanobviousincreaseofLewisacidsiteswasobserved.Thehydroisomerizationofhexadecanewasperformedasthemodelreactiontotesttheeffectsofthealkalitreatment.Theconversionofhexadecanehadalmostnochange,whichwasattributedtothepreservationoftheBr?nstedacidsites.Whilehighselectivitytoiso-hexadecanewithanimprovedisotonormalratioofalkaneswasduetothemesoporeformationandimproveddiffusivity.

简介：Directelectrochemicalformationofhydrogenperoxide(H2O2)frompureO2andH2oncheapmetal-freeearthabundantcatalystshasemergedasthehighestatom-efficientandenvironmentallyfriendlyreactionpathwayandisthereforeofgreatinterestfromanacademicandindustrialpointofview.Veryrecently,novelmetal-freemesoporousnitrogen-dopedcarboncatalystshaveattractedlargeattentionduetotheuniquereactivityandselectivityfortheelectrochemicalhydrogenperoxideformation[1–3].Inthiswork,weprovidedeeperinsightsintotheelectrocatalyticactivity,selectivityanddurabilityofnovelmetal-freemesoporousnitrogen-dopedcarboncatalystfortheperoxideformationwithaparticularemphasisontheinfluenceofexperimentalreactionparameterssuchaspHvalueandelectrodepotentialforthreedifferentelectrolytes.Weusedtwoindependentapproachesfortheinvestigationofelectrochemicalhydrogenperoxideformation,namelyrotatingring-diskelectrode(RRDE)techniqueandphotometricUV–VIStechnique.Ourelectrochemicalandphotometricresultsclearlyrevealedaconsiderableperoxideformationactivityaswellashighcatalystdurabilityforthemetal-freenitrogen-dopedcarboncatalystmaterialinbothacidicaswellasneutralmediumatthesameelectrodepotentialunderambienttemperatureandpressure.Inaddition,theobtainedelectrochemicalreactivityandselectivityindicatethatthemechanismsfortheelectrochemicalformationanddecompositionofperoxidearestronglydependentonthepHvalueandelectrodepotential.

简介：APt-MoO3/Ccatalyst,aimedtoeliminatetheharmfuleffectofsulfurdioxide（SCb）ontheperformanceofPtnanoparticles（NPs）forcatalysisofoxygenreductionreaction（ORR）inprotonexchangemembranefuelcells（PEMFC）,isdevelopedandcharacterizedbyTEM,XRDandXPS.TheresultsrevealthatPt-MoO3/Ccatalystexhibitsnotonlyahighercatalyticactivity,butalsoabetterSO2poisoningresistanceandabetterrecoveryperformancethanthecommercialPt/Ccatalystdoes.

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简介：Anenvironmentallyfriendlyprecursor,adenosine,hasbeenusedasadualsourceofCandNtosynthesizenitrogen-dopedcarboncatalystwith/withoutFe.Ahydrothermalcarbonizationmethodhasbeenusedandwateristhecarbonizationmedia.Themorphologyofsampleswith/withoutFecomponenthasbeencomparedbyHRTEM,andtheresultshowsthatFecanpromotethegraphitizationofcarbon.Furtherelectro-chemicaltestshowsthattheoxygenreductionreaction(ORR)catalyticactivityofFe-containingsample(C–FeN)ismuchhigherthanthatoftheFe-freesample(C–N).Additionally,theintermediatesofC–FeNformedduringeachsyntheticprocedurehavebeenthoroughlycharacterizedbymultiplemethods,andthefunctionofeachprocedurehasbeendiscussed.TheC–FeNsampleexhibitshighelectro-catalyticstabilityandsuperiorelectro-catalyticactivitytowardORRinalkalinemedia,withitshalf-wavepotential20mVlowerthanthatofcommercialPt/C(40wt%).Itisfurtherincorporatedintoalkalinepolymerelectrolytefuelcell(APEFC)asthecathodematerialandledtoapowerdensityof100mW/cm~2.

简介：PtRu/SnO2/Ccatalystwaspreparedinapolyolprocess,followedbyreductiontreatmentandalkalineetching.X-raydiffraction,transmissionelectronmicroscopewithenergydispersivespectrometerandXrayphotoelectronspectroscopywereusedtocharacterizethemorphology,structureandcompositionofthecatalysts.COandmethanolelectro-oxidationactivitiesofthecatalystswereevaluatedbyCOstrippingvoltammetry,cyclicvoltammetryandchronoamperometrymeasurements.ReductiontreatmentofthepreparedPtRuSnO2/CcatalystinapolyolprocessinducedtheenrichmentofSnonthesurface,inhibitingmethanoldissolutionandCOadsorptiononPt.AlkalineetchingremovedSnorSnOxandthusexposedPtRuonthesurface,resultinginenhancedactivitiesforCOandmethanolelectro-oxidationduetothesynergyeffectsofPtRuonthesurfaceandSnspeciesbeneath.

简介：ThedetailedkineticsofFischer-TropschsynthesisoveranindustrialFe/Cu/La/Sicatalystwasstudiedinacontinuousspinningbasketreactorundertheconditionsrelevanttoindustrialoperations.ReactionrateequationswerederivedonthebasisofLangmuir-HinshelwoodHougen-WatsontypemodelsforFischer-Tropschsynthesisbasedonpossiblereactionssetsoriginatedfromthecarbide,enolicandcombinedenol/carbidemechanisms.Kineticmodelcandidateswereevaluatedbytheglobaloptimizationofkineticparameters,whichwererealizedbyfirstminimizationofmulti-responseobjectivefunctionswithconventionalLevenberg-Marquardtmethod.Itwasfoundthatanenolicmechanismbasedmodelcouldproduceagoodfitoftheexperimentaldata.Theactivationenergyforparaffinformationis95kJmol-1whichissmallerthanthatforolefinformation(121kJmol-1).

简介：BimetallicFe-Mnnanocatalystssupportedoncarbonnanotubes(CNTs)werepreparedusingmicroemulsiontechniquewithwater-to-surfactantratiosof0.4-1.6.ThenanocatalystswereextensivelycharacterizedbydifferentmethodsandtheiractivityandselectivityinFischer-Tropschsynthesis(FTS)havebeenassessedinafixed-bedmicroreactor.Thephysicochemicalpropertiesandperformanceofthenanocatalystswerecomparedwiththecatalystpreparedbyimpregnationmethod.Verynarrowparticlesizedistributionhasbeenproducedbythemicroemulsiontechniqueatrelativelyhighloadingofactivemetal.TEMimagesshowedthatsmallmetalnanoparticlesintherangeof3–7nmwerenotonlyconfinedinsidetheCNTsbutalsolocatedontheoutersurfaceoftheCNTs.Usingmicroemulsiontechniquewithwatertosurfactantratioof0.4decreasedtheaverageironparticlesizesto5.1nm.Thereductionpercentageanddispersionpercentagewerealmostdoubled.Activityandselectivitywerefoundtobedependentonthecatalystpreparationmethodandaverageironparticlesize.COconversionandFTSrateincreasedfrom49.1%to71.0%and0.144to0.289gHC/(gcath),respectively.WhiletheWGSratedecreasedfrom0.097to0.056gCO2/(gcath).C5+liquidhydrocarbonsselectivitydecreasedslightlyandolefinsselectivityalmostdoubled.

简介：Sn-dopedTiO_2nanoparticleswithhighsurfaceareaof125.7m~2·g~(-1)aresynthesizedviaasimpleone-stephydrothermaimethodandexploredasthecathodecatalystsupportforprotonexchangemembranefuelcells.ThesynthesizedsupportmaterialsarestudiedbyX-raydiffractionanalysis,energydispersiveX-rayspectroscopyandtransmissionelectronmicroscopy.Itisfoundthattheconductivityhasbeengreatlyimprovedbytheadditionof30mol%SnandPtnanoparticlesarewelldispersedonTi_(0.7)Sn_(0.3)O_2supportwithanaveragesizeof2.44run.ElectrochemicalstudiesshowthattheTi_(0.7)Sn_(0.3)O_2nanoparticleshaveexcellentelectrochemicalstabilityunderahighpotentialcomparedtoVulcanXC-72.Theas-synthesizedPt/Ti_(0.7)Sn_(0.3)O_2exhibitshighandstableelectrocatalyticactivityfortheoxygenreductionreaction.ThePt/Ti_(0.7)Sn_(0.3)O_2catalystreservesmostofitselectrochemicallyactivesurfacearea(ECA),anditshalfwavepotentialdifferenceis11mV,whichislowerthanthatofPt/XC-72(36mV)under10hpotentialholdat1.4Vvs.NHE.Inaddition,theECAdegradationofPt/Ti_(0.7)Sn_(0.3)O_2is1.9timeslowerthancommercialPt/XC-72under500potentialcyclesbetween0.6Vand1.2Vvs.NHE.Therefore,theassynthesizedPt/Ti_(0.7)Sn_(0.3)O_2canbeconsideredasapromisingalternativecathode,catalystforprotonexchangemembranefuelcells.

简介：Trimetallicpalladium-copper-cobaltnanoparticlessupportedonreducedgrapheneoxide(PdCuCo/RGO)withdifferentmolarratiosofPd,CuandCocanbesynthesizedbyfacilechemicalreductionwithNaBH4asreductantandcetrimoniumbromideasstabilizer.Themorphology,structureandcompositionoftheas-synthesizedcatalystsarecharacterizedbytransmissionelectronmicroscopy,X-raydiffractionandXrayphotoelectronspectroscopy.Thecyclicvoltammetryandchronoamperometryareutilizedtoinvestigatetheelectrochemicalactivitiesandstabilitiesoftheas-obtainedcatalysts.TheresultsdemonstratethatthePdCuCo/RGOcatalystshowssuperiorcatalyticactivityandstabilityformethanolelectrooxidationinalkalinemediacomparedwithPdCu/RGO,PdCo/RGO,andPd/RGOcatalysts.ThesefindingssuggestthatthePdCuCo/RGOcatalystpossessesagreatpotentialasapromisinganodecatalystfordirectmethanolfuelcells.

简介：研究了ＹＢａＣｕ３Ｏ６～７超导催化剂上ＣＯ２的加氢制醇反应。考察了温度、压力和空速等条件对催化剂反应性能的影响。反应的主要产物是甲醇、ＣＯ和少量甲醚。利用ＸＰＳ、ＸＲＤ和ＡＦＭ等技术对催化剂的结构、铜的存在状态和反应活性位进行表征发现，在反应过程中，ＹＢａ２Ｃｕ３Ｏ６～７由ｏｒｔｈｏｍｂｉｃ相转变为ｔｅｔｒａｇｏｎａｌ相。反应活性位可能是Ｃｕ（Ｉ）物种。反应后催化剂颗粒的分散程度明显提高