简介:CO2capturewithionicliquids(ILs)hasattractedmanyattentions,andmostworksfocusedonabsorptionabilityatambienttemperatures,whileseldomresearchwasconcernedatelevatedtemperatures.ThisnotonlylimitstheCO2absorptionapplicationatelevatedtemperature,butalsothedeterminationoftheoperationconditionoftheCO2desorptiongenerallyoccurringathighertemperature.ThisworkmainlyreportedCO2solubilitiesinILsatelevatedtemperaturesandrelatedpropertieswerealsoprovided.1-alkyl-3-methylimidazoliumbis(trifluoromethylsulfonyl)imide([CnMIm][Tf2N])ILswereselectedasphysicalabsorbentsforCO2captureinthisworkduetotheirrelativehigherCO2absorptioncapacitiesandgoodthermalstabilities.Thelong-termstabilitytestsshowedthat[CnMIm][Tf2N]isthermallystableat393.15Kforlongtime.CO2solubilitiesin[CnMIm][Tf2N]weresystematicallydeterminedattemperaturesfrom353.15Kto393.15K.ItdemonstratedthatCO2solubilityobviouslyincreaseswiththeincreaseofpressurewhileslightlydecreaseswithincreaseoftemperature.Asthelengthofalkylchainonthecationincreases,CO2solubilityinILsincreases.Additionally,thethermodynamicpropertiesincludingtheGibbsfreeenergy,enthalpy,andentropyofCO2werealsocalculated.
简介:ReducingtheanthropogenicCO2emissionsfromfossilresourcecombustionandhumanactivitieshasbecomeoneofthemajorchallengeswearefacingtoday.BeyondthosepracticalapplicationsfortheutilizationofCO2,suchasthesynthesisofsalicylicacid,methanol,urea,NaHCO3-Na2CO3chemicalsandrecentlydevelopedpolycarbonatesynthesis,scientistsarestillseekingnewmaterialsandtechnologiesforefficientcapture,
简介:TheeffortonelectrochemicalreductionofCO2tousefulchemicalsusingtherenewableenergytodrivetheprocessisgrowingfastrecently.Inthisreview,weintroducetherecentprogressesontheelectrochemicalreductionofCO2insolidoxideelectrolysiscells(SOECs).Athightemperature,onlyCOisproducedwithhighcurrentdensitiesandFaradicefficiencywhilethereactoriscomplicatedandabettersealingtechniqueisurgentlyneeded.Thetypicalelectrolytessuchaszirconia-basedoxides,ceria-basedoxidesandlanthanumgallates-basedoxides,anodesandcathodesareintroducedinthisreview,andthecathodematerials,suchasconventionalmetal–ceramics(cermets),mixedionicandelectronicconductors(MIECs)arediscussedindetail.Inthefuture,togainmorevalue-addedproducts,theelectrolyte,cathodeandanodematerialsshouldbedevelopedtoallowSOECstobeoperatedattemperaturerangeof573–873K.Atthosetemperatures,SOECsmaycombinetheadvantagesofthelowtemperaturesystemandthehightemperaturesystemtoproducevariousproductswithhighcurrentdensities.
简介:Wesynthesizedonequaternaryammoniumpolymericionicliquids(PILs)P[VBTHEA]ClandthreeimidazoliumPILsofP[VEIm]Br,P[VEIm]BF4,P[VEIm]PF6byfree-radicalpolymerizationinsolution.ThesePILswerecharacterizedbyFT-IR,1H-NMR,13C-NMR,TGA,XRDandSEM.TheirCO2adsorptioncapacitiesweremeasuredunderdifferentpressuresandtemperaturesbyconstant-volumetechnique.ItwasobservedthatquaternaryammoniumPILsofP[VBTHEA]ClhavehigheradsorptioncapacityforCO2thanthoseimidazoliumPILs,followingP[VBTHEA]Cl>P[VEIm]PF6>P[VEIm]BF4>P[VEIm]Br,whichmaybeascribedtohigherpositivechargedensityonammoniumcationthanthatonimidazoliumcationandthusstrongerinteractionwithCO2,consistentwiththeresultsfromdual-modeadsorptionmodelthatammoniumPILshavemuchhigherCO2bulkabsorptionthanimidazoliumPILs.CO2adsorptioncapacityofP[VBTHEA]Clis9.02mg/gunder295Kand1bar,whichiscomparabletothatofsomeotherPILs,andismuchhigherthanthatofthecorrespondingILsmonomer.ThesePILshavegoodadsorptionselectivityforCO2overN2andregenerationefficiency.
简介:Amine-silicacompositematerialsforpost-combustionCO2capturehaveattractedconsiderableattentionbecauseoftheirhighCO2uptakeatlowCO2concentrations,excellentCO2captureselectivityinthepresenceofmoisture,andlowerenergyrequirementsforsorbentregeneration.Thisreviewdiscussestherecentadvancesinamine-silicacompositesforCO2capture,includingadsorbentpreparationandcharacterization,CO2captureunderdryandmoistureconditionsatdifferentCO2partialpressures,sorbentregeneration,andstabilityaftermanycyclicsorption-desorptionruns.
简介:Inthisstudy,apoly(etherblockamide)(Pebax1657)compositemembraneappliedforCO2capturewaspreparedbycoatingPebax1657solutiononpolyacrylonitrile(PAN)ultrafiltrationmembrane.Ethanol/watermixturewasusedasthesolventofPebaxandtheeffectsofethanol/watermassratiosandPebaxconcentrationonthepermeationpropertiesofcompositemembranewerestudied.Toenhancethecompositemembranepermeance,thegutterlayer,madefromreactiveaminosiliconecrosslinkingwithpolydimethylsiloxane(PDMS),wasdesigned.Theinfluenceofcrosslinkingdegreeofthegutterlayeronmembraneperformancewasinvestigated.Asaresult,aPebax/aminoPDMS/PANmultilayermembranewithhexaneresistancewasdeveloped,showingCO2permeanceof350GPUandCO2/N2selectivityover50.Theblendofpolyethyleneglycoldimethylether(PEG-DME)withPebaxascoatingmaterialwasstudiedtofurtherimprovethemembraneperformance.AfterbeingcombinedwithPEG-DMEadditive,CO2permeanceofthefinalPebax-PEG-DME/amino-PDMS/PANcompositemembranereached400GPUabovewithCO2/N2selectivityover65.
简介:CO2methanationhasbeenahottopicbecauseofitsimportantapplicationinthespacecraftandpotentialutilizationofcarbondioxide.Nickelcatalystisactiveforthisreaction.However,itsactivitystillneedstobeimproved.Dielectricbarrierdischarge(DBD)plasma,initiatedatambientconditionandoperatedat~150°C,hasbeenemployedinthisworkfordecompositionofnickelprecursortoprepareNi/MgAl2O4.Theplasmadecompositionresultsinhighdispersion,uniquestructure,enhancedreducibilityofNiparticlesandpromotedcatalyst-supportinteraction.AnimprovedactivityofCO2methanationwithahigheryieldofmethanehasbeenachievedovertheplasmadecomposedcatalyst,comparedtothecatalystpreparedthermally.Forexample,themethaneyieldoftheplasmapreparedcatalystis71.8%at300°Cbutitis62.9%overthethermalpreparedcatalyst.ThecatalystcharacterizationconfirmedthatCO2methanationovertheDBDplasmapreparedcatalystfollowspathwayofCOmethanation.
简介:Co-electrolysisofCO2andH2Ousinghigh-temperaturesolidoxideelectrolysiscells(SOECs)intovaluablechemicalshasattractedgreatattentionsrecentlyduetothehighconversionandenergyefficiency,whichprovidesopportunitiesofreducingCO2emission,mitigatingglobalwarmingandstoringintermittentrenewableenergies.AsingleSOECtypicallyconsistsofanionconductingelectrolyte,ananodeandacathodewheretheco-electrolysisreactiontakesplace.Thehighoperatingtemperatureanddifficultactivatedcarbon-oxygendouble-bondofCO2putforwardstrictrequirementsforSOECcathode.Greateffortsarebeingdevotedtodevelopsuitablecathodematerialswithhighcatalyticactivityandexcellentlong-termstabilityforCO2/H2Oelectro-reduction.Thesofarcathodematerialdevelopmentisthekeypointofthisreviewandalternativestrategiesofhigh-performancecathodematerialpreparationisproposed.UnderstandingthemechanismofCO2/H2Oelectro-reductionisbeneficialtohighlyactivecathodedesignandoptimization.Thusthepossiblereactionmechanismisalsodiscussed.Especially,amethodincombinationwithelectrochemicalimpedancespectroscopy(EIS)measurement,distributionfunctionsofrelaxationtimes(DRT)calculation,complexnonlinearleastsquare(CNLS)fittingandoperandoambientpressureX-rayphotoelectronspectroscopy(APXPS)characterizationisintroducedtocorrectlydisclosethereactionmechanismofCO2/H2Oco-electrolysis.Finally,differentreactionmodesoftheCO2/H2OcoelectrolysisinSOECsaresummarizedtooffernewstrategiestoenhancetheCO2conversion.Otherwise,developingSOECsoperatingat300-600°CcanintegratetheelectrochemicalreductionandtheFischer-TropschreactiontoconverttheCO2/H2Ointomorevaluablechemicals,whichwillbeanewresearchdirectioninthefuture.
简介:Wereportedabifunctionalmaterial,Cr-salenimplantedconjugatedmicroporouspolymer(Cr-CMP),whichisabletocaptureexcellentCO2amountsandhasaremarkablecatalyticactivitytowardsthecycloadditionreactionofCO2toepoxidesformingcycliccarbonatesatmildconditionswithoutadditionalsolvents.ThisheterogeneousCr-CMPcatalysthasasuperiorcatalyticactivitytoitsrelatedhomogeneouscatalystandcanbereusedmorethantentimeswithoutasignificantdecreaseincatalyticactivity.
简介:Recentadvancesontheuseofnanocarbon-basedelectrodesfortheelectrocatalyticconversionofgaseousstreamsofCO2toliquidfuelsarediscussedinthisperspectivepaper.Anovelgas-phaseelectrocatalyticcell,differentfromthetypicalelectrochemicalsystemsworkinginliquidphase,wasdeveloped.Thereareseveraladvantagestoworkingasphase,e.g.noneedtorecovertheproductsfromaliquidphaseandnoproblemsofCO2solubility,etc.Operatingundertheseconditionsandusingelectrodesbasedonmetalnanoparticlessupportedovercarbonnanotube(CNT)typematerials,longC-chainproducts(inparticularisopropanolunderoptimizedconditions,butalsohydrocarbonsuptoC8-C9)wereobtainedfromthereductionofCO2.Pt-CNTaremorestableandgiveinsomecasesahigherproductivity,butFe-CNT,particularusingN-dopedcarbonnanotubes,giveexcellentpropertiesandarepreferabletonoble-metal-basedelectrocatalystsforthelowercost.ThecontrolofthelocalizationofmetalparticlesattheinneroroutersurfaceofCNTisanimportactfactorfortheproductdistribution.ThenatureofthenanocarbonsubstratealsoplaysarelevantroleinenhancingtheproductivityandtuningtheselectivitytowardslongC-chainproducts.TheelectrodesfortheelectrocatalyticconversionofCO2arepartofaphotoelectrocatalytic(PEC)solarcellconcept,aimedtodevelopknowledgeforthenewgenerationartificialleaf-typesolarcellswhichcanusesunlightandwatertoconvertCO2tofuelsandchemicals.TheCO2reductiontoliquidfuelsbysolarenergyisagoodattempttointroducerenewablesintotheexistingenergyandchemicalinfrastructures,havingahigherenergydensityandeasiertransport/storagethanothercompetingsolutions(i.e.H2).
简介:Accuratelymeasuringthedifferentialmolecularabsorptioncrosssectionisthekeytoobtainingahigh-precisionconcentrationofatmospherictracegasesinadifferentialabsorptionlidar(DIAL)system.However,theCO2absorptionlineismeticulousat1.6μm,easilytranslatingandbroadeningbecauseofthechangeoftemperatureandpressure.Hence,measuringtheverticalprofileofatmospherictemperatureandpressuretocalculatetheverticalprofileoftheCO2weightparameterisnecessary.Ingeneral,measuringatmospherictemperatureandpressurehasacertainamountofuncertainty.Therefore,thisstudyproposestheconceptofabalancedon-linewavelength,wherethedifferentialmolecularabsorptioncrosssectionislargerandtheCO2weightparameterisinsensitivetotheuncertaintyofatmospherictemperatureandpressure.Inthisstudy,weanalyzedtheinfluenceofuncertaintyontheCO2weightparameterateverypreselectedwavelength,aswellasdeterminedanappropriatewavelengthnearoneoftheabsorptionpeaks.Ourresultshowsthat1572.023nmshouldbeoneoftheappropriatebalancedonlinewavelengths.ThemeasurementerrorsofthemixingratioofCO2moleculeinthiswavelengthareonly0.23%and0.25%andarecausedby1Ktemperatureerrorand1hPapressureerror,respectively.Thisachievementofabalancedon-linewavelengthwillnotonlydepresstherequirementofthelaser’sfrequencystabilizationbutalsothedemandformeasurementprecisionoftheatmospherictemperatureandpressureprofile.Furthermore,thisstudycanachievetheexactmeasurementoftheverticalprofileofatmosphericCO2basedonanindependentdifferentialabsorptionlaser.
简介:TogaindeepinsightintotheMorphologicaleffectofNixMg1-xOcatalystsonthereactionofCO2reformingwithmethane,wedesignedandfabricatedthreedifferentspatialstructuralNixMg1-xOcatalysts.TheseNixMg1-xOcatalystswithspecificmodelssuchasrod,sheetandsphere,exhibitedvariousactivityandstabilityinCO2reformingreaction.HereinNixMg1-xOnanorodsdisplayedhighercatalyticactivity,inwhichmethaneconversionwasupto72%andCO2conversionwas64%at670°Cwithaspacevelocityof79,200mL/(gcath),comparedwithnanosheetandnanospherecounterparts.Furthermore,bothcatalystsofNixMg1-xOnanorodandnanosheetshowedahighresistancetowardcokedepositionandsinteringofactivesitesintheprocessofCO2reformingofmethane.
简介:FifteennewabsorptionlinesareobservedwhenstudyingCO2absorptionspectroscopybywavelengthmodulation(WM)techniquewithadistributedfeedbacklaser.TheovertonespectraofCO2around1.31μmandthecorrespondingspectralparameters(i.e.positions,intensities,self-broadeningcoefficients)arepresented.Theintensityoftheweakestlinedetectedis2.25163×10^-27cm^-1/(molecule·cm^-2)atthepressureof5Tort,withacorrespondingabsorptionof3.88×10^-8.
简介:CO2photoreductionisanattractiveprocesswhichallowsthestorageofsolarenergyandsynthesisofsolarfuels.Manydifferentphotocatalyticsystemshavebeendeveloped,whilethealternativephoto-reactorsarestillinsufficientlyinvestigated.Inthiswork,photoreductionofCO2withH2OintoCH4wasinvestigatedinamodifiedconcentratingsolarreactor,usingTiO2andPt/TiO2asthecatalysts.TheTiO2andPt/TiO2sampleswereextensivelycharacterizedbydifferenttechniquesincludingpowderX-raydiffraction(XRD),N2adsorption/desorptionandUV–visabsorption.ThecatalyticperformanceoftheTiO2andPt/TiO2samplesinthegasphasewasevaluatedunderunconcentratedandconcentratedXe-lamplightandnaturesolarlightwithdifferentconcentratingratios.VariousparametersofthereactionsystemandthecatalystswereinvestigatedandoptimizedtomaximizethecatalyticperformanceofCO2reductionsystem.Comparedwiththenormallightirradiation,theTiO2andPt/TiO2samplesshowhigherphotocatalyticactivity(about6–7times)forreducingCO2intoCH4underconcentratedXe-lamplightandnaturesolarlight.Intherangeofexperimentallightintensity,itisfoundthattheconcentrationofthelightmakesitsuitableforthecatalyticreaction,andincreasestheutilizationefficiencyoftheTiO2andPt/TiO2sampleswhiledoesnotdecreasethequantumefficiency.
简介:Inthiswork,a2Dcovalenttriazine-basedframeworkwaspreparedbyusing1,3-dicyanobenzo[c]thiophene(DCBT)asmonomertoeffectivelycaptureCO2.TheresultingCTF-DCBTwascharacterizedbyFT-IR,XPS,PXRD,elementalanalysis,SEM,TEM,andN2adsorption-desorption.TheresultsindicatethatCTF-DCBTispartiallycrystallineandhasultramicropore(6.5A?)aswellashighheteroatomcontents(11.24wt%and12.61wt%forNandS,respectively).Inaddition,theBETsurfaceareaandtotalporevolumeofCTF-DCBTare500m2/gand0.26cm3/g,respectively.CTF-DCBTpossessesexcellentthermalstability(450°C)andchemicalstabilitytowardsboilingwater,4MHCl,and1MNaOH.TheCO2adsorptioncapacityofCTF-DCBTis37.8cm3/gat1barand25°C.Aftersixadsorption-desorptioncycles,thereisnoobviouslossofCO2uptakeobserved.Duetotheultramicroporeandhighheteroatomcontents,CTF-DCBThashighisostericheatsofadsorptionforCO2andhighselectivitiesofCO2overN2andCH4.At25°C,theCO2/N2andCO2/CH4selectivitiesare112.5and10.3,respectively,whicharehigherthanthoseofmostPOFs.BreakthroughcurvesindicatethatCTF-DCBTcouldeffectivelyseparateCO2/N2andCO2/CH4mixtures.
简介:CO2conversionviaphotocatalysisisapotentialsolutiontoaddressglobalwarmingandenergyshortage.PhotocatalysiscandirectlyutilizetheinexhaustiblesunlightasanenergysourcetocatalyzethereductionofCO2tousefulsolarfuelssuchasCO,CH4,CH3OH,andC2H5OH.Amongstudiedformulations,CubasedphotocatalystsarethemostattractiveforCO2conversionbecausetheCu-basedphotocatalystsarelow-costandabundancecomparingnoblemetal-basedcatalysts.Inthisliteraturereview,acomprehensivesummaryofrecentprogressonCu-basedphotocatalystsforCO2conversion,whichincludesmetalliccopper,copperalloynanoparticles(NPs),copperoxides,andcoppersulfidesphotocatalysts,canbefound.Thisreviewalsoincludedadetaileddiscussiononthecorrelationsofmorphology,structure,andperformanceforeachtypeofCu-basedcatalysts.Thereactionmechanismsandpossiblepathwaysforproductionsofvarioussolarfuelswereanalyzed,whichprovideinsightintothenatureofpotentialactivesitesforthecatalysts.Finally,thecurrentchallengesandperspectivefutureresearchdirectionswereoutlined,holdingpromisetoadvanceCu-basedphotocatalystsforCO2conversionwithmuch-enhancedenergyconversionefficiencyandproductionrates.
简介:Aseriesofamine-basedadsorbentsweresynthesizedusingsiliceousMCM-41individuallyimpregnatedwithfourdifferentamines(ethylenediamine(EDA),diethylenetriamine(DETA),tetraethylenepentamine(TEPA)andpentaethylenehexamine(PEHA))tostudytheeffectofaminechainlengthandloadingweightontheirCO2adsorptionperformancesindetail.TheadsorbentswerecharacterizedbyFT-IR,elementalanalysis,andthermo-gravimetricanalysistoconfirmtheirstructureproperties.Thermo-gravimetricanalysiswasalsousedtoevaluatetheCO2adsorptionperformanceofadsorbents.Longerchainamine-basedmaterialscanachievehigheramineloadingsandshowbetterthermalstability.TheCO2adsorptioncapacitiesatdifferenttemperaturesindicatethattheCO2adsorptionisthermodynamicallycontrolledoverEDAMCM41andDETA-MCM41,whiletheadsorptionoverTEPA-MCM41andPEHA-MCM41isunderkineticcontrolatlowtemperature.ThechainlengthofaminesaffectstheCO2adsorptionperformanceandtheadsorptionmechanismsignificantly.TheresultsalsoindicatethatCO2adsorptioncapacitycanbeenhanceddespiteofhighoperationtemperatures,ifappropriateamines(TEPAandPEHA)areapplied.However,adsorbentswithshortchainamineexhibithigheradsorptionanddesorptionratesduetothecollaborativeeffectofrapidreactionmechanismsofprimaryaminesandlessdiffusionresistanceofshorterchainlengthamines.