简介:利用线性伏安法和恒电流电解法研究了苯酚在Ti/PbO2电极上的电催化氧化反应,通过电氧化过程中反应物和中间物的高效液相色谱测定,研究了苯酚在Ti/PbO2电极上电催化氧化的反应机理.实验发现,Ti/PbO2电极对水溶液中苯酚的电氧化具有显著的催化作用,25℃时,对初始浓度为2mmol/L的苯酚水溶液,恒定电流密度为50mA/cm2,电解3h,苯酚转化率为98.02%,有机碳去除率为54.36%.苯酚在Ti/PbO2电极上电催化氧化要经过对苯二酚或邻苯二酚、对苯醌、反丁烯二酸和草酸,最终变成二氧化碳和水的历程.第一步反应苯酚转化的主产物是对苯二酚.对苯二酚转化为苯醌和苯醌转化为反丁烯二酸的反应为慢反应,反丁烯二酸转化为草酸的反应为快反应.
简介:NanocrystallineanataseTiO2filmswithindiumtinoxide(ITO)coatedglassasthefilmsubstratewerefabricatedthroughspin-coatingtechnique.TheTiO2pasteswerepreparedwithsodiumdodecylbenzenesulfonate(DBS)modifiedTiO2nanocrystals,synthesizedbysol-hydrothermalprocessesinadvance,togetherwithdifferentamountsofpolyethyleneglycol(PEG)macromolecules.Theas-preparedfilmsweremainlycharacterizedbyultraviolet-visible(UV-Vis)spectroscopy,fieldemissionscanningelectronmicroscopy(FE-SEM)andwatercontactangle(WCA)measurement.EffectsoftheadditionofDBSandPEGonthewettingperformanceoftheresultingfilmsandrelevantmechanismswereprincipallyinvestigated.Theresultsshowthattheas-preparedfilmdisplayssuper-hydrophilicpropertyafterco-additionofDBSandPEGalthoughitisnotexposedtoultravioletlightpriortotheWCAmeasurement.Thisappealingresultismainlyattributedtotheproducedmicroandnanometer-scalehierarchicalsurfacestructurewithuniformlydispersedmicropapillae.EachpapillawasmadeupofagreatnumberofTiO2nanoparticles.ThepossibleformationmechanismsrelatedtotheDBSamphiphilicpropertyofthecharacteristicsurfacewerealsosuggested.Moreover,theresultingfilmalsoexhibitsconsiderabledurabilityinthesuperhydrophilicity,whichisveryusefulforpracticalapplicationinself-cleaning,anti-fogging,andbacteria-resistantfields.
简介:Inamixedsolventofaceticacid(AcOH)/water,methylenediphenyldicarbamate(MDC)wassynthesizedbythecondensationofmethylphenylcarbamate(MPC)andformaldehydeinthepresenceofaninorganicacidcatalyst.BasedonthedifferentsolubilitiestoMPCandMDC,themixedsolventshowedhighercatalyticperformancethanpurewater.ThemixedsolventnotonlypromotedthecondensationofMPCbutasloexhibitedtheadvantageoftheproductseparationwiththereactants.Undertheoptimizedconditions:aH_2SO_4massfractionof31%,areactiontemperatureof95℃andreactiontimeof3.5h,theyieldofMDCreached74.3%.Inaddition,therecycleofthesolventwasalsoinvestigated.
简介:IntroductionTheelectrochemicalreductionofO2wasinvestigatedwidelyduringthepasttwodecades.O2-canreactwithvariousorganiccompounds.O2-asanewsynthesisreagenthasbeenbeingexplored.
简介:STUDYONTHEREARRANGEMENTREACTIONOF5-AMINO-1-AMINOCARBONYL-1,2,ANDITSANALOGUES¥RongJianLU;HuaZhengYANG;BaoYingQIAN;HaiYanDENG(N...
简介:Twocalix[4]arenederivativescontaining1,2,3-triazolemoietyweresynthesizedviaK2CO3-catalyzed1,3-dipolarcycloadditionreactionbetweencalix[4]arene-basedazideandactivemethylenecompoundsingoodyields.Thestructuresofthetwocompoundssynthesizedhereinwerefullyconfirmedby1HNMR,,13CNMR,andMS(ESI).Thethermalanalysisshowedthatthemasslossesofthesynthesizedcompounds4and5containing1,2,3-triazolegroupsaresimilartoeachother.
简介:用量子化学B3LYP/6-311+G(d,p)方法优化了H2ClCS单分子分解反应驻点物种的几何构型,并在相同水平上通过频率计算和内禀反应坐标(IRC)分析对过渡态结构及连接性进行了验证.用QCISD(T)/6-311++G(d,p)方法计算各物种的单点能,并对总能量进行了零点能校正.利用经典过渡态理论(TST)与变分过渡态理论(CVT)并结合小曲率隧道效应模型(SCT),计算了主反应通道在200K~2000K温度范围内的速率常数kTST,kCVT和kCVT/SCT.结果表明,H2ClCS存在8条可能的裂解通道,可生成产物P1(HCS+HCl),P2(CSH+HCl),P3(H2S+CCl)和P4(ClHCS+H).所有反应均为吸热反应.相对于H2ClCS,各产物能量分别为60.9,222.9,275.7和156.9kJ.mol-1.通道H2ClCS→TS3→P1的反应势垒为81.5kJ.mol-1,是标题反应的主反应通道,其余通道为次反应通道.在200K~2000K温度区间内得到主反应通道的表观反应速率常数三参数表达式为.kCVT/SCT=8.7610T0.79exp(-4053.6/T)s-1.
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简介:Aseriesofcopper(Ⅱ)complexeswithpyridineN-oxide-2-ylmethylidened-ithiocarbazatesasligandsweresynthesizedandcharacterizedbyIRspectra,electronicspectraandmagneticmomentsmeasurementatroomtemperature.Variabletemperaturemagneticsusceptibilites(3-300K)offourcomplexsweremeasuredandfittedwiththeBleaney-Bowersdimerequationbyconsideringthemagneticinteractionbetweenmolecules.Thefittingresultsshowtheexistenceofintramolecularferromagneticinteractionsandintermolecu-laranti-ferromagneticinteractionsinthesecopper(Ⅱ)complexes.
简介:SYNTHESISOF3-ARYL-1(2H,4H)ACRIDONESANDTHEIRDERIVATIVES¥RongYIN;GuangFanHAN;YuTianLI(DepartmentofMedicalLaboratory,JilinMediea...
简介:Theimportantintermediateforsynthesesofvariousanti-HIVnucleosideanalogues,methyl2,3-dideoxy-3-fluoro-6-O-(p-methylbenzoyl)-a-D-ribofuranoside,wassynthesizedstartingfrom2-deoxy-D-ribosein5stepswithanoverallyieldof24%.Thisstrategycanbealsousedforsynthesizingotheranalogueswithvarioussubstitutionsat3-Cposition.
简介:利用密度泛函理论(DensityFunctionalTheory)中的B3LYP方法在6-311+G(d,p)的计算水平上研究了Fe/Fe_2与NO反应的相关微观机理.全参数优化了Fe+NO和Fe_2+NO反应体系在不同重态反应势能面上各驻点的几何结构,并用频率分析法以及内禀反应坐标(IntrinsicReactionCoordinate)方法对过渡态进行了验证,得到了相对应的反应的微观反应路径.用"两态反应"分析反应机理,计算结果表明2个体系的优先选择路径均为低自旋态进入和高自旋态离开反应.通过对2个体系反应活化能的比较,Fe_2+NO体系更易进行.
简介:Li0.33MnO2cathodematerialwassynthesizedbysolidstatereaction.Thematerialshowedasmallcoherentdomainsizeabout10nmdeterminedbyX-raydiffractionandtransmissionelectronmicroscopy.Theelectrochemicalpropertiesofthematerialwerestudiedindifferentpotentialwindowsof3.5―2.0Vand4.3―2.0V.Anirreversibletransformationtospinelphasewasobservedintheinitialseveralcycles,whichwasmoreprominentoncyclingat4.3―2.0V.ElectrochemicalimpedancespectroscopyshowedthattheLi+diffusioncoefficientofthematerialwasabout2×10–9cm2/s.Li0.33MnO2showedareversibledischargecapacityof140and200mA·h/ginthepotentialwindowsof3.5―2.0Vand4.3―2.0V,respectively.Butthecapacityretentionat4.3―2.0Vwaspoorduetothethickerspinellayerformedonthematerialsurface.