学科分类
/ 4
71 个结果
  • 简介:InthispaperweusedMOF-5andCu3(BTC)2toseparateCO2/CH4andCH4/N2mixturesunderdynamicconditions.Bothmaterialsweresynthesizedandpelletized,thusallowingforameaningfulcharacterizationinviewofprocessscale-up.ThematerialswerecharacterizedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM).Byperformingbreakthroughexperiments,wefoundthatCu3(BTC)2separatedCO2/CH4slightlybetterthanMOF-5.BecausethecrystalstructureofCu3(BTC)2includesunsaturatedaccessiblemetalsitesformedviadehydration,itpredominantlyinteractedwithCO2moleculesandmoreeasilycapturedthem.Conversely,MOF-5withasuitableporesizeseparatedCH4/N2moreefficientlyinourbreakthroughtest.

  • 标签: BTC CO2 混合物 分离 扫描电子显微镜 X射线衍射
  • 简介:Amorphouscarbonandgrapheneco-modifiedLiFePO4nanocompositehasbeensynthesizedviaafacilepolyolprocessinconnectionwithafollowingthermaltreatment.Variouscharacterizationtechniques,includingXRD.Mossbauerspectra,Ramanspectra,SEM,TEM,BET,O2-TPO,galvanocharge-discharge,CVandEISwereappliedtoinvestigatethephasecomposition,carboncontent,morphologicalstructureandelectrochemicalperformanceofthesynthesizedsamples.TheeffectofintroducingwayofcarbonsourcesonthepropertiesandperformanceofLiFePO4/C/graphenecompositewaspaidspecialattention.Underoptimizedsyntheticconditions,highlycrystalizedolivine-typeLiFePO4wassuccessfullyobtainedwithelectronconductiveFe2PandFePasthemainimpurityphases.SEMandTEManalysesdemonstratedthegraphenesheetswererandomlydistributedinsidethesampletocreateanopenstructuredLiFePO4withrespecttographene,whiletheglucosederivedcarbonmainlycoatedoverLiFeP04particleswhicheffectivelyconnectedthegraphenesheetsandLiFePO4particlestoresultinamoreefficientchargetransferprocess.Asaresult,favorableelectrochemicalperformancewasachieved.Theperformanceoftheamorphouscarbon-grapheneco-modifiedLiFePO4wasfurtherprogressivelyimproveduponcyclinginthefirst200cyclestoreachareversiblespecificcapacityashighas97mAh·g-1at10Crate.

  • 标签: 无定形碳 复合材料 多元醇 锂离子电池 石墨 改性
  • 简介:Ba1.0Co0.7Fe0.2Nb0.1O3-δ(BCFN)oxidewithperovskitecubicstructurewassynthesizedbysolidstatereactionmethod.CO2corrosionofBCFNmembranewasinvestigatedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),diffusereflectanceinfraredFouriertransformedspectroscopy(DRIFT)andX-rayabsorptionfinestructurespectroscopy(XAFS).Cobalt(Co)K-edgeabsorptionspectraofBCFNannealedinCO2revealthattheoxidationstatesofCoinallthesampleswerelargerthan+3andtheydecreasedwiththeincreaseofcalcinationtime.At800℃,1%CO2introducedintoHecouldspeedupthereductionofCocationsincomparisonwithpureHe.Inaddition,sulfateionsinthebulkofBCFNmembranepreferredtomigratetothesurfaceunderCO2calcinationandformmonoclinicBa(CO3)0.9(SO4)0.1besidesorthorhombicwitherite.Moreover,SEMresultsindicatethatthenucleationandgrowthofcarbonatesgrainsstartedatthegrainboundaryofthemembrane.

  • 标签: 钙钛矿型氧化物 CO2 氧化态 组织演变 退火 X射线吸收精细结构
  • 简介:利用水热技术合成了一个以Keggin型多金属氧酸盐和柔性有机配体为建筑块的三维超分子化合物[H2bbi]3[α-PMo12O40]2(1)(bbi=1,4-双-(咪唑-1-基)丁烷),用X-射线单晶衍射、元素分析、红外光谱和X-射线粉末衍射对晶体结构进行了表征.X-射线单晶衍射显示,该晶体属于三斜晶系,P-1空间群,a=1.18360(9)nm,b=1.20932(10)nm,c=1.77728(15)nm,α=74.0890(10)°,β=70.9490(10)°,γ=71.8160(10)°,V=2.2421(3)nm3,Z=2,Dc=3.109g/cm3,F(000)=2300,μ=3.39mm-1,S=1.047,R1=0.0350,wR2=0.0776[I〉2σ(I)].

  • 标签: 多金属氧酸盐 超分子 水热合成 晶体结构 KEGGIN
  • 简介:Twocalix[4]arenederivativescontaining1,2,3-triazolemoietyweresynthesizedviaK2CO3-catalyzed1,3-dipolarcycloadditionreactionbetweencalix[4]arene-basedazideandactivemethylenecompoundsingoodyields.Thestructuresofthetwocompoundssynthesizedhereinwerefullyconfirmedby1HNMR,,13CNMR,andMS(ESI).Thethermalanalysisshowedthatthemasslossesofthesynthesizedcompounds4and5containing1,2,3-triazolegroupsaresimilartoeachother.

  • 标签: 偶极环加成反应 芳烃衍生物 反应合成 三唑基 活性亚甲基化合物 CO
  • 简介:采用对称性破损态方法结合密度泛函理论,选用反铁磁双核配合物[Cu2(MMBPT)2Cl4(H2O)2.5](MMBPT=3-甲基-4-对甲基苯基-5-(2-吡啶)-1,2,4-三唑)作为研究对象,通过与实验数据相比较,探讨了不同密度泛函方法与基组对计算铜配合物交换耦合常数的准确度.结果表明,4种混合密度泛函DFT(B3LYP,B3P86,B3PW91和PBE0)的计算结果都能和实验所观察到的值-31cm-1符号一致,但只有B3PW91方法得到的结果和实验结果吻合程度最好,同时采用方法B3PW91方法计算所得的交换耦合常数Jab对基组的依赖性较大.研究表明,2个Cu(Ⅱ)离子之间弱的反铁磁相互作用主要源于单占据分子轨道SOMOs小的能量劈裂.

  • 标签: 1 2 4-三氮唑 双核铜配合物 磁性 密度泛函理论 对称性破损态
  • 简介:标题化合物C22H29N3O3以简单易得的试剂为原料,在乙醇溶剂中,微波辐射下经两步多组分反应合成得到.其结构通过单晶X射线衍射法确定,晶体属三斜晶系,空间群P-1,相对分子质量Mr=383.48,晶胞参数a=1.14770(12)nm,b=2.0657(2)nm,c=1.00780(12)nm,V=2.1841(4)nm3,Z=4,晶胞密度Dc=1.166mg/m3,吸收系数μ=0.078mm-1,单胞中电子的数目F(000)=824.晶体结构用直接法解出,经全矩阵最小二乘法对原子参数进行修正,最终的偏离因子为R1=0.0709,wR2=0.1405.在晶体结构中新形成的噌啉环为近似于共平面结构,而其中的哒嗪环则为船式构象.

  • 标签: 噌啉-4-甲酰胺 高效 多组分反应 晶体结构