分子模拟方法预测MOFS材料储氢能力

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1、上海交通大学硕士学位论文分子模拟方法预测MOFs材料储氢能力姓名：付嘉申请学位级别：硕士专业：物理化学指导教师：孙淮20090101摘要件下的相对储氢性能。论文中报道了应用同一力场预测一系列不同MOFs材料的储放氢性能的结果以及关于材料结构和储氢能力的探讨。研究发现，对于具有相似化学结构的MOFs材料，影响材料储放氢能力的关键因素是材料的自由体积。关键词：储氢，MOF，第一原理，力场第II页ABSTRACTABSTRACTGreatattentionwaspaidtodesignandsynthesizenewMOFsforhydrogenstorage.Us

2、ingmolecularsimulationmethodtopredictthecapabilitiesofhydrogenstorageofdifferentmaterialsundervariousconditionscanprovidetheoreticalguidancetoexperimentalresearchandtoreducethetimeandmoneycosts.Underlyingforcefieldisthecenterissueofmolecularsimulation,butexistingparametersforhydroge

3、nadsorptioninMOFswerederivedbyfittinglimitedexperimentaldataortakenfromgenericforcefields,botharelimitedinaccuracyandreliability.Inthiswork,westartedfromquantumchemistrycalculationsonmodelcompoundsofMOF-5tostudytheinteractionsbetweenH2andMOF-5.Themodelcompoundswereorganiclinkerandme

4、taloxidecluster.ThecalculationswereperformedattheMP2levelofmethod.Basedonthequantumchemistrydata,wederivedclassicalforcefieldparameterswhichincludedchargeandvanderWaalsparameters.TheFeynman-Hibbseffectivepotentialwasusedtoconsiderthequantumeffectatlowtemperature.Conventionalgrandcan

5、onicalMonteCarlo(GCMC)simulationswerecarriedouttopredictthehydrogenadsorptionisothermsofMOF-5withthenewlydevelopedforcefield.Thesimulationresultsagreewellwithexperimentresultsinabroadrangeoftemperaturesandpressures,whichdemonstratedthereliabilityoftheforcefieldandsimulationmethod.Si

6、ncetheforcefieldparameterswerebasedonquantumchemistrycalculationsindependentlyfromanyexperimentaldata,thisapproachcanbeusedtopredicttherelativecapabilitiesofhydrogenstorageforvariousMOFsreliably.Inthiswork,wereportedthepredictedhydrogenadsorption/releasecapabilitiesbetween0.1and8MPa

7、atvarioustemperaturesforaseriesofMOFsmaterials.Therelationshipbetweenthestructureandstoragecapacitywasanalyzed.Wefoundthatthefractionoffreevolumeisthekeyfactorthatinfluencesthehydrogenstoragecapabilityforgivenchemicalconstitutions.Keywords:HydrogenStorage,weakinteraction,MOF,Molecul

8、arSimulation第III页上海