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1、物理化學(xué)學(xué)報(bào)(WuliHuaxueXuebaoAugustActaP.一Chim.Sin.2012,28(8),1877—18841877[Article】doi:10.3866/PKU.WHXB201205281、^^,、^,.whxb.pku.edu.cnAI摻雜對(duì)Mg2Ni合金的電子結(jié)構(gòu)及貯氫性能的影響藍(lán)志強(qiáng)肖瀟蘇鑫陳捷獅郭進(jìn)(廣西大學(xué)物理科學(xué)與工程技術(shù)學(xué)院,有色金屬及材料加工新技術(shù)教育部重點(diǎn)實(shí)驗(yàn)室,南寧530004)摘要:采用基于密度泛函理論(DFT)的平面波贗勢(shì)(PW-PP)方法,計(jì)算Mg一xAINiH(x=O,0.125,0.25)合金的晶胞體積、電子態(tài)密度
2、、鍵序、電荷布居、生成焓,分析原子問成鍵和結(jié)構(gòu)的穩(wěn)定性,研究Al部分替代Mg對(duì)Mg~Ni合金及其氫化物的結(jié)構(gòu)和儲(chǔ)氫性能的影響.結(jié)果表明:隨著AI含量的增加,MgNi合金晶胞體積減小,不利于氫原子進(jìn)入合金中,導(dǎo)致合金的儲(chǔ)氫容量降低.在Mg一NiH(x=0,O.125,0.25)中,Mg—H和AI—H相互作用遠(yuǎn)小于Ni-H的相互作用,隨著Al含量的增加,氫化物生成焓減少以及Ni—H的相互作用減弱,氫化物的結(jié)構(gòu)穩(wěn)定性降低,Al部分替代Mg能有效改善MgNi合金釋氫動(dòng)力學(xué)性能.關(guān)鍵詞:第一性原理:MgzNi合金;貯氫性能:電子結(jié)構(gòu):態(tài)密度中圖分類號(hào):O641EffectofDo
3、pingwithAluminiumontheElectronicStructureandHydrogenStoragePropertiesofMg2NiAlloyLANZhi-QiangXIAOXiaoSUXinCHENJie—ShiGUOJin(KeyLaboratoryofNewProcessingTechnologyforNonferrousMetalsandMaterials.MinistryofEducationCollegeofPhysicalScienceandTechnology,GuangxiUniversity,Nanning530004,PR.Ch
4、ina)Abstract:UsingplanewavepseudOpOtentialmethodsbasedondensityfunctionaItheory,theunitcellvolumes,theelectronicdensitiesofstates,thebondOrders,thechargepopulations,andtheformationenthalpiesofMg2-xAlNiH,(x=0,0.125,0.25)alloyswerecalculated.Byanalyzingatombondingandstructuralstability,the
5、effectsofpartiallysubstitutingAIforMgonthestructureandhydrogenstoragepropertyofthealloysandtheirhydrideswereinvestigated.1twasshownthattheunitcellvolumeoftheMg2NialloydecreaseswiththeincreaseofAIcontent:thedecreasedunitcelIvolumehinderstheincorporationofhydrogenatoms,thusreducingthehydro
6、genstoragecapacity.ForMg2一xANiH4(x=0,0.125,0.25)hydrides,theMg—HandAI-HinteractionsaremuchweakerthantheNi-Hinteraction.However,theNi-HinteractioniSweakenedandthehydrideenthalpyofformationdecreaseswithjncreasedAJcontent.AIthoughthestabilityofthehydridestructurejSweakened.hydrogendesorptio
7、nkinetics-fortheMg2NihydridecanbeimprovedwiththepartiaIsubstitutionofAIforMg.KeyWords:First_principIes:Mg2NiAlloy;Hydrogen—storageproperty;ElectronicstructureDensityofstate1引言石化能源的日益枯竭以及對(duì)環(huán)境的污染使得對(duì)氫氫能作為一種清潔能源受到人們的廣泛關(guān)注,能的研究和開發(fā)日趨重要.氫氣的儲(chǔ)存和運(yùn)輸是氫Received:January28,2012:Revised:Ma