LaMg8.40Ni2.34合金的相结构和储氢性能.pdf

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1、物理化学学~(WuliHuaxueXuebao)FebruaryActa尸．一Chim．Sin．2011，27(2)，403—407403[Article]www．whxb．pku．edu．cnLaMg8mNi2合金的相结构和储氢性能李金华’刘宝忠1,3韩树民，扈琳朱惜林王明智’l燕山大学亚稳材料制备技术与科学国家重点实验室，河北秦皇岛066004；z燕山大学环境与化学工程学院，河北秦皇岛066004；河南理工大学材料科学与工程学院，河南焦作454000)摘要：利用真空感应熔炼和退火方法制备了LaMg。。Ni合金．采用X射线衍射(

2、XRD)分析、扫描电镜(SEM)和压力．组成．温度(PCT)测试仪测试了合金的相组成、微观形貌和储氢性能．LaMg“oNi一合金由LazMgmLaMg：Ni和MgNi组成，且在第一次吸放氢循环中就可以完全活化．在558K下的可逆储氢量为3．01％(质量分数)，合金的PCT曲线表现出双吸氢平台，分别对应着形成的MgH和Mg：NiH．但是放氢曲线却只有一个平台出现，这是由MgH和MgNiH之问的协同脱氢作用产生的．LaMgeoNiz合金在吸放氢时的活化能分别为(52．4+0．4)g~(59．2+0．1)kJ·mol～，均低于Mg。Ni

3、合金．与纯Mg和MgzNi合金相比，LaMgsoN合金具有良好的活化性能、较高的储氢性能和优良的动力学性能．关键词：储氢材料：La-Mg-Ni合金：压力一组成-温度曲线：多相结构中图分类号：0642PhaseStructureandHydrogenStoragePropertiesofLaMg8．,oNi2．34AlloyLIJin—Hua’LIUBao—Zhong’，。HANShu—Min’_，HULinZHUXi—LinWANGMing—Zhi’(StateKeyLaboratoryofMetastableMaterialsS

4、cienceandTechnology,YanshanUniversity,Qinhuangdao066004,HebeiProvince,R．China；CollegeofEnvironmentalandChemicalEngineering,YanshanUniversity,Qinhuangdao066004,HebeiProvince,R．China；SchoolofMaterialScienceandEngineering,HenanPolytechenicalUniversity,Jiaozuo454000,Henan

5、Province,R．China)Abstract：TheLaMg840Ni234aloywaspreparedbyvacuuminductionmeltingandsubsequentheatingtreatment．Thephasestructure，morphology，andhydrogenstoragepropertieswerestudiedbyX—raydifraction(XRD)，scanningelectronmicroscopy(SEM)，andpressure-composition-temperature

6、(PCT)measurements．TheLaMg84oNi234alloywascomposedofLa2Mgl~，LaMg2Ni，andMg2Niphases．Thealloycanbeactivatedinthefirsthydridjng，dehydridingprocess．Itsreversiblehydrogenstoragecapacitywas3．01％(massfraction)at558K．PCTcuwesshowedtwohydridingplateauscorrespondingtotheformatio

7、nofMgH2andMg2NiH4andonlyonedehydridingplateau，whichisduetothesynergeticefectofhydrogendesorptionbetweenMgH2andMg2NiH4．TheactivationenergyvaluesofLaMg84oNJ2“alloywere(52．4+0．4)and(59．2+0．1)kJ·mol～forthehydridinganddehydridingprocesses，respectively，andthesewerelowerthan

8、thatoftheMg2Nialloy．TheLaMg84。Ni234alloyexhibitedgoodactivationbehavior，hydrogenadsorptionanddesorptionreversibility，andkine