Mg_2Ni_(1-x)Co_x合金相的固溶烧结法制备及结构和储氢性能  

Phase Structures and Hydrogen Storage Properties of Mg_2Ni_(1-x)Co_x Alloys Prepared by Solid Solution Sintering

作　　者：马勇 李祥志[1] 李永涛[1] 柳东明[1] 张庆安[1] 斯庭智[1] MA Yong LI Xiangzhi LI Yongtao LIU Dongming ZHANG Qing＇an SI Tingzhi(School of Materials Science and Engineering, Anhui University of Technology, Ma＇ anshan 243002, Chin)

机构地区：[1]安徽工业大学材料科学与工程学院,马鞍山243002

出　　处：《高等学校化学学报》2016年第10期1776-1783,共8页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:U1503192)资助~~

摘　　要：采用固溶烧结法制备了Mg_2Ni_(1-x)Co_x(x=0.10,0.15,0.20)合金,利用X射线衍射仪和压力-组成-温度测试仪等研究了Co含量对合金相结构和储氢性能的影响.结果表明,合金由Mg_2Ni型Mg_2(Ni,Co)主相及少量Mg和Mg Ni3Co新相组成.Mg2(Ni,Co)具有良好的可逆储氢性能,吸氢形成Mg_2Ni_(0.9)Co_(0.1)H_4型四元氢化物,其具有与父系氢化物HT-Mg_2NiH_4相近的放氢焓变(ΔHd=63.9 k J/mol H2).Mg_2Ni_(1-x)Co_x(x=0.10,0.15,0.20)合金具有良好的放氢动力学性能,二维相界面迁移为放氢过程的控制步骤.随着Co含量的增加,合金的放氢活化能(Ea)降低,其中,Mg_2Ni_(0.8)Co_(0.2)的Ea降低到54.0 k J/mol.Mg2Ni1-xCox（ x =0. 10,0. 15,0. 20） alloys were prepared by a novel method combining solid solution with sintering process. The effect of Co content on the phase structures and hydrogen storage properties were investigated by XRD and pressure-composition-temperature analyser. It was found that the alloys consisted of a Mg2Ni-type major phase Mg2（ Ni,Co）,minor Mg and a new phase Mg Ni3 Co. The Mg2（ Ni,Co）compounds displayed a reversible hydrogen storage process. After hydrogenation, the quaternary Mg2Ni0. 9Co0. 1H4-type hydride was formed with an enthalpy change of the hydrogen desorption（ ΔHd= 63. 9kJ / mol H2） approximate to the parent hydride HT-Mg2NiH4. The Mg2Ni1-xCox（ x =0. 10,0. 15,0. 20） alloys showed a superior desorption kinetics and the desorption process was mainly controlled by two-dimensional phase-boundary migration. For the Mg2Ni1-xCox（ x = 0. 10,0. 15,0. 20） alloys,the activation energy of hydrogen desorption（ Ea） decreased with the increase of Co content. As a result,the Eavalue of the Mg2Ni0.8Co0.2 alloy was significantly lowered to 54. 0 kJ / mol.

关 键 词：MG2NI型合金 Co合金化 固溶烧结 Mg2Ni0.9Co0.1H4 储氢性能 

分 类 号：O614[理学—无机化学]