Effect of lanthanum hydride on microstructures and hydrogen storage performances of 2LiNH_2-MgH_2 system  

作　　者：朱惜林 韩树民 赵鑫 李媛 刘宝忠 

机构地区：[1]College of Environmental and Chemical Engineering,Yanshan University [2]State Key Laboratory of Metastable Materials Science and Technology,Yanshan University [3]School of Materials Science and Engineering,Henan Polytechnic University

出　　处：《Journal of Rare Earths》2014年第5期429-433,共5页稀土学报（英文版）

基　　金：Project supported by National Natural Science Foundation of China(51001043,50971112);Program for New Century Excellent Talents in University(NCET-11-0943);China Postdoctoral Science Special Foundation(201104390);Foundation for University Key Teacher in the University of Henan Province(2011GGJS-052);Program for Innovative Research Team(in Science and Technology)in the University of Henan Province(2012IRTSTHN007)

摘　　要：Hydrogen storage properties of 2LiNH2-MgH2 system were improved by adding lanthanum hydride （LaH3）, and the role of LaH3 in hydrogen sorption process of Li-Mg-N-H system was investigated. Temperature programmed sorption results showed that the addition of lanthanum hydride reduced the dehydriding/hydriding onset temperature of 2LiNH2-MgH2 system by at least 15 K. Moreover, A 0.053 wt.%/min average rate was determined for the hydrogen desorption of 2LiNH2-MgH2-0.05LaH3 composite, while it was only 0.035 wt.%/min for 2LiNH2-MgH2 system. Hydrogen absorption capacity increased from 1.62 wt.% to 2.12 wt.% within 200 min by adding LaH3 into 2LiNH2-MgH2 system at 383 K. In the dehydrogenation of 2LiNH2-MgH2-0.05LaH3 composite, LaH2 transferred to LaN phase, which reversed to LaH2 in the following hydrogen adsorption process. The reversible reaction of LaH2 ef- fectively promoted the hydrogen sorption of Li-Mg-N-H system. Moreover, the homogenous distribution of fine La hydride was fa- vorable to improving effect of lanthanum hydride.Hydrogen storage properties of 2LiNH2-MgH2 system were improved by adding lanthanum hydride （LaH3）, and the role of LaH3 in hydrogen sorption process of Li-Mg-N-H system was investigated. Temperature programmed sorption results showed that the addition of lanthanum hydride reduced the dehydriding/hydriding onset temperature of 2LiNH2-MgH2 system by at least 15 K. Moreover, A 0.053 wt.%/min average rate was determined for the hydrogen desorption of 2LiNH2-MgH2-0.05LaH3 composite, while it was only 0.035 wt.%/min for 2LiNH2-MgH2 system. Hydrogen absorption capacity increased from 1.62 wt.% to 2.12 wt.% within 200 min by adding LaH3 into 2LiNH2-MgH2 system at 383 K. In the dehydrogenation of 2LiNH2-MgH2-0.05LaH3 composite, LaH2 transferred to LaN phase, which reversed to LaH2 in the following hydrogen adsorption process. The reversible reaction of LaH2 ef- fectively promoted the hydrogen sorption of Li-Mg-N-H system. Moreover, the homogenous distribution of fine La hydride was fa- vorable to improving effect of lanthanum hydride.

关 键 词：hydrogen storage performances Li-Mg-N-H system lanthanum hydride kinetics rare earths 

分 类 号：TB34[一般工业技术—材料科学与工程]