Effect of Ni on Mg based hydrogen storage alloy Mg_3Nd  

作　　者：TONG Yanqing OUYANG Liuzhang ZHU Min 

机构地区：[1]College of Mechanical Engineering, South China University of Technology, Guangzhou 510641, China College of Mechanical Engineering, South China University of Technology, Guangzhou 510641, China College of Mechanical Engineering, South China University of Technology, Guangzhou 510641, China

出　　处：《Rare Metals》2006年第z1期289-294,共6页稀有金属（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation (No.50401015, 50371027) ;Guangdong Provincial Natural Science Foundation (Team project).

摘　　要：Magnesium-neodymium based alloys were prepared by induction melting in an alumina crucible under protection of pure argon atmosphere. XRD patterns show that the as-melted Mg-Nd and Mg3NdNi0.1 diffraction peaks can be excellently indexed with D03 structure (BiF3 type, space group Fm3m). The lattice constant of Mg3Nd phase is 0.7390 nm, which is determined by XRD analysis using Cohen′s extrapolation method. The reversible hydrogen storage capacity reaches 1.95wt.% for Mg3Nd and 2.68wt.% for Mg3NdNi0.1. The desorption of hydrogen takes place at 291 ℃ for Mg3Nd and at 250 ℃ for Mg3NdNi0.1. The alloys could absorb hydrogen at room temperature with rapid hydriding and dehydriding kinetics after only one cycle. The enthalpy (ΔH) and entropy (ΔS) of Mg3Nd-H dehydriding reaction were -68.2 kJ·mol-1 H2 and -0.121 kJ·(K·mol)-1 H2 determined by using van′t Hoff plot according to the pressure-composition-isotherms (P-C-I) curve measured at different temperatures. Hydrogen absorption kinetic property of Mg3NdNi0.1 alloy was also measured at room temperature.Magnesium-neodymium based alloys were prepared by induction melting in an alumina crucible under protection of pure argon atmosphere. XRD patterns show that the as-melted Mg-Nd and Mg3NdNi0.1 diffraction peaks can be excellently indexed with D03 structure (BiF3 type, space group Fm3m). The lattice constant of Mg3Nd phase is 0.7390 nm, which is determined by XRD analysis using Cohen′s extrapolation method. The reversible hydrogen storage capacity reaches 1.95wt.% for Mg3Nd and 2.68wt.% for Mg3NdNi0.1. The desorption of hydrogen takes place at 291 ℃ for Mg3Nd and at 250 ℃ for Mg3NdNi0.1. The alloys could absorb hydrogen at room temperature with rapid hydriding and dehydriding kinetics after only one cycle. The enthalpy (ΔH) and entropy (ΔS) of Mg3Nd-H dehydriding reaction were -68.2 kJ·mol-1 H2 and -0.121 kJ·(K·mol)-1 H2 determined by using van′t Hoff plot according to the pressure-composition-isotherms (P-C-I) curve measured at different temperatures. Hydrogen absorption kinetic property of Mg3NdNi0.1 alloy was also measured at room temperature.

关 键 词：MAGNESIUM hydrogen storage rare earth induction melting 

分 类 号：TG146.4[一般工业技术—材料科学与工程]