Preparation and hydrogen storage properties of Mg2Ni intermetallic nanoparticles
Preparation and hydrogen storage properties of Mg2Ni intermetallic nanoparticles
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DOI：
10.1088/0957-4484/15/3/006
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发表时间：
2004-03
期刊：
影响因子：
3.5
通讯作者：
H. Shao;Hairuo Xu;Yuntao Wang;Xingguo Li
中科院分区：
文献类型：
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作者：
H. Shao;Hairuo Xu;Yuntao Wang;Xingguo Li
在这项工作中，我们研究了由镁和镍纳米颗粒制备的化学计量比镁镍金属间化合物纳米颗粒的储氢性能。镁镍颗粒的平均尺寸约为30-50 nm，晶格常数为a=5.22A，c=13.29A。未活化的镁镍化合物表现出良好的储氢性能。在523K、573K和623K时，吸氢量分别为2.77、2.93和3.03wt%。经过一次简单的活化处理，得到的镁镍在293、348、426和493K时的吸氢量分别为1.74、2.07、2.31和2.82wt%。在523K、573K和623K时，吸附和脱附平台氢压分别为2.5bar和0.8bar、5.9bar和3.4bar，623K分别为12.7bar和9.7bar，得到的van‘t Hoff方程为−(P/bar)=Δ3464/T+6.541，生成焓(ΔH)和熵(−S)分别为−66.32kJ/molH2和Δ125.3 J K−1/molH2。
In this work we investigated the hydrogen storage properties of stoichiometric Mg2Ni intermetallic nanoparticles produced from Mg and Ni nanoparticles. The mean size of the Mg2Ni particles is about 30–50 nm and the lattice constants of the Mg2Ni compound are a = 5.22 A, c = 13.29 A. The Mg2Ni compound showed excellent hydrogen storage properties without activation. It can absorb 2.77, 2.93 and 3.03 wt% hydrogen at 523, 573 and 623 K respectively. After one simple activation process, the obtained Mg2Ni absorbed 1.74, 2.07, 2.31 and 2.82 wt% hydrogen at 293, 348, 426 and 493 K respectively. The absorption and desorption plateau hydrogen pressures are about 2.5 and 0.8 bar at 523 K, 5.9 and 3.4 bar at 573 K and 12.7 and 9.7 bar at 623 K. The resulting van't Hoff equation is log(P/bar) = −3464/T+6.541 and the formation enthalpy (ΔH) and entropy (ΔS) for the Mg2NiH4 are −66.32 kJ/mol H2 and −125.3 J K−1/mol H2.