Optimization of AB2 type alloy composition with superior hydrogen storage properties for stationary applications
Optimization of AB2 type alloy composition with superior hydrogen storage properties for stationary applications
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DOI：
10.1016/j.ijhydene.2015.09.157
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发表时间：
2015-12
影响因子：
7.2
通讯作者：
K. Manickam;D. Grant;G. Walker
中科院分区：
文献类型：
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作者：
K. Manickam;D. Grant;G. Walker
通过在A位引入非化学计量比，改善了Laves相AB2型合金在常温(30-35℃)和中压(1-15bar)固定储氢应用中的储氢性能。在Ar气氛下，采用悬浮感应熔炼法制备了(Ti0.65Zr0.35)1+xMnCr0.8Fe0.2(x=0，0.05，0.075和0.1)C14Laves相AB2型合金。X-射线衍射分析表明，合成的样品为C14Laves相六方结构，空间群为P63/MMC。由压力-成分-等温线测量发现，(Ti0.65Zr0.35)1.1MnCr0.8Fe0.2的最大储氢量在35℃和32℃时约为2.2wt%，比商用水合合金C5的储氢量高约16%。(Ti0.65Zr0.35)1.05MnCr0.8Fe0.2合金的氢化ΔH为−26±2kJ/molH，ΔS为−98±6.5J/K/molH2。这些合金的加氢动力学相对较快，在10分钟内达到满负荷，而不需要任何活化。用速率方程分析了(Ti0.65Zr0.35)1.05MnCr0.8Fe0.2在不同温度下的加氢反应动力学数据，得到α+β相和β相的氢化反应活化能分别为19℃和29℃。从高压DSC数据得到的伪van‘t Hoff图给出的热力学结果与由PCI测得的热力学结果相当，证明是确定这一热力学数据的一种比较筛选方法。
Improved hydrogen storage properties for an ambient temperature (30–35 °C) and moderate pressure (1–15 bar) stationary hydrogen storage application have been achieved for Laves phase AB2type alloys by introducing non-stoichiometry at the A site. A range of (Ti0.65Zr0.35)1+xMnCr0.8Fe0.2(x = 0, 0.05, 0.075 and 0.1) C14 Laves phase AB2type alloys have been synthesized by levitation induction melting under an argon atmosphere. X-ray diffraction revealed formation of a single phase with a C14 Laves phase hexagonal structure with the space group of P63/mmc. From Pressure-Composition-Isotherm measurements, the maximum hydrogen storage capacity was found to be around 2.2 wt% at 35 bar and 32 °C for (Ti0.65Zr0.35)1.1MnCr0.8Fe0.2, which is approximately 16% higher than that of the commercially available Hydralloy C5. The (Ti0.65Zr0.35)1.05MnCr0.8Fe0.2alloy has a hydrogenation ΔH of −26 ± 2 kJ/mol H2and ΔS of −98 ± 5 J/K/mol H2. The hydrogenation kinetics of these alloys are relatively fast reaching full capacity within 10 min without any requirement for activation. The hydrogenation kinetics data for (Ti0.65Zr0.35)1.05MnCr0.8Fe0.2at different temperatures were analysed using rate equations and the activation energy was found to be 19 ± 1 kJ/mol in the α + β phase and 29 ± 2 kJ/mol in the β phase. Pseudo van't Hoff plot from high pressure DSC data gave thermodynamic results comparable with that measured from the PCI, proving as a comparative screening method to determine this thermodynamic data.