Hydrogen storage properties and thermal stability of amorphous Mg-70(RE25Ni75)(30) alloys

作者：Chen, He-xin; Wang, Zhong-min^*; Zhou, Huai-ying; Ni, Chen-yuan; Deng, Jian-qiu; Yao, Qing-rong

来源：Journal of Alloys and Compounds, 2013, 563: 1-5.

DOI：10.1016/j.jallcom.2013.01.159

• Mg alloy
• Amorphous alloys
• Hydrogen storage properties
• Thermal stability

In this study, amorphous Mg-70(RE25Ni75)(30) (RE = La, Pr, Nd) alloys were produced by melt spinning, their hydrogen storage properties and the thermal stabilities have been studied by means of PCTPro2000 and Differential Scanning Calorimetry (DSC), respectively. After hydrogenation of Mg-70(RE25Ni75)(30) samples at 573 K under 2 MPa hydrogen pressure, XRD results indicate the formation of new phases of MgH2, Mg2NiH4, LaH3.01 (RE = La), PrH2.92 (RE = Pr) and Nd2H5 (RE = Nd). The experimental data of hydrogen desorption kinetics at 523 K, 553 K, 573 K are well fitted through Avrami-Erofeev equation, and the hydrogen desorption kinetics were in the order of Pr > La > Nd. Based on the results of DSC analysis, dehydrogenation activation energies of these samples were determined to be 68.81 +/- 2.50 kJ/mol (RE = La), 64.79 +/- 1.09 kJ/mol (RE = Pr) and 73.37 +/- 3.23 kJ/mol (RE = Nd), which are in accordance with the results of hydrogen desorption kinetics. As shown in the P-C isotherm curves, two hydrogen absorption plateaus at about 0.07 MPa and 0.2 MPa have been observed for Mg-70(RE25Ni75)(30) (RE = La, Pr) tested at 573 K, while there is only one sloping hydrogen absorption plateau in the range of 0.06-0.3 MPa for Mg-70(Nd25Ni75)(30) alloy. The maximum hydrogen absorption capacity is 4.21 wt.% for Mg-70(Nd25Ni75)(30) and the maximum hydrogen desorption capacity is 2.74 wt.% for Mg-70(Pr25Ni75)(30).

• 出版日期2013-6-25
• 单位桂林电子科技大学