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Updated: May 13, 2026
A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
Published on: August 17, 2016
Effects of Al-based additives on the hydrogen storage performance of the Mg(NH2)2-2LiH system
Hujun Cao1, Yao Zhang, Jianhui Wang
1Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
Abstract:
The Mg(NH2)2-2LiH composite is a promising hydrogen storage material due to its relatively high reversible hydrogen capacity (~5.6 wt%) and suitable thermodynamic properties that allow hydrogen sorption conducting at temperatures below 90 °C. However, the presence of a severe kinetic barrier inhibits its low-temperature operation. In the present work, Li3AlH6 was introduced to the Mg(NH2)2-2LiH system. Experimental results show that a 3.2% mol Li3AlH6-modified Mg(NH2)2-2LiH sample released hydrogen at a rate ca. 4.5 times as fast as that of the Li3AlH6-free sample at 140 °C. The enhancement of desorption kinetics was simultaneously demonstrated by activation energy (Ea) of ca. 96.3 ± 9 kJ mol(-1) which was significantly decreased by 31 kJ mol(-1) from that of the Li3AlH6-free sample. The interaction of Li3AlH6 and Mg(NH2)2 during ball milling results in the formation of LiAl(NH)2, LiNH2 and Mg3N2. LiAl(NH)2 was actually the active species for the enhancement of dehydrogenation/re-hydrogenation kinetics of the system.
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