Hydriding/dehydriding behaviors of La2Mg17-10 wt.%Ni composite prepared by mechanical milling

作者：Liu Jing^*; Li Qian

来源：Journal of Rare Earths, 2013, 31(1): 73-78.

DOI：10.1016/S1002-0721(12)60238-5

• hydrogen storage
• La2Mg17-10 wt% Ni
• mechanical milling
• kinetics
• rare earths

The structure and hydriding/dehydriding behaviors of La2Mg17-10 wt.%Ni composite prepared by mechanical milling were investigated. Compared with the un-milled sample, the as-milled alloys were ready to be activated and the kinetics of hydrogen absorption was relatively fast even at environmental temperature. The composite milled for 10 h absorbed 3.16 wt.% hydrogen within 100 s at 290 K. The kinetic mechanisms of hydriding/dehydriding reactions were analyzed by using a new model. The results showed that hydrogenation processes for all composites were controlled by hydrogen diffusion and the minimum activation energy was 15.3 kJ/mol H-2 for the composite milled for 10 h. Mechanical milling changed the dehydriding reaction rate-controlling step from surface penetration to diffusion and reduced the activation energy from 204.6 to 87.4 kJ/mol H-2. The optimum milled duration was 5 h for desorption in our trials.

• 出版日期2013-1
• 单位贵州师范大学; 上海大学