The structure and hydriding/dehydriding behaviors ofLa2Mgl7-10 wt.%Ni composite prepared by mechanical milling were investigated. Compared with the tin-milled sample, the as-milled alloys were ready to be activated an...The structure and hydriding/dehydriding behaviors ofLa2Mgl7-10 wt.%Ni composite prepared by mechanical milling were investigated. Compared with the tin-milled sample, the as-milled alloys were ready to be activated and the kinetics of hydrogen ab- sorption 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 ofhydriding/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 H2 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 H2. The optimum milled duration was 5 h for desorption in our trials.展开更多
基金Project supported by the Guizhou Nomarch Fund Project of Excellent Technology and Education Talents (201019)Specialties Projects funded for the Scientific Research Condition of Guizhou High-Level Talents (TZJF200927)
文摘The structure and hydriding/dehydriding behaviors ofLa2Mgl7-10 wt.%Ni composite prepared by mechanical milling were investigated. Compared with the tin-milled sample, the as-milled alloys were ready to be activated and the kinetics of hydrogen ab- sorption 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 ofhydriding/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 H2 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 H2. The optimum milled duration was 5 h for desorption in our trials.
