【摘要】 采用氢化燃烧法制备La2-xNixMg17(x=0.5,1,1.5)三元体系储氢材料,对其热力学、动力学进行研究发现:该体系材料具有很好的活性和较高的储氢量,其中La1.5Ni0.5Mg17在573K时吸放氢量分别为5.40和5.15mass%H。在553K下,体系α-β相区在600s之内吸放氢反应分数均大于91%,随着含Ni量的增加材料储氢容量降低,吸放氢速率增大。物相分析知道体系吸氢后的主相是MgH2,放氢后主相为Mg,同时存在Mg2Ni,LaNi5或LaH3等催化物质,从而使材料的氢化动力学性能得以明显改善。更多还原

【Abstract】 La_2-xNi_xMg₁₇（x=0.5, 1, 1.5） ternary alloys were prepared by hydriding combustion synthesis （HCS）. The thermodynamic and kinetic properties were investigated. These composites possess high activity and large capability of hydrogen storage. The maximum hydrogen absorption and desorption for La_1.5Ni_0.5Mg₁₇ are 5.40 and 5.15 mass% H at 573 K, respectively. In the 600 s the hydriding and dehydriding reacted fractions can reach more than 91% in the two-phase （α-β） region at 553 K. The more the Ni, the less the hydrogen storage capacities of the alloys are, the faster the reacted rates are. X-ray diffraction was used to characterize the crystal structure of the composite samples. It is found that the particles of mixed powders of MgH₂, Mg, Mg₂Ni, LaNi₅ and LaH₃ had catalytic action can improve the kinetic property of the materials greatly.更多还原