Yin Yi, Li Bo, Yuan Zeming, Qi Yan, Zhang Yanghuan
Department of Functional Material Research, Central Iron and Steel Research Institute Beijing 100081 China
Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology Baotou 014010 China.
RSC Adv. 2018 Oct 8;8(60):34525-34535. doi: 10.1039/c8ra06500d. eCollection 2018 Oct 4.
In this investigation, the as-milled MgZnNi-4C (C = TiF, NbF) composites were successfully produced ball milling. The different influences between the catalysts TiF and NbF on the hydrogen storage behavior and microstructure of the composites were investigated by XRD, SEM, TEM and hydrogen absorption/desorption tests. The as-milled MgZnNi-4C (C = TiF, NbF) alloys contain the major phase Mg, the secondary phase MgNi, a small amount of MgZn, TiF and NbF. After hydrogenation, MgH and MgNiH are formed, which convert back into Mg and MgNi after dehydrogenation indicating that MgZn and the catalysts TiF and NbF do not react with hydrogen. Compared with NbF catalyzed alloy, the TiF catalyzed alloy has a faster hydrogen absorption/desorption kinetics. On the basis of Arrhenius equation, the dehydrogenation activation energy values of the as-milled MgZnNi-4C (C = TiF, NbF) alloys are 75.514 and 82.367 kJ mol H, respectively, while the value of ball-milled MgZnNi alloy is 109.830 kJ mol H. As a result, both TiF and NbF can significantly ameliorate the hydrogen storage thermodynamics. TiF shows better catalytic influence on hydrogen storage property of MgZnNi than NbF.
在本研究中，通过球磨成功制备了研磨态的MgZnNi-4C（C = TiF、NbF）复合材料。利用X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）以及吸氢/脱氢测试，研究了催化剂TiF和NbF对复合材料储氢行为和微观结构的不同影响。研磨态的MgZnNi-4C（C = TiF、NbF）合金包含主要相Mg、次要相MgNi、少量的MgZn、TiF和NbF。氢化后，形成了MgH和MgNiH，脱氢后又转变回Mg和MgNi，这表明MgZn以及催化剂TiF和NbF不与氢发生反应。与NbF催化的合金相比，TiF催化的合金具有更快的吸氢/脱氢动力学。基于阿累尼乌斯方程，研磨态的MgZnNi-4C（C = TiF、NbF）合金的脱氢活化能值分别为75.514和82.367 kJ·mol⁻¹H，而球磨态的MgZnNi合金的值为109.830 kJ·mol⁻¹H。因此，TiF和NbF都能显著改善储氢热力学性能。TiF对MgZnNi储氢性能的催化影响比NbF更好。
