Dansirima Palmarin, Thiangviriya Sophida, Plerdsranoy Praphatsorn, Chanlek Narong, Utke Rapee
School of Chemistry, Institute of Science, Suranaree University of Technology Nakhon Ratchasima 30000 Thailand
Synchrotron Light Research Institute (Public Organization) Nakhon Ratchasima 30000 Thailand.
RSC Adv. 2023 Jun 5;13(25):16926-16934. doi: 10.1039/d3ra01914d.
This work focuses on the effects of Ni precursors (metallic Ni or MgNiH) on the formation of Mg-Fe-Ni intermetallic hydrides as well as their de/rehydrogenation kinetics and reversibility. After ball milling and sintering, the formation of MgFeH and MgNiH are found in both samples, while MgH is observed only in the sample with metallic Ni. Both samples show comparable hydrogen capacities of 3.2-3.3 wt% H during the 1 dehydrogenation, but the sample with metallic Ni decomposes at a lower temperature (Δ = 12 °C) and shows faster kinetics. Although phase compositions after dehydrogenation of both samples are comparable, their rehydrogenation mechanisms are different. This affects the kinetic properties upon cycling and reversibility. Reversible capacities of the samples with metallic Ni and MgNiH during the 2 dehydrogenation are 3.2 and 2.8 wt% H, respectively, while those during the 3-7 cycles reduce to ∼2.8 and 2.6 wt% H, respectively. Chemical and microstructural characterizations are carried out to explain de/rehydrogenation pathways.
这项工作聚焦于镍前驱体（金属镍或MgNiH）对Mg-Fe-Ni金属间氢化物形成的影响，以及它们的脱氢/加氢动力学和可逆性。经过球磨和烧结后，在两个样品中均发现了MgFeH和MgNiH的形成，而仅在含有金属镍的样品中观察到了MgH。在第一次脱氢过程中，两个样品均显示出相当的储氢容量，为3.2-3.3 wt% H，但含有金属镍的样品在较低温度下（Δ = 12 °C）分解，且动力学更快。尽管两个样品脱氢后的相组成相当，但其加氢机制不同。这影响了循环过程中的动力学性能和可逆性。含有金属镍和MgNiH的样品在第二次脱氢过程中的可逆容量分别为3.2和2.8 wt% H，而在第3-7次循环中分别降至约2.8和2.6 wt% H。进行了化学和微观结构表征以解释脱氢/加氢途径。
