Liu Yana, Zhu Jinglian, Liu Zhibing, Zhu Yunfeng, Zhang Jiguang, Li Liquan
College of Materials Science and Engineering, Nanjing Tech University, Nanjing, China.
Jiangsu Collaborative Innovation Centre for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing, China.
Front Chem. 2020 Feb 19;7:949. doi: 10.3389/fchem.2019.00949. eCollection 2019.
In this work, Magnesium nanoparticles with Pd decoration, ranging from 40 to 70 nm, were successfully coprecipitated from tetrahydrofuran (THF) solution, assigned as the Mg-Pd nanocomposite. The Mg-Pd nanocomposite exhibits superior hydrogen storage properties. For the hydrogenated Mg-Pd nanocomposite at 150°C, the onset dehydrogenation temperature is significantly reduced to 216.8°C, with a lower apparent activation energy for dehydrogenation of 93.8 kJ/mol H. High-content γ-MgH formed during the hydrogenation process, along with PH, contributes to the enhancing of desorption kinetics. The Mg-Pd nanocomposite can take up 3.0 wt% hydrogen in 2 h at a temperature as low as 50°C. During lower hydrogenation temperatures, Pd can dissociate hydrogen and create a hydrogen diffusion pathway for the Mg nanoparticles, leading to the decrease of the hydrogenation apparent activation energy (44.3 kJ/mol H). In addition, the Mg-Pd alloy formed during the hydrogenation/dehydrogenation process can play an active role in the reversible metal hydride transformation, destabilizing the MgH.
在本工作中，成功地从四氢呋喃（THF）溶液中共沉淀出粒径范围为40至70nm的负载钯的镁纳米颗粒，命名为Mg-Pd纳米复合材料。Mg-Pd纳米复合材料表现出优异的储氢性能。对于在150°C氢化的Mg-Pd纳米复合材料，起始脱氢温度显著降低至216.8°C，脱氢的表观活化能较低，为93.8 kJ/mol H。氢化过程中形成的高含量γ-MgH以及PH有助于解吸动力学的增强。Mg-Pd纳米复合材料在低至50°C的温度下2小时内可吸收3.0 wt%的氢。在较低的氢化温度下，Pd可使氢解离并为镁纳米颗粒创造氢扩散途径，导致氢化表观活化能降低（44.3 kJ/mol H）。此外，氢化/脱氢过程中形成的Mg-Pd合金在可逆金属氢化物转变中可发挥积极作用，使MgH不稳定。
