Magnesium Nanoparticles With Pd Decoration for Hydrogen Storage
Yana Liu, Jinglian Zhu, Zhibing Liu, Yunfeng Zhu, Jiguang Zhang, Liquan Li
Abstract
In this work, Magnesium nanoparticles with Pd decoration, ranging from 40 to 70 nm, were successfully coprecipitated from THF solution, assined as the Mg-Pd nanocomposite. The Mg-Pd nanocomposite exhibits superior hydrogen storage properties. For the hydrogenated Mg-Pd nanocpmposite at 150 oC, the onset dehydrogenation temperature is significantly reduced to 216.8 oC, with a lower apparent activation energy for dehydrogenation of 93.8 kJ/mol H2. High content γ-MgH2 formed during the hydrogenation process, along with PH0.706 contributes to the enhancing of desorption kinetics. The Mg-Pd nanocomposite can take up 3.0 wt% hydrogen in 2 h at temperater low as 50 oC. During lower hydrogenation tempeatures, Pd can dissociate hydrogen and create a hydrogen diffusion pathway for the Mg nanopaticles, leading to the decrease of the hydrogenation apparent activation energie (44.3 kJ/mol H2). In addition, the Mg-Pd alloy formed during hydrogenation/dehydrogenation process can play an active role in the reversible metal hydride transformation, destabilizing the MgH2.