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摘要:
MgH2 as one of potential solid-state hydrogen storage materials has been widely investigated during past decades due to its large capacity and abundant elemental reserves. Nonetheless, the presented ultra-high thermal stability and sluggish kinetics hinder a further application. In the present work, the Ni and Pt nano-clusters evolved from Ni@Pt core-shell nanoparticles facilitated the de/re-hydrogenation process of MgH2. The onset dehydrogenation temperature of MgH2-10 wt% Ni@Pt was greatly lowered by maximum 108 K compared with 601 K of the pristine MgH2, and the dehydrogenation process can be terminated below 573 K. The thermal stability of the MgH2-based system was remarkably tailored to 69.4 kJ (mol H-2)(-1) from 76.2 kJ (mol H-2)(-1) of the pristine MgH2. Meanwhile, the hydrogen storage kinetics of MgH2-10 wt% Ni@Pt was greatly improved compared with the pristine MgH2. Density functional theory calculations confirmed that Pt nano-clusters serving as a destabilizer and catalyst not only greatly destabilize the thermal stability of MgH2 but also catalyze its reactions, in particular with the Pt(2 2 0) slab. The effective catalyst-reactant interfaces coupling with regulated surface determined desorption/absorption were deeply investigated and built, leading to an excellent agreement with experiments. The involving of transition metal clusters lays foundation of a new way of improving the hydrogen storage properties and paves a way of developing next-generation hydrogen storage materials.
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来源 :
CHEMICAL ENGINEERING JOURNAL
ISSN: 1385-8947
年份: 2022
卷: 435
1 5 . 1
JCR@2022
1 5 . 1 0 0
JCR@2022
ESI学科: ENGINEERING;
ESI高被引阀值:49
JCR分区:1
中科院分区:1
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