Structural Features and Phase Transitions during Dehydrogenation of a Composite Based on Magnesium Hydride and Metal-Organic Framework Structures MIL-101 (Cr).

Autor: Kudiiarov, V. N., Kurdyumov, N. E., Elman, R. R., Pushilina, N. S.
Zdroj: Journal of Surface Investigation: X-Ray, Synchrotron & Neutron Techniques; Oct2023, Vol. 17 Issue 5, p1156-1161, 6p
Abstrakt: It is shown that a composite based on magnesium hydride and metal-organic framework, formed during mechanical synthesis in a high-energy ball mill, has a core–shell structure in which magnesium hydride particles are coated with nanoscale particles of the MIL-101 metal-organic framework. The distribution of particles of the metal-organic framework creates trapping centers and channels for hydrogen diffusion, resulting in a decrease in the temperature of hydrogen desorption from magnesium hydride by 270°C compared to pure MgH2. In turn, lowering the temperature leads to a decrease in the desorption activation energy, which can favorably influence the use of such a composite as a hydrogen storage material. An in situ analysis of the phase transitions during dehydrogenation has shown that the phase transitions in the composite occur in three main stages. The first stage is characterized by defect annealing and structure relaxation without hydrogen desorption, the second stage involves hydrogen desorption without hydride dissociation, and the third stage involves hydride dissociation followed by residual hydrogen desorption. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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