Preparation and Properties of Ball-Milled MgH₂/Al Nanocomposites for Hydrogen Storage

Abstract

For reversible hydrogen storage properties of 17MgH 2 + 12Al § Mg 17 Al 12 + 17H 2 , MgH 2 /Al nanocomposites (I)(IV) synthesized by ball milling of MgH 2 and Al (or AlH 3 ) were studied in connection with milling conditions. The milling processes consisting of two steps were effective to improve the hydrogen storage behavior; MgH 2 was first milled with solutions of triethylaluminium (TEA) in hexane, followed by addition of Al and TEA solutions. The mixtures were further milled to yield the nanocomposite (III). In preparing the nanocomposite (IV), AlH 3 was used instead of Al. For the nanocomposites (III) and (IV), it was proved by XRD, TDS, DSC and PCI that such ball-milling led to high dispersion of nanocrystalline MgH 2 in Al and/or AlH 3 matrix in the resulting nanocomposites. In DSC measured under a 0.1 MPa hydrogen atmosphere, the nanocomposites (III) and (IV) exhibited reversible H 2 absorption and desorption at 493503 and 573593 K, respectively.

Picturing the Gap Between the Performance and US‐DOE's Hydrogen Storage Target: A Data‐Driven Model for MgH2 Dehydrogenation

“…The above results clearly show that the developed model not only closely matches the theoretical calculations but also aligns with the experimental conclusions from metal‐doped MgH 2 materials. The energy barriers predicted by the descriptors show a high consistency with the onset dehydrogenation temperatures observed in some typical experiments reported to date (Figure 6d and Table S13) [39–44] . Modifying the surface of MgH 2 can reduce the energy barrier for dehydrogenation, resulting in accelerated formation and growth of Mg nuclei on the surface for more efficient dehydrogenation and lower reaction temperature [45,46] .…”

Picturing the Gap Between the Performance and US‐DOE's Hydrogen Storage Target: A Data‐Driven Model for MgH2 Dehydrogenation

“…The above results clearly show that the developed model not only closely matches the theoretical calculations but also aligns with the experimental conclusions from metal‐doped MgH 2 materials. The energy barriers predicted by the descriptors show a high consistency with the onset dehydrogenation temperatures observed in some typical experiments reported to date (Figure 6d and Table S13) [39–44] . Modifying the surface of MgH 2 can reduce the energy barrier for dehydrogenation, resulting in accelerated formation and growth of Mg nuclei on the surface for more efficient dehydrogenation and lower reaction temperature [45,46] .…”

“…The energy barriers predicted by the descriptors show a high consistency with the onset dehydrogenation temperatures observed in some typical experiments reported to date (Figure 6d and Table S13). [39][40][41][42][43][44] Modifying the surface of MgH 2 can reduce the energy barrier for dehydrogenation, resulting in accelerated formation and growth of Mg nuclei on the surface for more efficient dehydrogenation and lower reaction temperature. [45,46] Combining Eqs.…”

A Comprehensive Review on Hydrogen Absorption Behaviour of Metal Alloys Prepared through Mechanical Alloying

“…Furthermore, the hydriding kinetics of MgH2 hydride is relatively slow because the dissociation of molecular hydrogen into hydrogen atoms is difficult on the surface of Mg metal [43]. Several reports are found in the literature concerning synthesis and hydrogen properties of Mg-based alloys synthesized by mechanical alloying [3,[44][45][46]. Another interesting study is (a-c) were reprinted with permission from [36], with permission from Elsevier, 2016 (d) reproduced from [37], with permission from Elsevier, 2015; (e) reproduced from [38], with permission from Elsevier, 2000 and (f) reproduced from [39], with permission from Elsevier, 1999.…”

“…Furthermore, the hydriding kinetics of MgH 2 hydride is relatively slow because the dissociation of molecular hydrogen into hydrogen atoms is difficult on the surface of Mg metal [43]. Several reports are found in the literature concerning synthesis and hydrogen properties of Mg-based alloys synthesized by mechanical alloying [3,[44][45][46]. Another interesting study is Andreasen [31].…”