A two-dimensional hydrogen boride-containing sheet of the present invention has a two-dimensional network that consists of (HB).sub.n (n4).

A two-dimensional hydrogen boride-containing sheet of the present invention has a two-dimensional network that consists of (HB).sub.n (n4).

Thermal energy storage (TES) systems based on metal hydride pairs using new class of high efficiency materials are evaluated. The use of low temperature metal cost effective material such hydrides NaAlH4 and Na3AlH6 became possible. In order to obtain high efficiency at reasonable cost high temperature materials were altered by the addition of materials to form reversible alloys and hydrides. The compounds were cycled to determine stability of hydrogen capacity over extended number of cycling. A thermal energy storage system based on two metal hydride pairs such as CaAl/CaH2/Al:NaAlH.sub.4, Ca.sub.2Si/CaH.sub.2/Si:Na.sub.3AlH.sub.6 and NaMgH.sub.2FSi/Mg2SiNaF:Na.sub.3AlH.sub.6 allows low cost and high efficiency performance.

The present disclosure is directed to a system and a method for hydride generation. In some embodiments, the system includes an assembly for introducing hydride generation reagents into a mixing path or mixing container, where the assembly includes first chamber configured to contain a first hydride generation reagent and a second chamber configured to contain a second hydride generation reagent. A first plunger is configured to translate within the first chamber and cause a displacement of the first hydride generation reagent, and a second plunger is configured to translate within the second chamber and cause a displacement of the second hydride generation reagent. The assembly further includes base coupling the first plunger and the second plunger together.

Rare earth (RE) superhydrides exhibit high temperature superconductivity but are difficult to characterize and use in applications due to their high formation and stability pressures, which are typically in excess of 100 GPa. Cryomilling of metal precursors improves hydrogen reactivity and hydrogen uptake for forming such metal hydrides at lower pressures. As an example, an elemental lanthanum precursor was milled at liquid nitrogen temperatures for different time intervals. After exposure to gaseous hydrogen at 380? C. and 100 bar, a systematic enhancement of hydrogen absorption with increasing ball milling time was found for forming the LaH.sub.x, x=2-3 phase. Exposing the La precursor to pressures up to 60 GPa with an ammonia borane (BNH.sub.6) hydrogen source resulted in a hypervalent LaH.sub.4 phase. This LaH.sub.4 phase is associated with the suppression of a rhombohedral distortion of the Fm3m cubic structure after cryomilling the precursor.

To provide a metal-based structure or nanoparticles whose homogeneity is not deteriorated and whose sticking formation is easy, and a production method thereof with a high safety. A metal-based structure comprises a hydrogen compound, cluster, or an aggregate thereof, represented by the general formula: M.sub.mH. The M is a metal-based atom. The m is an integer of 3 or more and 300 or less. H is a hydrogen atom.

To provide a metal-based structure or nanoparticles whose homogeneity is not deteriorated and whose sticking formation is easy, and a production method thereof with a high safety. A metal-based structure comprises a hydrogen compound, cluster, or an aggregate thereof, represented by the general formula: M.sub.mH. The M is a metal-based atom. The m is an integer of 3 or more and 300 or less. H is a hydrogen atom.

To provide a metal-based structure or nanoparticles whose homogeneity is not deteriorated and whose sticking formation is easy, and a production method thereof with a high safety. A metal-based structure comprises a hydrogen compound, cluster, or an aggregate thereof, represented by the general formula: M.sub.mH. The M is a metal-based atom. The m is an integer of 3 or more and 300 or less. H is a hydrogen atom.

To provide a metal-based structure or nanoparticles whose homogeneity is not deteriorated and whose sticking formation is easy, and a production method thereof with a high safety. A metal-based structure comprises a hydrogen compound, cluster, or an aggregate thereof, represented by the general formula: M.sub.mH. The M is a metal-based atom. The m is an integer of 3 or more and 300 or less. H is a hydrogen atom.

Provided are a hydrogen boride-containing composition, a hydrogen generation system, and a fuel cell system that achieve further performance improvement of a hydrogen supply source with a hydrogen boride-containing sheet. The hydrogen boride-containing composition contains a hydrogen boride-containing sheet having a two-dimensional network consisting of (BH).sub.n(n?4, where n is an integer) and an electron donor. At least a portion of the electron donor is supported on the hydrogen boride-containing sheet, electrons of the electron donor are supplied to the hydrogen boride-containing sheet by external stimulus, and hydrogen is generated from the hydrogen boride-containing sheet into which the electrons are injected.