高圧下における密度メタン-水素化合物の生成と安定性に関する研究
Using a combination of x-ray diffraction, optical spectroscopy, diamond anvil cell experiments, and density functional theory calculations, the dense CH₄-H₂ system was systematically investigated. At pressures as low as 4.8 GPa, two compounds—CH₄(H₂)₂ and (CH₄)₂H₂—were found to be stable, with the latter showing pronounced stiffening of the intramolecular vibrational mode associated with H₂ units. Upon further compression, a structurally distinct composition, (CH₄)₃(H₂)₂₅, was identified. This compound contains an exceptionally large proportion of molecular hydrogen, becoming the first reported material to exceed 50 wt% H₂. Stabilization of these phases is attributed to nuclear quantum effects, and they remain stable across a wide pressure range extending beyond 160 GPa.
Nuclear quantum effects stabilize the CH₄-H₂ compounds across a broad pressure range; within (CH₄)₂H₂, extreme hardening of the intramolecular vibrational mode of H₂ units was observed under compression.
The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).
See also:
https://h2-papers.org/en/papers/35687440