Mechanism of Solid Ammonia Stabilization at Ambient Temperature: Insights from Thermodynamics, Phonon Calculation, and Micromechanics.

ABSTRACT: The stabilization of low-temperature solid-state ammonia at ambient temperature was recently achieved by confining fine crystals within a boric acid glass matrix through freeze-drying using liquid nitrogen, opening a new frontier for hydrogen storage materials. We determined the stabilization mechanism using a thermodynamic model supported by first-principles phonon calculation and pressure analysis based on micromechanics. Phonon calculation revealed vibrational densities of states (DOS) for the intermolecular translational and rotational modes of NH₃ molecules, as well as intramolecular librational and bending modes of hydrogen atoms. Simulations incorporating the computed DOS into a thermodynamic model reveal that sub-GPa pressure is exerted on ammonia crystals by the surroun

SUBMITTER: Morishita M 

PROVIDER: S-EPMC12703987 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature