Fully Reversible High-Capacity Ammonia Storage in a Series of Phase-Transformable Molecular Nickel Thiocarboxylates
- 1Department of Chemistry
- 2Kyushu University
Abstract
Ammonia (NH 3 ) is an indispensable chemical commodity in modern society, but its nature as a toxic and corrosive gas makes its storage and transport difficult. Here, we report non-porous molecular nickel thiobenzoate [Ni 2 (PhCOS) 4 ] and derivatives, as a distinct class of phase-transformable adsorbents for reversible and high-density ammonia storage in ambient conditions. Despite lacking intrinsic porosity, [Ni 2 (PhCOS) 4 ] presented excellent sorption capacity of 23.5 mmol/g (effective reversible capacity: 22.0 mmol/g) at 298 K and 1 bar. The multi-sigmoidal adsorption profile, arising from solid-state chemical transformation into well-defined compounds of formulas {Ni 2 (PhCOS) 4 (NH 3 ) n } (n = 1, 8 and 16), provides a large pressure-swing working capacity (11.4 mmol/g between 0.1 and 1.0 bar) and enables complete, energy-efficient regeneration under remarkably mild conditions (60–80 °C). The transformation was associated with drastic changes in the coordination environment of Ni centers yet was fast and fully reversible. Phase transformation-induced self-fragmentation generates hierarchical diffusion pathways, driving rapid kinetics (50% uptake in 95 s). Furthermore, the complex demonstrates outstanding ambient moisture tolerance, 10-cycle durability, scalable one-pot synthesis exceeding 60 g (81% yield), and practical cartridge-level storage (+36wt% mass increase), demonstrating dynamic molecular complexes as a practical platform for gas management.
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BibTeX
@misc{ouay2026fully,
title = {{Fully Reversible High-Capacity Ammonia Storage in a Series of Phase-Transformable Molecular Nickel Thiocarboxylates}},
author = {Benjamin Le Ouay and Yume Matsumoto and Ao Zhang and Manami Ueno and Ryo Ohtani and Masaaki Ohba},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15009231/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009231/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Fully Reversible High-Capacity Ammonia Storage in a Series of Phase-Transformable Molecular Nickel Thiocarboxylates
AU - Benjamin Le Ouay
AU - Yume Matsumoto
AU - Ao Zhang
AU - Manami Ueno
AU - Ryo Ohtani
AU - Masaaki Ohba
PY - 2026
DA - 2026/09/22
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009231/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009231/v1
AB - Ammonia (NH 3 ) is an indispensable chemical commodity in modern society, but its nature as a toxic and corrosive gas makes its storage and transport difficult. Here, we report non-porous molecular nickel thiobenzoate [Ni 2 (PhCOS) 4 ] and derivatives, as a distinct class of phase-transformable adsorbents for reversible and high-density ammonia storage in ambient conditions. Despite lacking intrinsic porosity, [Ni 2 (PhCOS) 4 ] presented excellent sorption capacity of 23.5 mmol/g (effective reversible capacity: 22.0 mmol/g) at 298 K and 1 bar. The multi-sigmoidal adsorption profile, arising from solid-state chemical transformation into well-defined compounds of formulas {Ni 2 (PhCOS) 4 (NH 3 ) n } (n = 1, 8 and 16), provides a large pressure-swing working capacity (11.4 mmol/g between 0.1 and 1.0 bar) and enables complete, energy-efficient regeneration under remarkably mild conditions (60–80 °C). The transformation was associated with drastic changes in the coordination environment of Ni centers yet was fast and fully reversible. Phase transformation-induced self-fragmentation generates hierarchical diffusion pathways, driving rapid kinetics (50% uptake in 95 s). Furthermore, the complex demonstrates outstanding ambient moisture tolerance, 10-cycle durability, scalable one-pot synthesis exceeding 60 g (81% yield), and practical cartridge-level storage (+36wt% mass increase), demonstrating dynamic molecular complexes as a practical platform for gas management.
ER -