Clathrate hydrates can be reasonable choices for high-density hydrogen storage into compact host media, which is an essential task for hydrogen-based future society. However, conventional storage scheme where aqueous solution is frozen with hydrogen gas was impractically slow for practical use. Here we propose a much faster scheme where hydrogen gas was directly charged into hydrogen-free, crystalline hydrate powders. The storage kinetics was observed in situ by nuclear magnetic resonance (NMR) spectroscopy in a pressurized tube cell. At pressures up to 20 MPa the storage was complete within 80 minutes, as observed by growth of stored-hydrogen peak into the hydrate. Since the rate-determining step of current storage scheme is body diffusion of hydrogen within the crystalline hydrate media, we have measured the diffusion coefficient of hydrogen molecules using the pulsed field gradient NMR method. The results show that at temperatures down to 250 K the stored hydrogen is highly mobile, so that the powdered hydrate media should work well even in cold environments. Compared with more prevailing hydrogen storage media such as metal hydrides, the clathrate hydrate could offer even more advantages: It is free from hydrogen embrittlement, more chemically durable, more environmentally benign, as well as economically quite affordable.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/1096 |
| Date | 07 1900 |
| Creators | Okuchi, Takuo, Moudrakovski, Igor L., Ripmeester, John A. |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
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