1. Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
2. Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, Canada K1A 0R6
3. Present address: Conversion Process Research Center, Korea Institute of Energy Research, PO Box 103, Jang-dong, Yuseong-gu, Daejeon 305-343, Republic of Korea

Correspondence to: Huen Lee¹John A. Ripmeester² Correspondence and requests for materials should be addressed to H.L. (Email: h_lee@kaist.ac.kr) or J.A.R. (Email: John.Ripmeester@nrc-cnrc.gc.ca).

The storage of large quantities of hydrogen at safe pressures¹ is a key factor in establishing a hydrogen-based economy. Previous strategies—where hydrogen has been bound chemically², adsorbed in materials with permanent void space³ or stored in hybrid materials that combine these elements³—have problems arising from either technical considerations or materials cost^{2, 3, 4, 5}. A recently reported^{6, 7, 8} clathrate hydrate of hydrogen exhibiting two different-sized cages does seem to meet the necessary storage requirements; however, the extreme pressures ( 2 kbar) required to produce the material make it impractical. The synthesis pressure can be decreased by filling the larger cavity with tetrahydrofuran (THF) to stabilize the material⁹, but the potential storage capacity of the material is compromised with this approach. Here we report that hydrogen storage capacities in THF-containing binary-clathrate hydrates can be increased to 4 wt% at modest pressures by tuning their composition to allow the hydrogen guests to enter both the larger and the smaller cages, while retaining low-pressure stability. The tuning mechanism is quite general and convenient, using water-soluble hydrate promoters and various small gaseous guests.

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.