Hydrogen storage capacities

Hou et al. [73] considered small "carbon islands" as the main hydrogen-adsorption sites in an MWNT. The hydrogen-storage capacity of a CNT varies widely and the reason for such a variation is not clear, possibly caused by the impurity such as metal catalysts or amorphous carbon. It is not clear yet how the metallic catalyst particles, which are used during the preparation of nanotube samples, affect the hydrogen-storage capacity of nanotubes. 

Xu, W.-C., K. Takahashi, Y. Matsuo, Y. Hattori, M. Kumagai, S. Ishiyama, K. Kanekoc, S. Iijima, Investigation of hydrogen storage capacity of various carbon materials, bit.. Hydrogen Energ. 32(13), 2504-2512,2007 (available online). 

Figure 6. Total hydrogen storage capacity on the basis of a 1 I container, (a) at 298 K for the activated carbon KUA5 (b) at 77 K for an activated carbon monolith.

Z. Yang, Y. Xia, and R. Mokaya, Enhanced Hydrogen Storage Capacity of High Surface Area Zeolite-like Carbon Materials, J. Am. Chem. Soc., 129, 1673-1679 (2007). 

B. Buczek, L. Czepirski, and J. Zietkiewicz, Improvement of hydrogen storage capacity for active carbon, Adsorption, 11, 877-880 (2005). 

The Li-Mg-B-N-H structure possesses storage capacity of more than 10 wt.% at around 150-200 "C. However, the reversibility of the hydrogen sorption characteristics was determined using pressure-composition isotherms as shown in Figure 6. From this study, we found reversible hydrogen absorption-desorption behavior (-3-4 wt.%) of the new complex hydride Li-Mg-B-N-H. The improvement in temperature and reversible hydrogen storage capacity were unaffected even after ten... 

Yang SJ, Choi JY, Chae HK, Cho JH, Nahm KS, Park CR. Preparation and enhanced hydrostability and hydrogen storage capacity of CNT MOF-5 hybrid composite, Chem. Mater. 2009, 21, 1893-1897. 

Due to the high hydrogen storage capacity of the ammonia molecule (17.7 wt% equal to an energy density of 4,318 Wh kg 1), its decomposition is intensely investigated for COx-free hydrogen production for mobile fuel cell applications [146]. However, compared with the well-established Haber Bosch process for ammonia synthesis, its decomposition is underdeveloped and requires substantial improvements before it can be considered as a practical contribution to the energy supply toolbox. 

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