Carbon nanotube materials for hydrogen storage
- National Renewable Energy Lab., Golden, CO (United States)
Hydrogen burns pollution-free and may be produced from renewable energy resources. It is therefore an ideal candidate to replace fossil fuels as an energy carrier. However, the lack of a convenient and cost-effective hydrogen storage system greatly impedes the wide-scale use of hydrogen in both domestic and international markets. Although several hydrogen storage options exist, no approach satisfies all of the efficiency, size, weight, cost and safety requirements for transportation or utility use. A material consisting exclusively of micropores with molecular dimensions could simultaneously meet all of the requirements for transportation use if the interaction energy for hydrogen was sufficiently strong to cause hydrogen adsorption at ambient temperatures. Small diameter ({approx}1 mm) carbon single-wall nanotubes (SWNTs) are elongated micropores of molecular dimensions, and materials composed predominantly of SWNTs may prove to be the ideal adsorbent for ambient temperature storage of hydrogen. Last year the authors reported that hydrogen could be adsorbed on arc-generated soots containing 12{Angstrom} diameter nanotubes at temperatures in excess of 285K. In this past year they have learned that such adsorption does not occur on activated carbon materials, and that the cobalt nanoparticles present in their arc-generated soots are not responsible for the hydrogen which is stable at 285 K. These results indicate that enhanced adsorption forces within the internal cavities of the SWNTs are active in stabilizing hydrogen at elevated temperatures. This enhanced stability could lead to effective hydrogen storage under ambient temperature conditions. In the past year the authors have also demonstrated that single-wall carbon nanotubes in arc-generated soots may be selectively opened by oxidation in H{sub 2}O resulting in improved hydrogen adsorption, and they have estimated experimentally that the amount of hydrogen stored is {approximately}10% of the nanotube weight.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- OSTI ID:
- 456745
- Report Number(s):
- NREL/CP-430-21968-Vol.2; CONF-9605195-Vol.2; ON: DE97001438; TRN: 97:001171-0010
- Resource Relation:
- Conference: 1996 annual hydrogen peer review for DOE, Miami, FL (United States), 1-3 May 1996; Other Information: PBD: Oct 1996; Related Information: Is Part Of Proceedings of the 1996 US DOE hydrogen program review. Volume 2; PB: 268 p.
- Country of Publication:
- United States
- Language:
- English
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