Abstract
Ball-milled hydrogenated graphite-iron materials have attracted interest as possible hydrogen storage media because of theoretically estimated hydrogen capacities of about 10wt%. However, such a value needs to be experimentally verified. In this work, graphite-0.5wt% Fe was milled under 3bar hydrogen in a tungsten carbide milling pot. The effect of iron on the microstructure and hydrogen storage properties of milled graphite was investigated by thermal gravimetric analysis-mass spectrometry, X-ray diffraction, and transmission electron microscopy. When a 10-hour milled graphite with 0.5wt% Fe sample was heated under argon to 990°C, 9.6wt% of hydrogen was released, which is almost double than that for a graphite sample with no iron (5.5wt% hydrogen). The addition of iron also was found to reduce the onset temperature of hydrogen desorption by 50 to 350°C. However, for a longer milling time of 40hours, the amount of hydrogen desorbed for graphite-0.5wt% Fe decreased, and methane also was detected. The results suggest that iron carbide produced during milling plays a catalytic role, increasing the hydrogen storage capacity and lowering the onset temperature of hydrogen desorption.
Original language | English |
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Pages (from-to) | 720-725 |
Number of pages | 6 |
Journal | International Journal of Energy Research |
Volume | 37 |
Issue number | 7 |
DOIs | |
Publication status | Published - 2013 Jun 10 |
Keywords
- Ball milling
- Graphite
- Graphite-iron
- Hydrogen
- Hydrogen storage
- Iron carbide
- Methane
- Milling time
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Fuel Technology
- Nuclear Energy and Engineering
- Renewable Energy, Sustainability and the Environment