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Hydrogen storage properties of ball‐milled graphite with 0.5 wt% Fe
Author(s) -
Zhang Yinghe,
Book David
Publication year - 2011
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.1903
Subject(s) - hydrogen storage , graphite , hydrogen , carbide , materials science , ball mill , tungsten carbide , desorption , metallurgy , microstructure , chemical engineering , analytical chemistry (journal) , alloy , chemistry , adsorption , organic chemistry , engineering
SUMMARY Ball‐milled hydrogenated graphite‐iron materials have attracted interest as possible hydrogen storage media because of theoretically estimated hydrogen capacities of about 10 wt%. However, such a value needs to be experimentally verified. In this work, graphite‐0.5 wt% Fe was milled under 3 bar 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 0.5 wt% Fe sample was heated under argon to 990 °C, 9.6 wt% of hydrogen was released, which is almost double than that for a graphite sample with no iron (5.5 wt% 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 40 hours, the amount of hydrogen desorbed for graphite‐0.5 wt% 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. Copyright © 2011 John Wiley & Sons, Ltd.