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Hydrogen storage properties of Ti 1− x Sc x MnCr Laves phase alloys
Author(s) -
Li Wuhui,
Wu Erdong,
Ma Ping,
Sun Kai,
Chen Dongfeng
Publication year - 2012
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.2971
Subject(s) - laves phase , hydrogen storage , alloy , hydride , differential scanning calorimetry , hydrogen , materials science , disproportionation , lattice constant , desorption , analytical chemistry (journal) , metallurgy , intermetallic , chemistry , thermodynamics , diffraction , metal , adsorption , catalysis , organic chemistry , chromatography , biochemistry , physics , optics
SUMMARY The hydrogen storage properties of Ti 1− x Sc x MnCr ( x = 0.05, 0.10, 0.15, 0.22, 0.27 and 0.32) alloys are studied by pressure‐composition isotherms at 0–60 °C and 1 kPa–4 MPa. The relevant crystal structures of the alloys and their hydrides are examined by the X‐ray diffraction and electron microscopy. The alloys are basically C14 type Laves phase with slightly different lattice parameters owing to the difference in composition. Except for x = 0.05 alloy, the bulk samples of these alloys can be easily activated under ambient conditions and attain the maximum hydrogen storage capacities during the initial hydrogenation. As Sc content increases, the hydrogen storage capacity of the alloy increases whereas the pressure of the absorption/desorption plateau decreases. No hydrogen‐induced disproportionation is observed, and the hydrogen‐induced defects and pulverization are not severe after hydriding/dehydriding cycles of these alloys. The Ti 0.78 Sc 0.22 MnCr alloy exhibits the best reversible hydrogen storage capacity of ~2 wt% in between 1 and 4000 kPa at room temperature. Except for the x = 0.32 alloy, the average thermodynamic values of |Δ H | and |Δ S | in the system increase approximately linearly with Sc content in the alloys. The thermogravimetry‐differential scanning calorimetry (TG‐DSC) on desorption of the hydride of Ti 0.68 Sc 0.32 MnCr indicates that the thorough release of hydrogen in the alloy can be achieved at 658 K. Copyright © 2012 John Wiley & Sons, Ltd.