Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Investigation of the hyperstoichiometric Zr/sub 1-x/Ti/sub x/CrFe/sub y/sup -/H/sub 2/ system

Journal Article · · J. Solid State Chem.; (United States)
The pressure-composition isotherms and relevant crystallographic, thermodynamic, and kinetic parameters are presented and discussed for the Zr/sub 1-x/Ti/sub x/CrFe/sub y/-H/sub 2/ system with x = 0.1, 0.3 and y = 1.2-1.4. The hyperstoichiometric iron was observed to have a profound effect on the equilibrium dissociation pressure, elevating the plateau pressure several times over that for the corresponding Zr/sub 1-x/Ti/sub x/CrFe hydride. The hydrogen capacities of these quaternary intermetallics are quite high, the volumetric capacity being 1.21 to 1.32 with respect to that of liquid hydrogen, the weight capacity 159.9-178.9 cm/sup 3/ H/sub 2//g alloy. The enthalpies and entropies of dissociation are in the range 27.3-31.1 kJ/mole H/sub 2/ and 100-107.2 J/K mole H/sub 2/, respectively. The dehydrogenation process was found to follow first-order kinetics with an activation energy 43.4 kJ/mole H/sub 2/. The diffusion of atomic hydrogen was considered to be the rate-determining step.
Research Organization:
Univ. of Pittsburgh, PA
OSTI ID:
6540355
Journal Information:
J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Journal Issue: 1 Vol. 67:1; ISSN JSSCB
Country of Publication:
United States
Language:
English