The Role of Al on the Thermodynamics of Hydrogen Absorption/Desorption by Some Ternary Pd-M-Al Alloys where M=Rh, Ni, Pt, Cr, Ag.

Journal Article · Wed Apr 10 04:00:00 EDT 2002 · J. Alloys and Compounds

OSTI ID:799712

Shanahan, K L

The solution of hydrogen and hydride formation in FCC substitutional solid solution Pd0.9Rh0.1-xAlx alloys have been examined. In contrast to some other Pd ternary alloys, a linear relation does not obtain between the H capacity and x for the Pd0.9Rh0.1-xAlx alloys investigated here where the H capacity of the alloys is estimated from the H content of the steeply rising part of the isotherms in the hydride phase regions. A linear increase of the dilute phase H solubility with x for these Pd0.9Rh0.1-xAlx alloys does, however, obtain for these alloys. Although Pd-Rh binary alloys have broader plateaux than does Pd itself, small amounts of Al substituted into Pd0.85Rh0.15 or Pd0.80Rh0.20 alloys can reduce or eliminate the two phase regions, the plateaux; there is, however, not much effect on the dilute phase solubilities. For example, small amounts of Al substituted into the Pd0.85Rh0.15 or Pd0.80Rh0.20 alloys eliminate the plateaux. On the other hand, alloying Pd with Al to form binary alloys with Xal equals 0.015 or 0.030 does not eliminate the plateaux which are present in these binary alloys up to Xal equals 0.075 (298 K). Small amounts of Al substitution do not have such a dramatic effect on the plateau widths of the Pd0.90Ni0.10 and Pd0.80Ni0.20 alloys and similarly substitution of Al into Pd-Cr and Pd-Ag alloys does not introduce any anomalous effects into the isotherms.

• Research Organization: Savannah River Site (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC09-96SR18500
• OSTI ID: 799712
• Report Number(s): WSRC-MS-2002-00278
• Journal Information: J. Alloys and Compounds, Journal Name: J. Alloys and Compounds
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
ALLOYS
CAPACITY
HYDRIDES
HYDROGEN
ISOTHERMS
SAVANNAH RIVER PLANT
SOLID SOLUTIONS
SOLUBILITY
THERMODYNAMICS