Low temperature hydrogen and deuterium isotherms for Pd and some of its binary alloys

Abstract

This research demonstrates that hydrogen (deuterium) isotherms for Pd and its alloys can be measured down to quite low temperatures opening up new possibilities for the characterization of these systems. Deuterium isotherms are determined in this research down to 233 K and to 218 K for the Pd0.95Rh0.05 and Pd0.90Rh0.10 alloys, respectively. At low temperatures and moderate pressures, Pd and its alloys absorb significantly more H or D than at, e.g., 298 K. For example, at 218 K and ≈ 1 bar, the Pd0.90Rh0.10 alloy absorbs D up to (D/Pd0.90Rh0.10) ≈0.8, mol ratio whereas the ratio is ≈ 0.70 at 298 K. The rate of attainment of equilibrium was relatively fast at the low temperatures,e.g., at 218 K equilibrium of Pd with D2 was established in ≈10 m.