Palladium Hydride III. Thermodynamic Study of pd2 D from 150 to 3030 K. evidence for the Tetrahedral pd H4, Structure in Palladium Hydride

摘要

Reasonable barrier heights and. frequencies have been calculated to fit tor a model based on PdH4 • 7Pd at low temperatures. To explain the heat capacities above 120°K, a dissociation process is postulated which involves a decrease in the average number of hydrogen bonds as the temperature is raised.nHydrogen diffusion through palladium is conceived as a movement of hydrogen atoms by a continuous combination of (1) rotation about a parent palladium atom and (2) bonding to, and subsequent rotation about, this new palladium atom. A new theory has been developed to explain the phase separation and hysteresis in the absorption isotherm.