Theoretical aspects of the absorption of hydrogen by palladium and its alloys. Part 2.—Possible effects of lattice expansion on the solubility of hydrogen in palladium

Abstract

A model is developed which takes account of possible changes in strain energy as a function of hydrogen content when hydrogen is absorbed by palladium. Using independent data the attractive interaction between absorbed atoms is calculated and is found to be in good agreement with the value obtained from isothermal data. The model predicts a limiting solubility at H/Pd < 1.0 and a minimum heat of solution of hydrogen at H/Pd ≈ 0.6, in agreement with experiment. The possible extension of the model to some other metal-hydrogen systems is discussed.