On Palladium‐Hydrogen

The isothermal absorption of hydrogen by palladium was studied at temperatures ranging from 0° C. to 138° C. The curves show the same general characteristics as the isotherms determined by previous investigators, i.e., a preliminary rise, a central horizontal portion followed by an almost vertical rise upon saturation of the palladium with hydrogen. The curves do not show definite evidence of formation of a compound between palladium and hydrogen. The rates of absorption were studied at the same temperature range as the absorption isotherms. The amount of hydrogen taken up by palladium decreases with increased temperature and the decrease is a linear function of the temperature from 0° C. to 82° C., while above 82° C. the amount of hydrogen taken up diminishes rapidly. The shrinkage of the palladium foil affected the rate of absorption at temperatures below 56° C. but had no effect at higher temperatures. The change in dimensions of palladium foil with continued hydrogenation was studied extensively. There was increase in chemical activity with deformation of the palladium, until, after 90 hydrogenations, the hydrogen in palladium‐hydrogen united with oxygen with explosive violence. There was no temperature rise when the metal was put in a vacuum or in an atmosphere of nitrogen. When the metal was put in air or oxygen water was formed on the sides of the tube.