Reactivity of magnesium to hydrogen: A high-pressure analysis of the dissolution enthalpy

Abstract

The temperature variation of the hydrogen solubility in magnesium in equilibrium with H2 gas has been measured mostly with use of a resistometric method, for pressures ranging between 0.1 and 12 MPa. The relative partial enthalpy per gram atom of the interstitially dissolved gas was inferred to be 58±5 kJ mol−1 (0.60±0.05 eV). This experimental finding is compared with previous data. The reaction of magnesium with traces of oxygen or moisture and the possible influence of this effect on the result are discussed also. A further point of discussion deals with the proper separation between hydrogen dissolution and hydride formation.