ISOBARIC AND ISOTHERMAL DSC MEASUREMENTS OF METAL-HYDROGEN SYSTEMS

The reversible formation reaction of hydrides from metals and hydrogen is used as a prototype of a gas-solid heterogeneous reaction in order to show that a sufficient thermodynamic and kinetic characterization of such reactions can be achieved by isothermal and isobaric DSC measu rements. The isobaric measurements essentially provide thermodynamic d ata such as reaction enthalpy, yield and the pressure-temperature rela tion. On the other hand, the isothermal measurements can be used for k inetic evaluation due to the small number of parameters. Results are g iven for the Pd-H and La-Mg-H systems.