The task of the Pavia H2 Lab was the characterization of the materials concerning their thermodynamic and kinetic H2 sorption properties, in order to select the systems with characteristics as close as possible to those required for practical applications.
To this aim, and considering the characteristics of Mg-based materials, the Pavia H2 Lab developed:
an effective activation procedure, made of subsequent charging/discharging cycles at 350 °C and hydrogen pressure = 35 bar/ 1 bar (the number and the duration of the cycles decreases with the goodness of the storage system);
a tunable characterization procedure, made of temperature programmed absorption/desorption runs, isothermal charging/discharging cycles and Pressure – Composition Isothermal measurements (PCI), in order to obtain simultaneously information on all the parameters needed for the materials selection (• the gravimetric capacity of the system; • the reversibility of the sorption reactions; • the minimum temperature at which full absorption/desorption takes place, • the kinetic of absorption/desorption at the minimum working temperature; • the number of the sorption steps and their equilibrium pressures; • the cycling ability of the systems).
SEM and XRPD analyses were realized to study the morphological and compositional characteristics of the samples and to obtain information on the sorption mechanism active upon absorption/desorption.