HYDROGENATION OF CHOSEN MgMXN INTERMETALLICS (X=Al, Ga, In, Si, Sn)

Hydrogen sorption in chosen intermetallics MgmXn (Mg17Al12, Mg2Ga, mixture of beta-Mg-In phases, Mg2Si and Mg2Sn) formed by magnesium and elements from the 13th (X: Al, Ga, In) and 14th (X: Si, Sn) groups was studied between the room temperature and T = 350 degrees C. Hydrogen pressure p varied from 10(-3) MPa to 6 MPa. Hydrogen solubility in alpha phase (solid solution of hydrogen in MgmXn before the hydride phase was nucleated) was close to hydrogen solubility in pure Mg. Concentration c(H) of hydrogen solved in MgmXn depended linearly on pressure p; dependence of cH on temperature T was relatively weak. MgH2 was the main hydrogen storage phase in all the compounds MgmXn. Nucleation of MgH2 at 350 was observed at pressure above approximately 1 MPa in Mg17Al12 and above 2 Ma in other compounds. Maximum values of c(H) in hydride-containing compounds MgmXn detected at T = 350 degrees C depended on the stability of MgmXn.Hydrogen sorption in chosen intermetallics MgmXn (Mg17Al12, Mg2Ga, mixture of beta-Mg-In phases, Mg2Si and Mg2Sn) formed by magnesium and elements from the 13th (X: Al, Ga, In) and 14th (X: Si, Sn) groups was studied between the room temperature and T = 350 degrees C. Hydrogen pressure p varied from 10(-3) MPa to 6 MPa. Hydrogen solubility in alpha phase (solid solution of hydrogen in MgmXn before the hydride phase was nucleated) was close to hydrogen solubility in pure Mg. Concentration c(H) of hydrogen solved in MgmXn depended linearly on pressure p; dependence of cH on temperature T was relatively weak. MgH2 was the main hydrogen storage phase in all the compounds MgmXn. Nucleation of MgH2 at 350 was observed at pressure above approximately 1 MPa in Mg17Al12 and above 2 Ma in other compounds. Maximum values of c(H) in hydride-containing compounds MgmXn detected at T = 350 degrees C depended on the stability of MgmXn.