%P 899-902 %I Elsevier %X XPS and XAES studies of air-exposed Mg2Cu and Mg2Ni alloys showed surface decomposition and preferential segregation of Mg by the influence of oxygen and moisture. The segregated magnesium is mostly present as oxide and hydroxide on the surface. The second metallic component namely Ni or Cu is also present in the oxidized state. The passivation of these alloys arises by the oxidation of the transition metal component. We suggest that the activation of these alloys involves reduction of the oxidized 3d elements and the formation of metallic clusters. %L catalysis396 %D 1989 %N 12 %V 14 %A Selvam P %A Viswanathan B %A Srinivasan V %J International Journal of Hydrogen Energy %T XPS and XAES studies on hydrogen storage magnesium-based alloys