Hydrogenation properties of five-component Mg ₆₀ Ce ₁₀ Ni ₂₀ Cu ₅ X ₅ (X= Co, Zn) metallic glasses

Hydrogenation properties of two five-component Mg ₆₀ Ce ₁₀ Ni ₂₀ Cu ₅ X ₅ (X = Co, Zn) metallic glasses have been studied. Using high-pressure differential scanning calorimetery (HP-DSC) under hydrogen atmosphere and hydrogenation kinetics study, it is demonstrated that alloying with Zn shows negligible impact on the hydrogenation kinetics and storage capacity of the Mg–Ce–Ni–Cu metallic glass, however, alloying with Co remarkably improves the hydrogenation kinetics and storage capacities. Apparent activation energies for hydrogenation are calculated to be 64.4 kJ/mol, and 107.2 kJ/mol, for the Mg ₆₀ Ce ₁₀ Ni ₂₀ Cu ₅ Co ₅ and Mg ₆₀ Ce ₁₀ Ni ₂₀ Cu ₅ Zn ₅ metallic glasses, respectively. Theoretical calculations are performed to understand the atomic structure of the five-component metallic glasses. It shows that the overall, Mg–Mg pair and Mg–Ni pair distribution functions (PDFs) of the Mg ₆₀ Ce ₁₀ Ni ₂₀ Cu ₅ Co ₅ and Mg ₆₀ Ce ₁₀ Ni ₂₀ Cu ₅ Zn ₅ metallic glasses are almost the same, indicating that geometry issue is not a key factor on influencing the hydrogenation properties of the studied Mg-based metallic glasses. It is proposed that chemical composition is the key to improve the hydrogenation properties of Mg-based metallic glasses.