Hydrogen absorption properties of intermetallic compounds in the Au-Zr binary system

The present work reports about hydrogen absorption properties of four intermetallic compounds Au2Zr, Au10Zr7, AuZr2 and AuZr3 in the Au-Zr binary system. which were studied by means of differential scanning calorimetry (DSC), hydrogen-storage capacity measurement and powder X-ray diffraction (XRD). A single exothermic peak, which is assigned to hydrogen absorption, appeared at a lower temperature for the intermetallic compound with increasing Au content. indicating a catalytic effect of gold on hydrogenation process;, the amount of the exothermic heat linearly increased as a function of Zr content regardless of different structure between AuZr3 (cubic) and other intermetallic compounds (tetragonal). Hydrogen-storage capacity measurement has also confirmed that the intermetallic compounds with higher Zr content afford more hydrogen-storage capacity. Powder XRD confirmed that no structural change was induced under the present hydrogenation conditions, but only a solid solution with hydrogen was formed for Au2Zr, Au10Zr7 and AuZr2. On the other hand, an unidentified hydride phase was formed in coexistence with the solid solution with hydrogen for cubic AuZr3. (C) 2009 Elsevier B.V. All rights reserved.