The structure of the V–15Ni at.% alloy before and after hydrogen permeability tests was investigated by means of XRD and SEM with EDS analysis. We have found that decomposition of supersaturated V-based solid solution with variable Ni content occurred during testing. The volume fraction of the solid solution decreased and the fraction of V3Ni phase increased during permeability testing, thus bringing the alloy to nearly equilibrium. The membrane without Pd coating showed satisfactory hydrogen fluxes with a significant impact of the surface dissociation rate of hydrogen. The shape of hydrogen permeation curves at the downstream side of the membrane at various temperatures was unusual. We attribute it to the high concentration of dissolved hydrogen in the metal lattice and its effect on the hydrogen diffusivity and solubility. In addition, the multiphase structure with non-uniform distribution of nickel both between the phases and within the BCC solid solution (and, consequently, different hydrogen concentrations) may cause dilatation or compressing effect on neighbouring micro-volumes of the alloy.

Original languageEnglish
Pages (from-to)27492-27498
Number of pages7
JournalInternational Journal of Hydrogen Energy
Volume44
Issue number50
Early online date21 Sep 2019
DOIs
StatePublished - 18 Oct 2019

    Research areas

  • Hydrogen permeability, Microstructure, Supersaturated BCC solid solution, V-Ni alloys, PERMEATION CHARACTERISTICS, PURIFICATION, MEMBRANES, DIFFUSION

    Scopus subject areas

  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Fuel Technology
  • Renewable Energy, Sustainability and the Environment

ID: 47619716