International Journal of Hydrogen Energy, Vol.38, No.34, 14704-14714, 2013
Non-isothermal kinetics and in situ SR XRD studies of hydrogen desorption from dihydrides of binary Ti-V alloys
Phase transformations during dynamic dehydrogenation of Ti1-x,VxH2 (x = 0.1; 0.2; 0.3) were studied using in situ Synchrotron X-Ray Diffraction (SR XRD) and non-isothermal kinetics experiments. The main dehydrogenation path for gamma-Ti1-xVxH2 was found to be gamma -> delta -> beta -> beta(alloy). Body-centred tetragonal delta-hydride was found to be an intermediate phase of the gamma -> beta transformation in Ti-0 8-0.9V0.1-0.2H2. TDS, in situ SR XRD and isoconversional kinetics studies showed that hydrogen desorption from Ti1-xVxH2 is composed of simultaneous reactions taking place between 300 and. 600 degrees C. The effective activation energy of hydrogen desorption depends on the vanadium contents and the reaction pathway, increasing from 21 kJ/mol H-2 (gamma -> delta) to 60-110 kJ/mol H-2 (delta -> beta). Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Titanium;Vanadium;Metal hydride;In situ synchrotron X-ray diffraction;Thermal desorption spectroscopy;Isoconversional kinetics