Hydrogen Release from Oxidized Titanium Hydride

Hydrogen storage is one of the most important industrial applications of titanium hydride (TiH2). A critical issue is the hydrogen release rate that strongly depends on the surface structure of TiH2 particles. This work reports the results of an experimental campaign carried out on TiH2 powders submitted to heat treatments in air at different temperatures and treatment times. After each heat treatment the TiH2 powders were examined by X-ray diffraction (XRD) and the results evidenced that the surface layer consists of TiO2 and Ti2O. Titanium oxide formation has been monitored by XRD at high temperature. Hydrogen release during heating of oxidized powders was investigated through temperature programmed desorption (TPD). Residual hydrogen in TiH2 depends on the specific treatment: higher temperature and soaking time of the treatment, lower its content.