Decomposition kinetics study of zirconium hydride by interrupted thermal desorption spectroscopy

• Interrupted TDS was applied to investigate the mechanism of ZrH2 decomposition.
• The activation energies for the five desorption peaks were determined.
• The origins of the five desorption peaks were identified.
• The γZrH phase was observed at ambient conditions.

Thermal desorption kinetics of zirconium hydride powder were studied using thermogravimetry and simultaneous thermal desorption spectroscopy. The activation energies for observed desorption peaks were estimated according to Kissinger relation. The intermediate phase composition was studied using X-ray diffraction by rapid cooling on different stages of heating. The origins of the peaks were described as the equilibrium hydrogen pressure of a number of consecutive phase regions that decomposition reaction passed through. The zirconium monohydride γZrH was observed for extended periods of time at ambient conditions, which has been supposed to be metastable for a long time.