Deoxidization mechanism of hydrogen in TiH2 dehydrogenation process

• The effect of oxide thickness on the H2O release in TiH2 is investigated.
• The hydrogen atoms remove the part oxygen of surface oxide film of TiH2.
• The thicker the Ti oxides film, the smaller the amount of deoxygenation to form H2O.
• The H atoms mainly remove the O in metastable Ti2O3, and then part of the O in TiO2.

The different oxide film thickness of TiH2 powders are investigated by the different pre-oxidized temperature. The results of thermogravimetric-mass spectroscopy analysis and X-ray photoelectron spectroscopy indicate that the hydrogen atoms remove the part oxygen of surface oxide film and have the surface cleaning effects in the dehydrogenation process. The thicker the Ti oxides film on the surface of TiH2 powder, the smaller the amount of deoxygenation to form water. It is possible in thermodynamics that the hydrogen atoms in TiH2 powder mainly remove the oxygen in metastable Ti2O3, and then part of the oxygen in TiO2.