Self-ignition combustion synthesis of oxygen-doped TiFe

This paper describes the Self-Ignition Combustion Synthesis (SICS) of the hydrogen storage alloy Ti1.15FeOx (x = 0, 0.024, and 0.050) in a hydrogen atmosphere and the obtained product's hydrogenation properties. Ti, Fe, and α-Fe2O3 powders were mixed to produce Ti1.15FeOx and uniformly heated to the eutectic temperature 1358 K for self-ignition, which occurred after the hydrogenation and decomposition of Ti. The X-ray diffraction results for the final product had TiFeH0.06 and Fe2Ti as the major and minor phases, respectively. The hydrogen storage capacity of the product at a hydrogen pressure of 5 MPa was 1.18–1.50 m%. As the value of x increased, the capacity gradually decreased. However, the initial hydrogenation kinetics of the product improved. In contrast, the equilibrium pressure for the product was almost unaffected. These results demonstrate that SICS is quite effective for producing O-doped TiFe alloys as well as TiFe without rare metal. The procedure offers many benefits of releasing tough activation treatment, minimizing operation time, and saving energy.