Hydride cycle formation of ternary alloys in TiVMn system and their interaction with hydrogen

• Hydride cycle mode was used to synthesize three triple alloys in TiVMn system.
• These alloys interacted with hydrogen in combustion and short-time activation modes.
• TiV1.2Mn0.8H3.7, TiV0.8Mn1.2H2.35 and Ti0.37V0.38Mn0.25H1.56 hydrides formed.
• X-ray evidenced the presence in the hydrides of mono- and di-hydride phases.
• Hydride cycle is an easy and affordable mode for synthesis of multicomponent alloys.

Metal hydrides are promising as compact and safe hydrogen storage materials. Among them, the hydrides of ternary and more complex alloys are provided with properties required in modern hydride material science. In this work, the mechanism of formation of ternary alloys in TiVMn system in the “hydride cycle” mode was investigated. TiV1.2Mn0.8, TiV0.8Mn1.2, and Ti0.37V0.25Mn0.25 alloys were synthesized, their interaction with hydrogen was observed in: a) combustion mode; b) at rather low temperature (25–50 °C) after short-term activation. X-ray, DTA and chemical analysis evidenced that the hydrogen interaction with the alloys, formed in both modes, resulted in the formation of TiV1.2Mn0.8H3.7, TiV0.8Mn1.2H2.35 and Ti0.37V0.25Mn0.25H1.56 hydrides of identical structure, hydrogen content and thermal properties. These hydrides were stable at sorption-desorption cycling and during long-term (1 year) storage. Conclusion: the “hydride cycle” is an easy and affordable method of creation the ternary alloys with high hydrogen sorption properties, needed in hydrogen accumulators.