Tailoring the equilibrium hydrogen pressure of TiFe via vanadium substitution

Jee Yun Jung, Young Su Lee, Jin Yoo Suh, Joo Youl Huh, Young Whan Cho

    Research output: Contribution to journalArticlepeer-review

    34 Citations (Scopus)

    Abstract

    We present that the equilibrium hydrogen pressure of titanium iron (TiFe) alloy, a room-temperature hydrogen storage material, can be tailored via vanadium alloying. While many 3d transition metal alloying elements (e.g., Mn, Cr, Co, and Ni) typically replace the Fe sublattice in TiFe, vanadium can replace both the Ti and Fe sublattices. Density functional theory calculation predicts that the substitution of Ti with V yields a unique effect: the equilibrium pressures of TiFe/TiFeH (P1) and TiFeH/TiFeH2 (P2) are closer, resulting in a decreased P2/P1 ratio. Experimental pressure-composition isotherms confirm this theoretical prediction. The lower P2/P1 is beneficial because the two-step TiFe hydrogenation reactions can be contained within a narrow pressure range. In contrast, the substitution of V for Fe lowers both P1 and P2, but lowers P1 more, resulting in a higher P2/P1 ratio. The contrasting effects contingent on the substitution site is a crucial factor in alloy design. It highlights the significance of vanadium as a versatile alloying element that modifies the hydrogen storage property of TiFe.

    Original languageEnglish
    Article number157263
    JournalJournal of Alloys and Compounds
    Volume854
    DOIs
    Publication statusPublished - 2021 Feb 15

    Bibliographical note

    Funding Information:
    This study was supported by the Korea Institute of Science and Technology (grant number 2E30201 ).

    Publisher Copyright:
    © 2020 Elsevier B.V.

    Keywords

    • Computer simulations
    • Hydrogen absorbing materials
    • Metals and alloys
    • Thermodynamic properties

    ASJC Scopus subject areas

    • Mechanics of Materials
    • Mechanical Engineering
    • Metals and Alloys
    • Materials Chemistry

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