TY - JOUR

T1 - First-principle modeling of hydrogen site solubility and diffusion in disordered Ti-V-Cr alloys

AU - Баврина, Ольга Олеговна

AU - Шеляпина, Марина Германовна

AU - Klyukin, Konstantin

AU - Fruchart, Daniel

N1 - Funding Information: All the calculations were carried out using computational facilities provided by Resource Center «Computer Center of SPbU» ( http://cc.spbu.ru/en ). The authors are grateful for the sponsorship of the Russian Foundation for Basic Research (project # 16-32-00267 ).

PY - 2018/9/6

Y1 - 2018/9/6

N2 - Hydrogen diffusion and solubility in disordered alloys are of paramount importance to a variety of practical applications from hydrogen storage materials to separation membranes and protection against hydrogen embrittlement. By employing density functional theory calculations we unveil the atomic-level understanding of hydrogen diffusion in disordered Ti–V–Cr alloys used for hydrogen storage. Hydrogen distribution over interstitial sites of the bcc and fcc lattices of TiV 0.8Cr 1.2 has been simulated using a supercell approach. Taking into account both structural and energy factors we identify tetrahedral sites coordinated by three different metal atoms as the most favorable for hydrogen. The calculations carried out within the nudged elastic band method show that hydrogen diffusion between two tetrahedral site in fcc TiV 0.8.Cr 1.2H 5.25 occurs nearby an intermediate octahedral site with the activation barrier of 0.158 eV for the most probable diffusion pathway. An estimation of the hydrogen diffusion coefficient in fcc TiV 0.8.Cr 1.2H 5.25 at 294 K provides the value of 2.6 × 10 −11 m 2/s that is in fair agreement with experiment data. Despite the modeling was done for a hydride of a definite composition we anticipate that the present results could be extended to Ti–V–Cr hydrides with various compositions.

AB - Hydrogen diffusion and solubility in disordered alloys are of paramount importance to a variety of practical applications from hydrogen storage materials to separation membranes and protection against hydrogen embrittlement. By employing density functional theory calculations we unveil the atomic-level understanding of hydrogen diffusion in disordered Ti–V–Cr alloys used for hydrogen storage. Hydrogen distribution over interstitial sites of the bcc and fcc lattices of TiV 0.8Cr 1.2 has been simulated using a supercell approach. Taking into account both structural and energy factors we identify tetrahedral sites coordinated by three different metal atoms as the most favorable for hydrogen. The calculations carried out within the nudged elastic band method show that hydrogen diffusion between two tetrahedral site in fcc TiV 0.8.Cr 1.2H 5.25 occurs nearby an intermediate octahedral site with the activation barrier of 0.158 eV for the most probable diffusion pathway. An estimation of the hydrogen diffusion coefficient in fcc TiV 0.8.Cr 1.2H 5.25 at 294 K provides the value of 2.6 × 10 −11 m 2/s that is in fair agreement with experiment data. Despite the modeling was done for a hydride of a definite composition we anticipate that the present results could be extended to Ti–V–Cr hydrides with various compositions.

KW - DFT calculations

KW - Hydrogen diffusion

KW - Hydrogen site solubility

KW - Ti–V–Cr alloys

KW - MOBILITY

KW - HYDRIDES

KW - NUCLEAR-MAGNETIC-RESONANCE

KW - SOLID-SOLUTIONS

KW - RELAXATION

KW - DFT

KW - METALS

KW - Ti-V-Cr alloys

KW - DIFFRACTION

KW - SYSTEMS

KW - ABSORPTION

UR - http://www.scopus.com/inward/record.url?scp=85051395062&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/firstprinciple-modeling-hydrogen-site-solubility-diffusion-disordered-tivcr-alloys

U2 - 10.1016/j.ijhydene.2018.07.128

DO - 10.1016/j.ijhydene.2018.07.128

M3 - Article

VL - 43

SP - 17338

EP - 17345

JO - International Journal of Hydrogen Energy

JF - International Journal of Hydrogen Energy

SN - 0360-3199

IS - 36

ER -