First-principles study of a new structure and oxidation mechanism of Pt₃Zr

Abstract

Zirconia (ZrO 2 )-metal interfaces are interesting for solid oxide fuel cells. Although the oxidation of Pt 3 Zr provides a new route for the formation of ZrO 2 -Pt interfaces, the crystal structure of Pt 3 Zr remains controversial and the oxidation mechanism of Pt 3 Zr is unclear. To solve these problems, we use firstprinciples calculations to explore the crystal structure of Pt 3 Zr. We demonstrate a stable structure of Pt 3 Zr based on phonon dispersion. Importantly, two new Pt 3 Zr structures, Ti 3 Pt-type (Pm 3m) and Fe 3 Al-type (Fm 3m), are predicted. To study the oxidation mechanism, two possible doped models are considered. The calculated results show that the O atom prefers to occupy the tetrahedral interstitial site (TI) in comparison to the octahedral interstitial site (OI). We find that the oxidizing capacity of the Fe 3 Al-type cubic structure is stronger than that of other structures. In particular, we predict that Pt 3 Zr exhibits better oxidation capacity in comparison to other metals because of the strong localized hybridization between Zr and O.

Ab initio study of structural, electronic, thermo-elastic and optical properties of Pt3Zr intermetallic compound

“…However, in the above range the Fermi level from 0 to 9 eV at the anti-bonding states is dominated by the hybridization of Pt-5d and Zr-4d states. This result agree very well with those obtained by Pan et al [24,26,27] The contribution of Zr-s, p and Pts, p in the PDOS of L1 2 -Pt 3 Zr is negligible. Furthermore, the main bonding peak is situated at −3.66 eV and the main antibonding peak, coming from a strong hybridization between Ptd and Zr-d states, is situated in the energy range 0.42-1.1 eV.…”

“…We find that the ∆H f of the Pt 3 Zr compound in the D0 24 phase is lower than that in the L1 2 phase, which indicates that Pt 3 Zr in the hexagonal structure is more stable than that in the cubic structure. [36] 4.051 other [5,[24][25][26][27]38,39] 4 [5] 5.653 9.347 [5] other [25,26,29] 5.729 a , 5.742 a 9.364 a , 9.398 a 226 a −1.108 a a Data from the PBE-GGA method. b Data from the LDA method.…”

“…[25] First principles calculations have been im-plemented with the CASTEP code by Pan et al to study a new structure and oxidation mechanism of the Pt 3 Zr compound. [26] Interfacial stability, electronic structure and bond characteristics of Pt 3 Zr (111)/Pt (111) interfaces have been investigated by Pan et al using ab-initio calculations. [27] Using high resolution x-ray photoelectron spectroscopy, temperature programmed desorption, scanning tunneling microscopy and density functional theory, Li el al.…”

Novel and Optimized Techniques for Storage and Transportation of Hydrogen: Perspectives and Challenges

“…They are energy efficient up to 22% and 45% respectively. It demonstrates that hydrogen can be used as an alternative energy resource in the upcoming time [6][7]. There are (Chemical, Physical and Electro-chemical) storage methods of hydrogen which can store it in a solid form.…”