First-principles study of hydrogen permeation in palladium-gold alloys

Xu, Shaojie; Sood, Parveen; Liu, Meilin; Bongiorno, Angelo

doi:10.1063/1.3656739

Cited by 7 publications

(7 citation statements)

References 22 publications

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“…The significant variation in grain size in the dehydrated samples (Figures 6, 7 and 9d) and the inclusions of olivine and enstatite in coarse-grained olivine (Figure 7) strongly demonstrate that significant grain growth should have occurred after the nucleation. The CPOs of fine-grained olivine in our study (Figures 8 and S3) are consistent with those of prograde olivine and enstatite reported in Padrón-Navarta et al ( 2015 Padrón-Navarta et al (2015), the sealed capsules were made of Au that is not permeable for H (Xu et al, 2011). Hence, the antigorite was dehydrated under an undrained condition.…”

Section: Olivine Cpo Evolution During Antigorite Hydrostatic Dehydrationsupporting

confidence: 91%

“…In the experiments performed by Padrón‐Navarta et al. (2015), the sealed capsules were made of Au that is not permeable for H (Xu et al., 2011). Hence, the antigorite was dehydrated under an undrained condition.…”

Section: Discussionmentioning

confidence: 99%

“…In contrast, the coarse-grained olivine developed a clear [001] point maximum parallel to the pre-existing lineation, that is, [001] ol //[010] atg , which cannot be explained by the topotactic growth of [100] ol //[001] atg . In the experiments performed by Padrón-Navarta et al (2015), the sealed capsules were made of Au that is not permeable for H (Xu et al, 2011). Hence, the antigorite was dehydrated under an undrained condition.…”

Section: Olivine Cpo Evolution During Antigorite Hydrostatic Dehydrationmentioning

confidence: 99%

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Hydrostatic Dehydration Fabrics of Antigorite at High Pressure and High Temperature: Implications for Trench Parallel Seismic Anisotropy at Convergent Plate Boundaries

Liu

Zhang

et al. 2021

JGR Solid Earth

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Antigorite dehydration is well known as a key process at convergent boundaries for the genesis of mantle wedge partial melting and intermediate‐depth earthquakes. However, the crystallographic preferred orientations (CPOs) of prograde minerals from antigorite dehydration and their effects on the seismic anisotropy of subducting slabs remain ambiguous and controversial. Here we report antigorite dehydration experiments on a foliated serpentinized peridotite at pressures of 0.3–6 GPa and temperatures of 700–900°C. Our results show that olivine CPO evolves from a fiber‐[100] type in fine grains to a type‐C like in coarse grains. We propose that the fiber‐[100] olivine CPO is developed by topotactic growth during incipient hydrostatic dehydration, while the orthorhombic type‐C like olivine CPO is developed by anisotropic growth resulting from an anisotropic fluid flow during later dehydration. The type‐C like olivine CPO in the antigorite‐rich layers after antigorite dehydration could contribute to the trench parallel fast shear wave seismic anisotropy at convergent plate boundaries.

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Section: Olivine Cpo Evolution During Antigorite Hydrostatic Dehydrationsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Olivine Cpo Evolution During Antigorite Hydrostatic Dehydrationmentioning

confidence: 99%

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Hydrostatic Dehydration Fabrics of Antigorite at High Pressure and High Temperature: Implications for Trench Parallel Seismic Anisotropy at Convergent Plate Boundaries

Liu

Zhang

et al. 2021

JGR Solid Earth

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“…(iii) For a Pd-Au alloy, the theory was used to scrutinize the arrangement of atoms [20][21][22][23][24]. In addition, DFT indicates that hydrogen absorption becomes less favorable with increasing Au content [25,26]. Detailed tables with the binding energies and frequencies of vibrations of H atoms for H absorption on sites with different arrangements of Pd and Au atoms are, however, lacking there, and accordingly the use of the data reported was not straightforward in our context.…”

Section: Introductionmentioning

confidence: 99%

Suppression of hysteresis in absorption of hydrogen by a Pd-Au alloy

Mamatkulov

Zhdanov

2020

Phys. Rev. E

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Hydrogen absorption by Pd exhibits hysteresis loops (provided the temperature is not too high) and represents one of the classical examples of first-order phase transitions in metals. Experiments indicate that addition of even a small amount of Au is able to suppress hysteresis. From this perspective, we analyze the energetics of hydrogen in a Pd-Au alloy by using extensive density-functional-theory (DFT) calculations. The dependence of the hydrogen binding energy on the number (n) of Au atoms forming an adsorption site is found to be appreciably nonlinear. With the DFT input for statistical calculations, we reproduce special features of the hydrogen absorption isotherms and explain the rapid decrease of the corresponding critical temperature with increasing Au fraction. The key factor here is that the phase transition is related primarily to absorption in sites formed only by Pd. With increasing Au amount, the fraction of such sites rapidly decreases, the distance between H atoms located there becomes on average larger, the interaction between them becomes weaker, and accordingly the driving force for the phase transition decreases. It is of interest that all these effects can be illustrated by taking only the configurations with n 2 into account. This means that in the context under consideration the fine details of the dependence of the hydrogen binding energy on n are in fact not too important.

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“…2 is 0.54 eV (Fig 1(a)). In the bulk of Pd, hydrogen finds stable configurations in correspondence of the octahedral (O h ) and tetrahedral (T d ) sites of the fcc lattice [22]. Our calculations give, in particular, energies of -0.02 eV and 0 eV for a hydrogen species in Pd at the O h and T d sites, respectively.…”

Section: Resultsmentioning

confidence: 88%

Protons Crossing Triple Phase Boundaries based on Pd and Barium Zirconate: A Density Functional Theory Study

Malagoli

Bongiorno

2013

MRS Proc.

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Density functional theory calculations are used to address the energetics of protons crossing "triple phase boundaries" based on Pd and barium zirconate. Our calculations show that the proton transfer reaction at these triple phase boundaries is controlled by the terminal layer of the electrolyte in contact with the metallic catalyst and gas phase. Hydrogen spilling onto the electrolyte surface is energetically favored at peripherical sites of the metal-electrolyte interface, and proton incorporation into the sub-surface region of the electrolyte involves energies of the order of 1 eV. At the triple phase boundary, the energy cost associated with the proton transfer reaction is controlled by both the nature of chemical contact and the Schottky barrier at the metal-electrolyte interface.

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First-principles study of hydrogen permeation in palladium-gold alloys

Cited by 7 publications

References 22 publications

Hydrostatic Dehydration Fabrics of Antigorite at High Pressure and High Temperature: Implications for Trench Parallel Seismic Anisotropy at Convergent Plate Boundaries

Hydrostatic Dehydration Fabrics of Antigorite at High Pressure and High Temperature: Implications for Trench Parallel Seismic Anisotropy at Convergent Plate Boundaries

Suppression of hysteresis in absorption of hydrogen by a Pd-Au alloy

Protons Crossing Triple Phase Boundaries based on Pd and Barium Zirconate: A Density Functional Theory Study

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