Tritium in Metals*

Lässer, R.

doi:10.1524/zpch.1985.143.143.023

Cited by 24 publications

(2 citation statements)

References 59 publications

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“…A direct comparison of the Van't Hoff plot of the Pd77Ag23-D and Pd77Ag23-H systems is reported in Figure S1 of the Supplementary Material. The lower enthalpy for deuteration than for hydrogenation was previously reported by Hara et al for Pd93Ag7 [37] (the enthalpy changed for the desorption of hydrogen and deuterium were evaluated to be 43.0 kJ/mol and 36.4 kJ/mol, respectively), Lässer for Pd90Ag10 [60], and it is well known for pure Pd(ΔHhydr = 40.2kJ/mol, ΔHdeut = 35.1kJ/mol) [61,62]. For an easier visualization of the values of hydrogenation/deuteration enthalpy, they are reported in Table 1, with a comparison of the literature data for the above-mentioned literature values.…”

Section: Enthalpy Of Deuterationmentioning

confidence: 50%

Promising Isotope Effect in Pd77Ag23 for Hydrogen Separation

et al. 2021

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Pd–Ag alloys are largely used as hydrogen separation membranes and, as a consequence, the Pd–Ag–H system has been intensively studied. On the contrary, fewer information is available for the Pd–Ag–D system; thus, the aim of this work is to improve the knowledge of the isotope effect on the commercial Pd77Ag23 alloy, especially for temperature above 200 °C. In particular, deuterium absorption measurements are carried out in the Pd77Ag23 alloy in the temperature range between 79 and 400 °C and in the pressure range between 10−2 and 16 bar. In this exploited pressure (p) and composition (c) range, above 300 °C the pc isotherms display the typical shape of materials where only a solid solution of deuterium is present while at lower temperatures these curves seem to be better described by the coexistence of a solid solution and a deuteride in a large composition range. The obtained results are compared and discussed with the ones previously measured with the lightest hydrogen isotope. Such a comparison shows that the Pd77Ag23 alloy exhibits a clear inverse isotope effect, as the equilibrium pressure of the Pd–Ag–D system is higher than in Pd–Ag–H by a factor of ≈2 and the solubility of deuterium is about one half of that of hydrogen. In addition, the absorption measurements were used to assess the deuteration enthalpy that below 300 °C is ΔHdeut = 31.9 ± 0.3 kJ/mol, while for temperatures higher than 300 °C, ΔHdeut increases to 43 ± 1 kJ/mol. Additionally, in this case a comparison with the lighter isotope is given and both deuteration enthalpy values result lower than those reported for hydrogenation. The results described in this paper are of practical interest for applications operating above 200 °C, such as membranes or packing column, in which Pd77Ag23 has to interact with a gas stream containing both hydrogen isotopes.

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Section: Enthalpy Of Deuterationmentioning

confidence: 50%

Promising Isotope Effect in Pd77Ag23 for Hydrogen Separation

et al. 2021

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“…Thermodynamic data obtained in the present study are compared in Table with those reported for Pd metal and different compositions of Pd–Ag and Pd–Cu alloys. ,,− A comparison of van’t Hoff plots is also made in Figure for same systems. It is evident that the Δ r H ° for the ternary alloy Pd 0.77 Ag 0.10 Cu 0.13 (37.2 ± 0.3 kJ/mol H 2 and 34.7 ± 0.2 kJ/mol D 2 ) is lower in magnitude compared to Pd and Pd–Ag alloys and higher in magnitude compared to Pd–Cu alloys, which is favorable for its application in room temperature SDGC application.…”

Section: Resultsmentioning

confidence: 98%

Hydrogen Isotope Effect on Thermodynamic and Kinetics of Hydrogen/Deuterium Absorption–Desorption in Pd_0.77Ag_0.10Cu_0.13Alloy

et al. 2015

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The hydrogen isotope effect on the thermodynamic and kinetics of hydrogen/deuterium absorption–desorption in a single-phase ternary alloy Pd0.77Ag0.10Cu0.13 having fcc crystal structure was investigated using a Sievert-type volumetric apparatus to explore its viability for use in room-temperature self-displacement gas chromatography (SDGC) for separation of hydrogen isotopes. Desorption pressure–composition isotherms (PCIs) were measured in the temperature range 313–393 K, and the kinetics of the absorption reaction were studied using isochoric measurements in the temperature range 303–333 K. PCIs revealed that P eq(D2) > P eq(H2) at all experimental temperatures. Thermodynamic analysis of the biphasic region (α + β) reveals that |Δr H°|(X=H) – |Δr H°|(X=D) > 0 and |Δr S°|(X=H) – |Δr S°|(X=D) < 0. Analysis of kinetic data suggests that diffusion of X through the hydride/deuteride is the rate-limiting step. The combination of structural, thermodynamic, and kinetic data suggests that the Pd0.77Ag0.10Cu0.13–H2/D2 system has favorable properties for use in room-temperature SDGC for hydrogen isotope separation.

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