Permeation and diffusion of hydrogen in vanadium using deoxidation and glow-discharge surface cleaning techniques

Fujimura, Naoya; Asano, Keisuke; Nakamura, Ryusuke; Iijima, Yoshiaki

doi:10.1016/j.memsci.2020.118522

Cited by 7 publications

(7 citation statements)

References 35 publications

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“…XPS can cover up to 10 nm compared to a depth of XRD penetration up to a few micrometers. The absence of oxides is better for hydrogen permeation . Nevertheless, hydrogen permeation was possible beneath the thin oxide layers.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, another factor was impacting the change in hydrogen permeability. Vanadium oxide layers that can trap hydrogen 9 might affect the hydride removal relevant to the permeability recovery. By considering that the palladium-coated alloy is oxide free, catalytic dissociation of hydrogen can be active in the remaining spots in vanadium as well as in palladium.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the remaining hydrogen and hydrides can affect the ternary V–Ni–H system as well as the hydrogen permeation through the V–Ni alloy. Furthermore, the vanadium oxide layers potentially trap the hydrogen atoms, 9 leading to the accumulation of hydrogen inside the alloy unlike the palladium-coated alloy. As a result, when the hydrogen permeation was repeated after the thermal treatments, the hydrogen permeability values varied even though the pressure of gases and the temperature were identical.…”

Section: Resultsmentioning

confidence: 99%

“…Vanadium oxides will form instantly at the surface of vanadium when vanadium meets oxygen. Vanadium oxides could have a significant influence on hydrogen permeation in a vanadium membrane . In general, a palladium coating was applied or vacuum was utilized to reduce the contact between the alloy and other gases to address the oxidation of vanadium .…”

Section: Introductionmentioning

confidence: 99%

“…Vanadium oxides could have a significant influence on hydrogen permeation in a vanadium membrane. 9 In general, a palladium coating was applied or vacuum was utilized to reduce the contact between the alloy and other gases to address the oxidation of vanadium. 10 However, palladium coatings have an issue of intermetallic diffusion with vanadium at high temperatures and the catalytic behavior of palladium decreases with the performance of the alloy.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Gas for Thermal Treatment on Hydrogen Permeation in V–Ni Alloy Membranes

2023

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Hydrogen separation is an important step for the utilization of hydrogen energy. Metallic alloys, such as vanadium−nickel, are potential hydrogen separation materials. Due to the strong propensity of vanadium to form oxides and hydrides, vanadium alloy has a lower hydrogen permeability, and it is difficult to maintain the permeability over time. Therefore, special preparation processes such as Pd coating have been suggested for hydrogen separation vanadium-based membranes. However, aside from the prohibitive price of palladium, the interdiffusion of palladium and vanadium makes the coated membrane inviable to be used at a high temperature. Thermal treatment with inert gas was investigated in this study to assess the applicability of the vanadium alloy without palladium coating for hydrogen separation and clarify the mechanism behind the thermal treatment. Argon is inert with vanadium and displayed permeability recovery after 43 h thermal treatment, but the permeability declined under certain conditions. In contrast, nitrogen is known to interact with vanadium and the hydrogen permeability was maintained at a level lower than the test with argon. Given that nitrogen can compete with hydrogen for the active sites on vanadium, nitrogen might hinder hydrogen adsorption and hydride formation, whereas argon reduced the partial pressure of hydrogen during the thermal treatment, enhancing the driving force of hydrogen desorption. In the X-ray diffraction spectrum, vanadium hydrides and oxides were confirmed after hydrogen permeation and thermal treatment. In the X-ray photoelectron spectroscopy data, oxygen was a dominant element due to vanadium oxides and adsorbed nitrogen was also observed. According to binding energy shifts of nitrogen, nitrogen used for thermal treatment might substitute or compete for active sites with adsorbed nitrogen and hydrogen, existing in vanadium lattice. Although thermal treatment can be used to recover hydrogen permeability, the alloy cannot be recovered as hydrogen-free. However, results demonstrate the potential of thermal treatment to complement an uncoated vanadium alloy for a hydrogen separation membrane.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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