Structural and Transport Properties of La Tungstate and Its Composite with Nickel (II) and Copper (II) Oxides Full article
Journal |
Chimica Techno Acta
, E-ISSN: 2411-1414 |
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Output data | Year: 2025, Volume: 12, Number: 2, Article number : 12205, Pages count : 13 DOI: 10.15826/chimtech.2025.12.2.05 | ||||||
Tags | Radiation thermal sintering; Lanthanide tungstates; Composites; Hydrogen separation membranes; Oxygen transport; Isotope exchange of oxygen | ||||||
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Affiliations |
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Funding (2)
1 | Russian Science Foundation | 23-73-00045 |
2 | Ministry of Science and Higher Education of the Russian Federation | FWUR-2024-0038 |
Abstract:
La tungstates possessing a high protonic conductivity (~10–4 S/cm at 600 °C) are state-of-the-art materials for hydrogen separation membranes. A promising approach in design of new materials for this application is creation of triple-conductive materials on their basis. The current work aims at studying structural, textural and transport properties of La27W5O55.5–δ and the composite of La27W5O55.5–δ with NiO and CuO obtained via the mechanical activation and sintered either in a furnace or by radiation thermal sintering using electron beam. The oxide material obtained is distorted double fluorite, while the composites consist of LaNi0.8W0.2O3–δ, NiO and CuO phases. As compared to the oxide sintered in furnace, the electron beam sintered La27W5O55.5–δ demonstrates a lower occupancy of 24f sites by W, higher La:W ratio and larger grain size. Extended defects including grain boundaries are observed in TEM images. La27W5O55.5–δ possesses moderate oxygen transport properties (oxygen tracer diffusion coefficient ~10–10 cm2/s at 800 °C). Thermogravimetric analysis demonstrates that the materials exhibit the hydration behavior typical of proton conductors. The oxygen mobility is demonstrated to decline in the composites, which can be caused by a lower oxygen mobility of the LaNi0.8W0.2O3–δ phase compared to the La27W5O55.5–δ one and the diffusion hindered by nanoparticles of NiO and CuO. Reduction followed by reoxidation of the composites leads to increasing oxygen diffusivity, which can be related to partial unblocking of fast diffusion pathways.
Cite:
Eremeev N.
, Bespalko Y.
, Sadovskaya E.
, Krieger T.
, Cherepanova S.
, Suprun E.
, Ishchenko A.
, Mikhailenko M.
, Korobeynikov M.
, Sadykov V.
Structural and Transport Properties of La Tungstate and Its Composite with Nickel (II) and Copper (II) Oxides
Chimica Techno Acta. 2025. V.12. N2. 12205 :1-13. DOI: 10.15826/chimtech.2025.12.2.05
Structural and Transport Properties of La Tungstate and Its Composite with Nickel (II) and Copper (II) Oxides
Chimica Techno Acta. 2025. V.12. N2. 12205 :1-13. DOI: 10.15826/chimtech.2025.12.2.05
Dates:
Submitted: | Dec 11, 2024 |
Accepted: | Dec 30, 2024 |
Published online: | Jan 16, 2025 |
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