Key trends in the proton conductivity of Ln6−MoO12− (Ln = La, Nd, Sm, Gd -Yb; x = 0, 0.5, 0.6, 0.7, 1) rare-earth molybdates
| Autor: | L. G. Shcherbakova, Alexander N. Shchegolikhin, A. V. Shlyakhtina, Nikolay V. Lyskov, O.K. Karyagina, I. V. Kolbanev |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Ionic radius Proton Structural type Renewable Energy Sustainability and the Environment Rare earth Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology Conductivity 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Oxygen 0104 chemical sciences Crystallography Fuel Technology chemistry Molybdenum Lanthanum 0210 nano-technology |
| Zdroj: | International Journal of Hydrogen Energy. 46:16989-16998 |
| ISSN: | 0360-3199 |
| Popis: | We have studied the structure and proton conductivity of rhombohedral La6−xMoO12−δ (x = 0.5, 0.6, 0.7, 1) lanthanum molybdates prepared via mechanical activation of lanthanum and molybdenum oxides, followed by thermal annealing at 1650 °C. The La6−xMoO12−δ (x = 0.5, 0.6) materials were phase-pure and had a complex rhombohedral structure (R1). An increase in the molybdenum concentration leads to a decrease in the degree of rhombohedral distortion and proton conductivity in the La6−xMoO12−δ (x = 0.5, 0.6, 0.7, 1) series. The proton conductivity at the optimal composition La6−xMoO12−δ (x = 0.5) is ~4.0 × 10−5 S/cm at 500 °C in wet air. A comparative analysis shows that, in the Ln6−xMoO12−δ (Ln = La, Nd, Sm, Gd, Dy, Ho, Er, Tm, Yb; x = 0–1) series, proton conductivity decreases with the Ln ionic radii decreasing regardless of the structural type. Because of this, the high proton conductivity is demostrated by the stable La6−xMoO12−δ (x = 0.5, 0.6) materials, with an inherently deficient oxygen sublattice, which crystallize in a large-volume, complex rhombohedral cell (R1). |
| Databáze: | OpenAIRE |
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