TY - JOUR
T1 - Synthesis, structure, chemical stability, and electrical properties of Nb-, Zr-, and Nb-codoped BaCeO3 perovskites
AU - Bhella, Surinderjit Singh
AU - Fürstenhaupt, Tobias
AU - Paul, Reginald
AU - Thangadurai, Venkataraman
PY - 2011/7/18
Y1 - 2011/7/18
N2 - We report the effect of donor-doped perovskite-type BaCeO3 on the chemical stability in CO2 and boiling H2O and electrical transport properties in various gas atmospheres that include ambient air, N2, H2, and wet and dry H2. Formation of perovskite-like BaCe1-xNbxO3±δ and BaCe0.9-xZrxNb0.1O3±δ (x = 0.1; 0.2) was confirmed using powder X-ray diffraction (XRD) and electron diffraction (ED). The lattice constant was found to decrease with increasing Nb in BaCe1-xNbxO3±δ, which is consistent with Shannon's ionic radius trend. Like BaCeO3, BaCe 1-xNbxO3±δ was found to be chemically unstable in 50% CO2 at 700 °C, while Zr doping for Ce improves the structural stability of BaCe1-xNbxO 3±δ. AC impedance spectroscopy was used to estimate electrical conductivity, and it was found to vary with the atmospheric conditions and showed mixed ionic and electronic conduction in H 2-containing atmosphere. Arrhenius-like behavior was observed for BaCe0.9-xZrxNb0.1O3±δ at 400-700 °C, while Zr-free BaCe1-xNbxO 3±δ exhibits non-Arrhenius behavior at the same temperature range. Among the perovskite-type oxides investigated in the present work, BaCe0.8Zr0.1Nb0.1O 3±δ showed the highest bulk electrical conductivity of 1.3 × 10-3 S cm-1 in wet H2 at 500 °C, which is comparable to CO2 and H2O unstable high-temperature Y-doped BaCeO3 proton conductors.
AB - We report the effect of donor-doped perovskite-type BaCeO3 on the chemical stability in CO2 and boiling H2O and electrical transport properties in various gas atmospheres that include ambient air, N2, H2, and wet and dry H2. Formation of perovskite-like BaCe1-xNbxO3±δ and BaCe0.9-xZrxNb0.1O3±δ (x = 0.1; 0.2) was confirmed using powder X-ray diffraction (XRD) and electron diffraction (ED). The lattice constant was found to decrease with increasing Nb in BaCe1-xNbxO3±δ, which is consistent with Shannon's ionic radius trend. Like BaCeO3, BaCe 1-xNbxO3±δ was found to be chemically unstable in 50% CO2 at 700 °C, while Zr doping for Ce improves the structural stability of BaCe1-xNbxO 3±δ. AC impedance spectroscopy was used to estimate electrical conductivity, and it was found to vary with the atmospheric conditions and showed mixed ionic and electronic conduction in H 2-containing atmosphere. Arrhenius-like behavior was observed for BaCe0.9-xZrxNb0.1O3±δ at 400-700 °C, while Zr-free BaCe1-xNbxO 3±δ exhibits non-Arrhenius behavior at the same temperature range. Among the perovskite-type oxides investigated in the present work, BaCe0.8Zr0.1Nb0.1O 3±δ showed the highest bulk electrical conductivity of 1.3 × 10-3 S cm-1 in wet H2 at 500 °C, which is comparable to CO2 and H2O unstable high-temperature Y-doped BaCeO3 proton conductors.
U2 - 10.1021/ic201008v
DO - 10.1021/ic201008v
M3 - Article
AN - SCOPUS:79960257302
SN - 0020-1669
VL - 50
SP - 6493
EP - 6499
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 14
ER -