TY - JOUR
T1 - Studies of rubidium selenate with secondary phase of RbOH under humidified reducing atmosphere
AU - Beyribey, Berceste
AU - Hallinder, Jonathan
AU - Poulsen, Finn Willy
AU - Bonanos, Nikolaos
AU - Mogensen, Mogens Bjerg
PY - 2012
Y1 - 2012
N2 - The high temperature properties of Rb2SeO4 have been studied by calorimetry, impedance spectroscopy and X-ray powder diffraction. As synthesized, Rb2SeO4 includes a second phase of Rb2SeO3, which can be eliminated upon heating the compound. As expected, no conductivity is observed in dry (pH2O < 0.001 bar) air. By changing to humidified (pH2O = 0.1 bar) air at 176 deg. C, the conductivity increases sharply from 8.6·10-8 to 1.7·10-6 S cm-1. Under humidified (pH2O = 0.1 bar) reducing atmosphere (9%H2 in N2), the conductivity increases to 2.0·10-4 S cm-1 at 317 C. Degradation of Rb2SeO3 and Rb2SeO4 to form RbOH, which is known as a proton conductor, are thought to be responsible for the observed conductivity in humidified atmospheres. Our observations may explain the conductivity rise in other solid acid electrolytes, including sulfate and selenate groups, around their decomposition temperatures, in humidified atmospheres.
2012 Elsevier B.V. All rights reserved.
AB - The high temperature properties of Rb2SeO4 have been studied by calorimetry, impedance spectroscopy and X-ray powder diffraction. As synthesized, Rb2SeO4 includes a second phase of Rb2SeO3, which can be eliminated upon heating the compound. As expected, no conductivity is observed in dry (pH2O < 0.001 bar) air. By changing to humidified (pH2O = 0.1 bar) air at 176 deg. C, the conductivity increases sharply from 8.6·10-8 to 1.7·10-6 S cm-1. Under humidified (pH2O = 0.1 bar) reducing atmosphere (9%H2 in N2), the conductivity increases to 2.0·10-4 S cm-1 at 317 C. Degradation of Rb2SeO3 and Rb2SeO4 to form RbOH, which is known as a proton conductor, are thought to be responsible for the observed conductivity in humidified atmospheres. Our observations may explain the conductivity rise in other solid acid electrolytes, including sulfate and selenate groups, around their decomposition temperatures, in humidified atmospheres.
2012 Elsevier B.V. All rights reserved.
KW - Rubidium selenate
KW - High temperature X-ray diffraction
KW - Impedance spectroscopy
KW - Thermal analysis
U2 - 10.1016/j.jallcom.2012.08.034
DO - 10.1016/j.jallcom.2012.08.034
M3 - Journal article
SN - 0925-8388
VL - 545
SP - 85
EP - 89
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -