Electromotive force of gas concentration cell using alumina-rich nonstoichiometric magnesium aluminate spinel as the solid electrolyte

Abstract

The following gas concentration cell, (-,work.), Pt(P′O2, P′H2)Iota;Mg0.8Al2O 4-δΙPt(P″O2, P″H2), (ref.,+) was constructed and the electromotive force was measured in the temperature range from 1373 to 1673 K. When the oxygen partial pressure on both electrodes was kept at a constant value, hydrogen partial pressure difference on the electrodes did not give any significant electromotive force at the experimental temperatures. When the hydrogen partial pressures were kept at a constant value on both electrodes, the electromotive force dependent on the difference of the oxygen partial pressure on the electrodes was obtained. The electromotive force was in agreement with the theoretical value calculated on assumption that the activity of magnesia was kept constant throughout in the electrolyte and that the transport number of cation was unity. © 2008 The Japan Institute of Metals.