Effect of Eu dopant concentration in SrCe1 − xEuxO3 − δ on ambipolar conductivity

The europium dopant concentration in strontium cerate was studied to achieve maximum hydrogen permeation. In order to determine high ambipolar conductivity, total conductivity and open circuit potential measurements were performed. Among the three different compositions of Eu-doped SrCe1 − xEuxO3 − δ (x = 0.1, 0.15 and 0.2) studied, SrCe0.9Eu0.1O3 − δ showed highest total conductivity between 600 °C and 900 °C. However, transference number measurements showed increasing electronic conductivity with increasing dopant concentration and a stronger temperature dependence for electronic conduction. Therefore, the highest ambipolar conductivity was obtained over the compositional range from SrCe0.85Eu0.15O3 − δ to SrCe0.8Eu0.2O3 − δ depending on temperature. Finally, the hydrogen permeation flux was calculated based on the ambipolar conductivity and compared with experimental results.