Repozytorium publikacji - Politechnika Gdańska

Iron doped strontium titanates (SrTi1-xFexO3-δ) are an interesting mixed ionic-electronic conductor model used to study basic oxygen reduction/oxidation reactions. In this work, we performed an impedance spectroscopy study on symmetrical porous SrTi0.30Fe0.70O3-δ (STF70) electrodes on a ceriabased electrolyte. The sample was measured in varying oxygen concentration: from 0.3% to 100% in 800 °C - 500 °C temperature range. Low polarisation resistance (e.g. <125 mΩ cm2 at 600 °C in the air) values were obtained, showing an overall high performance of the STF70 electrode. Impedance data analysis was assisted by the distribution of relaxation times method, which allowed an equivalent electrical circuit to be proposed comprising of two resistance/constant phase element sub-circuits connected in series. The medium frequency contribution, with a characteristic frequency of ~2000 Hz at 800 °C in air, originates most probably from possible surface diffusion followed by charge transfer reaction limitation, whereas the lower frequency contribution (characteristic frequency <10 Hz) is due to gas-phase diffusion.

Autorzy

• dr inż. Aleksander Mroziński link otwiera się w nowej karcie ,
• dr hab. inż. Sebastian Molin link otwiera się w nowej karcie ,
• prof. dr hab. inż. Piotr Jasiński link otwiera się w nowej karcie