Study of high active and redox-stable La0.9Ca0.1Fe0.9Nb0.1O3-δ/Sm0.1Ce0.9O2−δ composite ceramic electrode for solid oxide reversible cells.

In this paper, the catalytic activity of a ferrite/ceria composite ceramic fuel electrode La 0.9 Ca 0.1 Fe 0.9 Nb 0.1 O 3-δ /Sm 0.1 Ce 0.9 O 2−δ (LCFNb/SDC) for solid oxide reversible cells (SOCs) is studied by using YSZ (Zr 0.84 Y 0.16 O 2-δ ) and LSM/YSZ (LSM(La 0.8 Sr 0.2 MnO 3-δ )) as electrolyte and oxygen electrode, respectively. The asymmetrical LCFNb/SDC|YSZ|LSM/YSZ cells are prepared and evaluated electrochemically by using DC (cyclic voltammetry (CV) and galvanostatic) and AC impedance techniques in 50% CO: 50% CO 2 at the fuel electrode compartment. XRD results indicate LCFNb in the composite fuel electrode is stable in CO and CO 2 at high temperature and the LCFNb/SDC membane fuel electrode prepared by infiltration method presents high performance towards CO 2 reduction and CO oxidation. The polarization resistance under open circuit in a 50% CO: 50% CO 2 gas composition at 800 °C is 0.97 Ω cm 2 . However, both the CV and polarized impedance data show that the cell performance is higher for the electrolysis of CO 2 than for the oxidation of CO. The polarization resistance in 50% CO: 50% CO 2 at 1.4 V at 800 °C is 0.39 Ω cm 2 . Notably, the cell shows a highly stable activity towards CO 2 electrolysis at different applied voltages at the temperature of 800 °C. [ABSTRACT FROM AUTHOR]