Highly CO₂-tolerant cathode for intermediate-temperature solid oxide fuel cells: Samarium-doped ceria-protected SrCo_0.85Ta_0.15O_3-δ hybrid

(Graph Presented) Susceptibility to CO₂ is one of the major challenges for the long-term stability of the alkaline-earth-containing cathodes for intermediate-temperature solid oxide fuel cells. To alleviate the adverse effects from CO₂, we incorporated samarium-stabilized ceria (SDC) into a SrCo_0.85Ta_0.15O_3-δ (SCT15) cathode by either mechanical mixing or a wet impregnation method and evaluated their cathode performance stability in the presence of a gas mixture of 10% CO₂, 21% O₂, and 69% N₂. We observed that the CO₂ tolerance of the hybrid cathode outperforms the pure SCT15 cathode by over 5 times at 550°C. This significant enhancement is likely attributable to the low CO₂ adsorption and reactivity of the SDC protective layer, which are demonstrated through thermogravimetric analysis, energy-dispersive spectroscopy, and electrical conductivity study.