CO2-induced in-situ surface reconfiguration of strontium cobaltite-based perovskite for accelerated oxygen reduction reaction

For solid oxide fuel cells, it is an effective strategy to enhance the oxygen reduction reaction activity of cathode through introducing active nanoparticles on electrode surface. In this study, we developed a novel cathode SrY 0.05 W 0.05 Co 0.9 O 3-δ and optimizing strategy of CO 2 -induced surface in-situ reconfiguration. The nanoscale SrCO 3 particles and the oxide nanoparticles could be produced after the treating atmosphere was switched from CO 2 to air. Both SrCO 3 nanoparticles and nano-oxides are beneficial to the oxygen reduction reaction kinetics of surface process and the area specific resistance of symmetric cell with SrY 0.05 W 0.05 Co 0.9 O 3-δ electrode decreased from 0.085 to 0.054 Ω cm 2 at 600 ℃. Although the nano-sized SrCO 3 was degraded in air over time, the oxide nanoparticles held a stable state for a long time and the resistance finally stabilized at ∼0.068 Ω cm 2 . However, for classic cathode Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3−δ , it possesses a strong interaction with CO 2 so that the produced large-sized BaCO 3 failed to transform into nanoparticles and totally decompose. Therefore, designing the suitable cathode and tailoring the interaction between CO 2 and electrode materials are significant to realize the CO 2 -induced surface in-situ reconfiguration.