Encapsulation of Metal Catalysts for Stable Solid Oxide Fuel Cell Cathodes

Metal catalysts have been employed as cathodes for solid oxide fuel cells to facilitate the surface exchange rate in the intermediate temperature range (600–800 °C). However, incorporated metal catalysts easily agglomerate, resulting in the loss of the reaction sites; thus, the electrochemical performance rapidly deteriorates over time. To hinder the agglomeration of metal catalysts while maintaining the catalytic activity, we encapsulated metal catalysts with nano-particulated perovskite materials using an infiltration technique. The encapsulation of Ag nanoparticles with nano-particulated Sm_0.5Sr_0.5CoO_3-δ (SSC) successfully prevented the agglomeration of Ag nanoparticles, maintaining the initial polarization resistance for 200 h at 650 °C, while the polarization resistance of the SSC electrodes with the Ag nanoparticles increased by ~ 190% after 200 h at 650 °C because of the thermal agglomeration of Ag nanoparticles.