Platinum and samaria-doped ceria (Pt-SDC) cermet cathode for low-temperature solid oxide fuel cells

Abstract

Platinum (Pt) and Samaria-doped ceria (SDC) as cermet cathodes were investigated to enhance oxygen reduction reaction (ORR) kinetics in low-temperature solid oxide fuel cells (SOFCs). Pt is widely known for its high catalytic activity, whereas SDC is one of the most promising oxide ionic conductors as an LT-SOFC electrolyte. To improve both the catalytic activity and oxygen ionic transportation, a co-sputtering technique was used to fabricate a composite cathode by adjusting the elemental composition of Pt and SDC. This technique demonstrated that the Pt-SDC cermet cathode can increase the electrochemical reaction sites and offer a percolated pathway for rapid electron-ion conduction within the cermet structure. The electrochemical analysis results also revealed that the fuel cells coated with Pt-SDC cermet cathodes outperformed the pure Pt-coated fuel cells in terms of peak power density. The electrochemical impedance spectroscopy analysis indicated that the improved ORR kinetics of Pt-SDC cermet cathodes were the main reason for the improved fuel cell performance by catalyzing both electron and oxygen ion conduction.