High‐Performance Electrode for Medium‐Temperature Operating Solid Oxide Fuel Cells Polarization Property of Ceria‐Based Anode with Highly Dispersed Ruthenium Catalysts in Gas

TLDR: In this paper, the polarization properties of catalyzed anode for medium-temperature operating solid oxide fuel cells were examined in a synthetic gas containing H{sub 2, CO{ sub 2, and H{ sub 1}O. The overpotential was greatly decreased by loading only a small amount of Ru microcrystals onto the mixed conducting oxide, samaria-doped ceria (SDC), anode layer in both synthetic gas and wet hydrogen atmospheres.

Abstract: Polarization properties of catalyzed anode, which the authors developed for medium-temperature operating solid oxide fuel cells, were examined in a synthetic gas containing H{sub 2}, CO{sub 2}, and H{sub 2}O. The overpotential was greatly decreased by loading only a small amount of Ru microcrystals onto the mixed conducting oxide, samaria-doped ceria (SDC), anode layer in both synthetic gas and wet hydrogen atmospheres. It was found that the Ru-SDC anode exhibited the highest electrocatalytic activities at an optimum oxygen partial pressure in the fuel gas due to high conductivities of both electrons and oxide ions in the SDC. The maximum current density on the Ru-SDC anode exceeded 1 A/Cm{sup 2} at all the operating temperatures between 800 and 1,000 C at the potential of {minus}0.9 V vs. air reference electrode, when 0.1 mg/cm{sup 2} of Ru microcatalysts were loaded on the SDC surface and the appropriate fuel gas was used.