In Situ Growth of Ru/RuO2 Nanoparticle-Modified (PrBa)0.95Mn1.9Ru0.1O5+δ as a High-Performance Electrode for Symmetrical Solid Oxide Fuel Cells

(PrBa)0.95Mn1.9Ru0.1O5+δ (PBMRu) layered double perovskite is turned into a highly active electrode for symmetrical solid oxide fuel cells (SSOFCs) by introducing Ru/RuO2 catalysts through in situ growth, which demonstrates excellent electrochemical properties as both oxygen and fuel electrodes. The catalytically active Ru nanoparticles exsolve during the reducing step of the preparation process and can be oxidized to nanosized RuO2 catalysts when operating as an oxygen electrode. Optimized by substitutional Ru and in situ nanosized Ru/RuO2 catalysts, the favorable electrical conductivities of 14.89 and 146.81 S cm–1 are possessed for PBMRu in 5% H2/N2 and air at 750 °C, which are much higher than 7.83 and 90.76 S cm–1 of (PrBa)0.95Mn2O5+δ (PBM). With Ru and RuO2 nanoparticles on the two sides of the cell, respectively, symmetrical single-cell PBMRu–SSZ|SSZ|PBMRu–SSZ (SSZ = Sc2O3-stabilized ZrO2) exhibits an outstanding output performance of 0.92 W cm–2 at 750 °C. All of these findings suggest that in situ Ru/RuO2 nanocatalyst-modified PBMRu would be a promising candidate for an electrode in high-performance SSOFC applications.