Robust Ruddlesden‐Popper phase Sr3Fe1.3Mo0.5Ni0.2O7‐δ decorated with in‐situ exsolved Ni nanoparticles as an efficient anode for hydrocarbon fueled solid oxide fuel cells

Abstract

Abstract A highly efficient Ruddlesden‐Popper structure anode material with a formula of Sr3Fe1.3Mo0.5Ni0.2O7‐δ (RP‐SFMN) has been developed for hydrocarbon fueled solid oxide fuel cells (HF‐SOFC) application. It is demonstrated that a nanostructured RP‐SFMN anode decorated with in‐situ exsolved Ni nanoparticles (Ni@RP‐SFMN) has been successfully prepared by annealing the anode in reducing atmosphere similar to the operating conditions. The phase compositions, valence states, morphologies, and electrocatalytic activities of RP‐SFMN material have been characterized in detail. In addition, the in‐situ exsolution mechanism of the metallic Ni phase from the parent oxide is clearly explained by using density function theory calculation. The peak output power density at 800°C is significantly enhanced from 0.163 to 0.409 W/cm2 while the electrode polarization resistance is effectively lowered from 0.96 to 0.30 Ω cm2 by the substitution of B‐site Fe by Ni, which is attributed to the improved electrocatalytic activities induced by the in‐situ exsolved Ni nanocatalysts. Moreover, the single cell with RP‐SFMN anode exhibits good stability in 3% H2O humidified H2 and syngas for 110 and 60 h at 800°C, respectively. Our findings indicate that RP‐SFMN is a greatly promising anode candidate of HF‐SOFCs due to its good electrochemical performance and stability during the operation.

Keywords

• density function theory
• in‐situ exsolution
• nanostructured anode
• Ruddlesden‐Popper oxide
• solid oxide fuel cells