A Highly Efficient and Robust Perovskite Anode with Iron-Palladium Co-exsolutions for Intermediate-Temperature...

The low performance and insufficient catalytic activity of perovskite anodes hinder their further application in intermediate-temperature solid-oxide fuel cells (IT-SOFCs). A novel La_0.8 Sr_0.2 Fe_0.9 Nb_0.1 Pd_0.04 O_3-δ (LSFNP) anode material has been developed with Fe-Pd co-exsolutions for IT-SOFCs. Fe⁰ and Pd⁰ metallic nanoparticles are confirmed to exsolve on the surface of the perovskite anode during operation under a hydrogen atmosphere. The introduced Pd exsolutions promote the charge-transfer process slightly and the H₂ -adsorption ability of the La_0.8 Sr_0.2 Fe_0.9 Nb_0.1 O_3-δ (LSFN) parent anode significantly, as metallic Pd is a conductor with excellent catalytic activity and an absorber of hydrogen that can absorb a large amount of H₂ by forming unstable chemical bonds. A single cell with the LSFNP anode exhibits high output performance (maximum power density of 287.6 mW cm^-2 at T=800 °C by using humidified H₂ as the fuel), excellent redox stability, and considerable coking and sulfur tolerances. After the introduction of Pd exsolutions, the increase in the electrochemical performance is more significant under low H₂ concentrations and at low temperatures with a maximum power density ratio of the LSFNP anode cell/LSFN anode cell reaching 18 under 5 % H₂ /argon at T=650 °C. Pd-decorated LSFNP is a high-performance, redox-stable, coking-tolerant, and sulfur-tolerant anode material for IT-SOFCs, making Pd exsolution a reliable nanodecoration strategy to improve the low kinetics of perovskite anodes.