Enhancing Stability and Catalytic Activity by in Situ Exsolution for High-Performance Direct Hydrocarbon Solid Oxide Fuel Cell Anodes

La0.2Sr0.8TiO3+δ (LST)-based perovskite oxide is considered as a promising anode material for solid oxide fuel cells (SOFCs) because of its strong phase stability. Herein, this work develops a strategy to enhance its catalytic performance for electrochemical reactions by fabricating highly active metal-perovskite heterogeneous interfaces. A series of B site doped (La0.2Sr0.8)0.925Ti0.55Mn0.35X0.1O3-δ (LSTMX, X = Ni, Co, and Fe) are synthesized and studied as the anodes of SOFCs with wet CH4 as the fuel. The X metal nanoparticles can be in situ exsolved in an anode atmosphere, and the generated active interfaces remarkably enhance the activity of the electrochemical oxidation of CH4. The stable perovskite substrate and the nanoparticles can also synergistically promote the elimination of deposited carbon. A single cell with the Ni-doped LSTMN anode delivers the optimal maximum power density of 388 mW cm-2 at 800 °C with wet CH4 as the fuel and an excellent output stability of 100 h at 700 °C, which is much higher than that with (La0.2Sr0.8)0.925Ti0.55Mn0.45O3-δ (LSTM) anodes. These results propose an effective strategy for the development of high-performance electrode materials for direct hydrocarbon SOFC applications.