Targeted Co substitution at Fe/Ti sites in La0.1Sr1.9TiFeO6-δ double perovskite oxides to improve CO2 reduction activity

This work focuses on the development of high-performance La 0.1 Sr 1.9 TiFeO 6-δ (LSTF)-based fuel electrode materials through targeted Co substitution at the Ti site and Fe site. By selectively substituting Ti or Fe with Co element, lattice contraction and change of the Fe 3 ⁺/Fe 4 ⁺ ratio in LSTF double perovskite are achieved. La 0.1 Sr 1.9 Ti 0.8 Co 0.2 FeO 6-δ (LSTCF) material obtains higher oxygen vacancy concentration and better CO 2 adsorption capacity. Electrochemical impedance spectroscopy (EIS) test demonstrates that the La 0.1 Sr 1.9 TiFe 0.8 Co 0.2 O 6-δ (LSTFC) electrode exhibits superior performance in gas transport process, while the LSTCF electrode demonstrates significant advantages in oxygen ion conductivity and dissociative adsorption of CO 2 species. The single cell with the LSTCF electrode exhibits superior electrolysis performance, achieving a current density of 1.07 A·cm −2 at 800 °C and 1.8 V for CO 2 electrolysis. This work provides a novel pathway for the development of catalysts for solid oxide electrolysis cell (SOEC) fuel electrodes.