Oxygen vacancy-engineered cobalt-free Ruddlesden-Popper cathode with excellent CO2 tolerance for solid oxide fuel cells

Developing efficient and durable cobalt-free cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs) is indispensable on account of the sluggish oxygen reduction reaction (ORR). In this work, we report our findings in significantly improved ORR kinetics of (SrEu2)(0.9)Fe2O7-delta ((SE)(0.9)F) by introducing a 10% A-site deficiency in SrEu2Fe2O7 (SEF) at the atomic scale. Using this cation deficient strategy, sufficient oxygen vacancy concentration in (SE)(0.9)F lattice (delta = 0.40) is successfully achieved. Moreover, much improved electrical conductivity and promoted catalytic activity toward the ORR are observed in this new catalyst at intermediate temperatures (550-700 degrees C), which also offers excellent CO2 resistivity. This work demonstrates an integral role of Ruddlesden-Popper oxides in applying as highly efficient and stable cobalt-free cathodes for IT-SOFCs.

Automated summary

This study demonstrates the improved oxygen reduction reaction kinetics of (SrEu2)(0.9)Fe2O7-δ ((SE)(0.9)F) by introducing a 10% A-site deficiency, leading to sufficient oxygen vacancy concentration and enhanced electrical conductivity. The new catalyst also shows promoted catalytic activity towards the ORR at intermediate temperatures, with excellent CO2 resistivity, highlighting the integral role of Ruddlesden-Popper oxides in developing efficient and stable cobalt-free cathodes for IT-SOFCs.