Nd-doping-induced perovskite/Ruddlesden-Popper heterointerfaces boost the ORR activity and CO2 tolerance for SrFeO3-δ-based cathode.

The development of cathode materials with high oxygen reduction reaction (ORR) activity is crucial to realize the wide application of solid oxide fuel cells. Nd-doped SrFeO 3-δ (SNF) two-phase nanocomposite was fabricated by a dopant-induced in situ self-assembly process. The SNF nanocomposite comprises 63.4 wt% perovskite main phase (P–SNF) and 36.6 wt% Ruddlesden-Popper second phase (RP-SNF). The average thermal expansion coefficient (TEC) of SrFeO 3-δ is reduced by 36.5 % and down to 13.9 × 10−6 K−1. At 750 °C, SNF demonstrates an impressive output power of 779 mW cm−2, which is twice that of the single-phase SrFeO 3-δ. The superior performance stems from the heterointerface effect of the in situ self-assembled two phases. This effect increases the content of oxygen vacancies, thereby enhancing both chemical oxygen surface exchange coefficient and bulk diffusion coefficient. Moreover, the SNF composite exhibits excellent CO 2 tolerance than the single-phase SrFeO 3-δ. This work presents a promising avenue for exploring multifunctional materials through interface engineering, offering new possibilities for future energy conversion devices. [ABSTRACT FROM AUTHOR]