Tuning the Phase Transition of SrFeO 3-δ by Mn toward Enhanced Catalytic Activity and CO 2 Resistance for the Oxygen Reduction Reaction

• Published in: ACS applied materials & interfaces 2022-04, Vol.14 (15), p.17358-17368
• Main Authors: Zhang, Lu, Huan, Daoming, Zhu, Kang, Dai, Pengqi, Peng, Ranran, Xia, Changrong
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.2c01339

Developing high-performance cathodes with sufficient stability against CO rooting in ambient atmosphere is crucial to realizing the practical application of solid-oxide fuel cells. Herein, the Mn dopant is investigated to regulate the phase structure and cathode performance of SrFeO perovskites through partially replacing the B-site Fe. Compared with parent SrFeO , Mn-doped materials, SrFe Mn O ( = 0.05 and 0.1), show stabilized cubic perovskites at room temperature. Meanwhile, doping Mn accelerates the oxygen reduction reaction process, showing a reduced polarization resistance of 0.155 Ω·cm at 700 °C for SrFe Mn O , which is less than 30% of SrFeO . In addition, the Mn dopant improves the chemical oxygen surface exchange and bulk diffusion coefficients. Furthermore, Mn enhances the tolerance toward CO corrosion in various CO atmospheres. Density functional theory calculations also reveal that Mn can strengthen the structural stability and increase the activity for the oxygen reduction reaction.