Fluorine-Stabilized BO<sub>6</sub> Octahedron of Host Perovskites for Robust Carbon Dioxide Electrolysis on Exsolved Catalysts
Bowen Zhang, Mengnan Zhu, Min‐Rui Gao, Xiaoyu Liu, Jing Shen, Xiuan Xi, Nanqi Duan, Natalia Semagina, Hongbo Zeng, Jing‐Li Luo
Abstract
Exsolution of nanoparticles has become a prevalent technique for enhancing the catalytic activity of perovskites for carbon dioxide (CO 2 ) electrolysis in solid oxide electrolysis cells. However, the potential negative impact of phase evolution of the host perovskite on catalytic performance is often overlooked in light of the overall performance enhancement from exsolution. Herein, we illustrate a facile fluorine doping strategy to suppress the phase transition of Sr 2 Fe 1.2 Ni 0.3 Mo 0.5 O 6 –δ (SFN 3 M) during exsolution. The experimental characterizations combined with density functional theory calculations reveal that the incorporation of fluorine into the SFN 3 M lattice is beneficial for preserving the high oxidation states of B-site cations and inhibiting the lattice oxygen loss, resulting in a robust BO 6 octahedron in the host perovskite. It is found that the well-preserved double perovskite structure exhibits a stronger interaction with CO 2, thus enhancing the catalytic activity of F-doped exsolved SFN 3 M (F-SFN 3 M-red). Furthermore, the robust BO 6 octahedron of the host perovskite significantly enhances the resistance of F-SFN 3 M-red to decomposition under high-voltage CO 2 electrolysis, leading to the significantly increased carbon monoxide productivity over a broad voltage range. These findings highlight that the F doping strategy has great potential to aid the development of exsolved perovskites with high catalytic activity and stability for a wider range of electrocatalysis applications.