Achieving High-Efficiency CO₂ Electrolysis for SrFeO_3-δ-Based Symmetric Electrodes

Abstract

In situ exsolution of nanoparticles has been reported to be an efficient path to optimize CO 2 electrolysis performance. Herein, a Ce/Co co-doped SrFeO 3-δ (SF) can achieve the co-exsolution of CeO 2 and Co−Fe alloy in 5% H 2 at 800 °C. A small amount (<10%) of Ce-doped SF cannot stabilize the perovskite structure in a reducing atmosphere. Sr 0 . 9 Ce 0 . 1 Fe 0 . 9 Co 0 . 1 O 3 (10Ce10CoF) and Sr 0.95 Ce 0.05 Fe 0.9 Co 0.1 O 3 (5Ce10CoF) as symmetric electrodes of solid oxide electrolysis cells showed an excellent electrolysis performance at 800 °C for CO 2 electrolysis. The current densities of the cells with 5Ce10CoF and 10Ce10CoF reached 0.98 and 1.30 A cm −2 under a bias of 1.3 V after a 48 h durability test for CO 2 electrolysis, respectively, and the performance difference, however, may be due to CeO 2 being more easily exsolved from the 10Ce10CoF lattice. We also investigated the role of the exsolved CeO 2 and oxygen vacancy (V O ) in determining the CO 2 electrolysis performance via theoretical calculation. In this work, we designed a novel strategy to achieve the exsolution of CeO 2 and Co−Fe alloy via reduction treatment and showed an outstanding CO 2 electrolysis performance.