Fe‐Doped Ceria‐Based Ceramic Cathode for High‐Efficiency CO<sub>2</sub> Electrolysis in Solid Oxide Electrolysis Cell
Lijie Zhang, Yunan Jiang, Kang Zhu, Nai Shi, Zohaib Ur Rehman, Ranran Peng, Changrong Xia
Abstract
Abstract In the quest for sustainable energy solutions, solid oxide electrolysis cell (SOEC) emerges as a key technology for converting CO 2 into fuels and valuable chemicals. This work focuses on pure ceramic Fe x Sm 0.2 Ce 0.8 O 2‐ δ (xFe‐SDC) as the fuel electrodes, and Sr‐free ceria‐based ceramic electrodes can be successfully constructed for x ≤ 0.05. The incorporation of Fe into the ceria lattice increases the oxygen vacancy concentration and promotes the formation of catalytic sites crucial for the CO 2 reduction reaction (CO 2 RR). Density functional theory calculations indicate that Fe enhances electrochemical performance by decreasing the CO 2 RR energy barrier and facilitating oxygen ion diffusion. At 800 °C and 1.5 V, single cells with 0.05Fe‐SDC cathodes manifest attractive performance, attaining current densities of −1.98 and −2.26 A cm −2 under 50% CO 2 /CO and pure CO 2 atmospheres, respectively. These results suggest the great potential of xFe‐SDC electrodes as promising avenues for high‐performance fuel electrodes in SOEC.