Synergistic multielement effect at the B-site of high entropy double perovskite oxide: A promising fuel electrode for efficient co-electrolysis of H2O and CO2

The performance of the fuel electrode in a solid oxide electrolysis cell (SOEC) is crucial to facilitating fuel gas electrolysis and is the key determinant of overall electrolysis efficiency. Nevertheless, the commercialization of integrated CO2-H2O electrolysis in SOEC remains constrained by suboptimal catalytic efficiency and long-term stability limitations inherent to conventional fuel electrode architectures. A novel high-entropy Sr2FeTi0.2Cr0.2Mn0.2Mo0.2Co0.2O6-δ (SFTCMMC) is proposed as a prospective electrode material of co-electrolysis in this work. The physicochemical properties and electrochemical performance in the co-electrolysis reaction are investigated. Full cell is capable of electrolyzing H2O and CO2 effectively with an applied voltage. The effects of temperature, H2O and CO2 concentrations, and applied voltage on the electrochemical performance of Sc0.18Zr0.82O2-δ (SSZ)-electrolyte supported SOEC were investigated by varying the operating conditions. The SOEC obtains a favorable electrolysis current density of 1.47 A cm-2 under co-electrolysis condition at 850°C with 1.5 V. Furthermore, the cell maintains stable performance for 150 h at 1.3 V, and throughout this period, no carbon deposition is detected. The promising findings suggest that the high-entropy SFTCMMC perovskite is a viable fuel electrode candidate for efficient H2O/CO2 co-electrolysis.