Entropy-engineered perovskite cathodes: A novel approach for efficient and durable CO2 electrolysis

The application of solid oxide electrolysis cells (SOECs) for high-temperature CO2 reduction reaction (CO2RR) is constrained by the electrochemical activity and stability of the cathode materials. In this study, a series of iron- based perovskite oxides, designed by systematically varying A-site configurational entropy, are investigated as cathode materials for the CO2RR. Experimental results reveal that these high-entropy materials, derived from La 1/2 Sr 1/2 FeO 3_delta (LSF), exhibit high electrocatalytic activity and durability. Notably, the SOEC with La 1/5 Sr 1/ 5Pr1/5Ba1/5Ca1/5FeO3-delta (LSPBCF) cathode achieves a remarkable current density of 2.14 A cm _ 2 at 800 degrees C and 1.5 V, maintaining excellent stability over 120 h of operation with negligible fluctuations. Density functional theory (DFT) calculations further unveil the electronic structure modulation mechanism of the high-entropy material, revealing that A-site entropy engineering could enhance CO2 adsorption and activation by reducing the oxygen vacancy formation energy. This study underscores the potential of entropy engineering to improve the electrocatalytic performance and stability of other energy conversion systems.