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_1/2Sr_1/2FeO_3-δ (LSF), exhibit high electrocatalytic activity and durability. Notably, the SOEC with La_1/5Sr_1/5Pr_1/5Ba_1/5Ca_1/5FeO_3-δ (LSPBCF) cathode achieves a remarkable current density of 2.14 A cm^-2 at 800 °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.