Robust Cathode for Efficient CO 2 Electrolysis Driven by Entropy Engineering in Solid Oxide Electrolysis Cells

Herein, we introduce an innovative approach of entropy engineering to design high-performance and durable electrodes. A series of perovskite oxides with varying configurational entropy ( S config ) based on Pr 1/2 Ba 1/2 FeO 3−δ (PBF) matrix are synthesized, and their physicochemical properties and electrochemical performances in CO 2 reduction reaction process are explored via manipulating S config . Notably, a high-entropy perovskite, Pr 1/6 La 1/6 Sm 1/6 Ba 1/6 Sr 1/6 Ca 1/6 FeO 3−δ (PLSBSCF), with an S config of 1.79 R, exhibits significant lattice distortion due to homogeneous distributed A-site elements. It demonstrates a high concentration of oxygen vacancies, good CO 2 adsorption capability, and rapid O 2– /e – conductions. Compared to bare PBF perovskite, PLSBSCF offers a greater number of active sites for CO 2 RR, and the corresponding cell achieves remarkably high current densities of 2.86 A cm –2 at 850 °C (1.5 V) during direct CO 2 electrolysis, while maintaining good thermal stability and operational durability. Density Functional Theory calculations also confirm the good CO 2 reduction activity of PLSBSCF perovskite.