Achieving Highly Efficient Carbon Dioxide Electrolysis by In Situ Construction of the Heterostructure

The design of active cathode catalysts, with abundant active sites and outstanding catalytic activity for CO₂ electroreduction, is important to promote the development of solid oxide electrolysis cells (SOECs). Herein, A-site-deficient perovskite oxide (La_0.2Sr_0.8)_0.9Ti_0.5Mn_0.4Cu_0.1O_3-δ (LSTMC) is synthesized and studied as a promising cathode for SOECs. Cu nanoparticles can be rapidly and uniformly in situ-exsolved under reducing conditions. The heterostructure formed by the exsoluted Cu and LSTMC provides abundant active sites for the catalytic conversion of CO₂ to CO. Combined with the remarkable oxygen-ion transport capacity of the LSTMC substrate, the specially designed Cu@LSTMC cathode exhibits a dramatically improved electrochemical performance. Furthermore, first-principles calculations proposed a mechanism for the adsorption and activation of CO₂ by the heterostructure. Electrochemically, the Cu@LSTMC presents a high current density of 2.82 A cm^-2 at 1.8 V and 800 °C, which is about 2.5 times higher than that of LSTM (1.09A cm^-2).