Enhancing CO2 reduction via Cu nanocrystals decorated perovskite as cathode for solid oxide electrolysis cells

Solid oxide electrolysis cells (SOECs) are promising energy conversion devices capable of efficiently converting CO₂ into valuable products taken the advantage of heat and renewable electricity sources. The performance of SOECs is largely influenced by the cathode material, which governs the electrochemical reduction of CO₂. In this work, we engineered metal-perovskite cathode by pre-depositing Cu nanocrystal onto the surface of La_0.1Ca_0.9Fe_0.1Ti_0.9O_3-δ (LCFT) cathode to well understand the effects of Cu metal nanocrystal in high temperature CO₂ reduction. This Cu nanocrystal deposition on cathode resulted in a significant reduction in polarisation resistance of SOEC by 50 % improved current density from 310 mA cm⁻² to 456 mA cm⁻² at 1.6 V. The cell also exhibits good stability over 100 h without obvious degradation. Extensive structural and chemical analyses indicate the deposited Cu nanocrystal facilitated the formation of oxygen vacancies and metal-oxide interface which should attribute to the enhanced electrochemical performance. This study provides new insights into the role of metal decoration in facilitating the high temperature direct CO₂ electrolysis performance.