Performance enhancement of Cu decorated LSCM-GDC composite cathode for CO2 electroreduction

Abstract

LSCM perovskite is a promising ceramic cathode for direct CO2 electrolysis in solid oxide electrolysis cells (SOECs), but its application is limited by insufficient catalytic activity and stability. Herein, a novel strategy is proposed to improve electrolysis properties by modifying La0.75Sr0.25Cr0.5Mn0.5O3-δ-Gd0.2Ce0.8O2-δ (LSCM-GDC) backbone with Cu nanocatalyst. The metal-oxide interfaces between Cu NPs and ceramic backbone effectively increase the catalytic active sites and oxygen vacancy concentration, thus facilitating CO2 transport and reduction process. Consequently, Cu decorated cells achieve a peak current density of 1.33 A cm−2 (2 wt%) at 800 °C and 1.5 V, which is 2.5 times that of the bare LSCM-GDC electrode (0.53 A cm−2). Similarly, Rp value is considerably decreased by 70% at 800 °C from 2.20 Ω cm2 to 0.65 Ω cm2. Overall, decoration with Cu nanocatalyst provides new insights for LSCM based cathodes.