Reinforced surface reactivity via incorporation of metal catalyst onto perovskite oxide for CO2 reduction

Solid oxide electrolysis cells (SOECs) for CO 2 electrolysis are a promising path to renewable energy storage. Here, we systematically investigate the catalytic performance of various metals (Ru, Co, Fe, and Ni) by incorporating them into (La 0.75 Sr 0.25 ) 0.97 Cr 0.5 Mn 0.5 O 3 (LSCM) electrodes for SOECs. Each metal exhibits different performance characteristics under different conditions. LSCM-Fe achieves the highest current density (2.45 A cm −2 at 1.5 V) at 850 °C with CO 2 /CO (50:50). At lower temperatures (700 °C), LSCM-Ru shows the highest current density of 0.56 A cm −2 at 1.5 V. Under pure CO 2 , LSCM-Ru shows high performance (2.06 A cm −2 at 800 °C and 1.5 V), a 2.2-fold improvement over bare LSCM. CO 2 -temperature-programmed desorption, in-situ X-ray photoelectron spectroscopy, and density functional theory calculations reveal that the Ru catalyst exhibits electron-donating properties, facilitating enhanced CO 2 reduction. Based on these findings, we apply simple and scalable ultrasonic spraying techniques to incorporate the Ru catalyst. We achieve current densities of 3.23 A cm −2 and 2.26 A cm −2 at 850 °C and 800 °C, respectively, at 1.5 V under pure CO 2 , with an efficiency close to 95%. This work provides insights into catalyst-specific mechanisms and a framework for the development of efficient SOEC for sustainable energy systems.