Synergistic dual-exsolved Co-Ni nanoparticles on lanthanide perovskite/fluorite heterostructures for efficient high-temperature CO2 electrolysis

Enhancing the sluggish kinetics of the CO 2 reduction reaction (CO 2 RR) is crucial for the efficient CO 2 -to-CO conversion in solid oxide electrolysis cells. Herein, a dual-exsolution strategy is reported to simultaneously anchor Co and Ni nanoparticles onto distinct La 0.6 Sr 0.4 Co 0.7 Mn 0.3 O 3– δ (LSCM) perovskite phase and Ce 0.9 Ni 0.1 O 2– δ (CNO) fluorite phase, respectively. This design activates both electronic and ionic conduction pathways. The resulting cathode achieves a remarkable CO 2 electrolysis current density of 1.48 A/cm 2 at 1.5 V and 800 °C, representing a 54% enhancement over its non-exsolved counterpart and exhibits stable operation for 100 h. Combined experimental and theoretical analyses reveal that the synergistic Co-Ni bimetallic sites, along with abundant oxygen vacancies, cooperatively enhance CO 2 adsorption and dissociation. Density functional theory calculations provide insights into the intrinsic activity of the newly formed Co@LSCM and Ni@CNO heterointerfaces. This work provides a promising route for designing high-performance composite electrodes via dual-phase engineering.