No abstract

Constructing nanostructure through exsolution has been demonstrated as an effective approach to produce electrode materials with superior performance and stability in the application of solid oxide cells, primarily due to the excellent catalytic properties as well as the significantly enhanced stability offered by the well-embedded nanoparticles that are exsolved from a supporting oxide. In this work, we focus on investigating the titanate perovskites with exsolved Ni-Co alloy nanocatalysts as fuel electrode of solid oxide cells (SOCs), particularly on operando generating these nanomaterials via applying a potential bias in CO2 electrolysis operating conditions. Three compositions of titanate perovskite were examined, including La0.43Ca0.37Ti0.94Ni0.06O3-δ (LCT-Ni6), La0.43Ca0.37Ti0.94Ni0.03Co0.03O3-δ (LCT-Ni3Co3), and La0.43Ca0.37Ti0.90Ni0.05Co0.05O3-δ (LCT-Ni5Co5). Various techniques, including X-ray diffraction, thermogravimetric analysis, DC conductivity measurement etc., were applied to study the crystal structure, reduction behavior, conductivity property and microstructure of these materials. SOCs with these titanate fuel electrodes were fabricated and evaluated, with emphasis placed on operando generation of active nanomaterials through electrochemical switching in pure CO2 atmosphere, and on understanding the materials properties linking to their microstructure and performance towards CO2 electrolysis and H2 fuel cell.