Synthesis of perovskite-ceria composites for solar-to-fuel conversion

Abstract

Finding suitable replacements for fossil fuels is key to a more sustainable energy economy. This thesis investigated the effectiveness of novel composite materials made from previously researched state-of-the-art materials as catalysts in the thermochemical solar-to-fuel conversion process. Materials such as ceria and gadolinium-doped ceria (GDC) have been determined to have excellent kinetics for this process but have a very high operating temperature. In contrast, perovskites have the advantage of a lower operating temperature but it comes at the expense of lower production rates. Composites containing ceria/GDC/YSZ and perovskite were synthesized to explore synergies that may result in improved performance as a catalyst for the fuel conversion process. Two of these perovskite-ceria composites, LSCF-GDC and LSCC-ceria, showed promise as materials that perform better than their respective individual components. Improved fuel production and oxygen release was observed with these composites in specific temperature regimes (1000-1100°C for oxidation, 1200°C for reduction).