(513ak) SiO2 Supported La0.5Ba0.5FeO3 Composite Pellets for Low-Temperature Thermochemical Conversion of Carbon Dioxide

Reverse water-gas shift chemical looping (RWGS-CL) is a thermochemical process to convert carbon dioxide to carbon monoxide at a moderate temperature with high selectivity. The resulting carbon monoxide can be subsequently used for chemical energy storage in the form of hydrocarbon-based fuels and chemicals. Based on the catalyst requirements of RWGS-CL, this research focused on the synthesis and characterization of the La_xBa_1-xFeO₃ perovskite-type catalysts, which can form oxygen vacancies for CO₂ conversion. Perovskite oxides catalysts were further made to pellets with SiO₂ support through tableting and extrusion. For both two methods, water and binder composition were adjusted to make the pellets to satisfy the mechanical property. Temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), and chemical looping experiments were performed to identify reaction temperatures, compare redox properties, and calculate CO yields. The 50 cycles long term RWGS-CL experiments were applied to test the stability of pellets. X-ray diffraction was utilized to identify the crystal structure. The results showed the La_0.5Ba_0.5FeO₃ / SiO₂ pellets convert CO₂ to CO at the semi-batch reactor through a long term RWGS-CL at a comparatively low temperature of 550 °C and a high yield of 2000 μmol/g_catalyst.