(621da) Multi B-Site Substituted La(Co1-X-YFeXMnY)O3 Perovskites for the Conversion of Carbon Dioxide to Carbon Monoxide By Thermochemical Cycles

The effect of transition metals interactions in the B site of a perovskite on the adsorption of CO₂ and its conversion to CO were investigated. Four perovskites: LaCo_0.33Fe_0.33Mn_0.33O₃, LaCo_0.50Fe_0.25Mn_0.25O₃, LaCo_0.25Fe_0.50Mn_0.25O₃ andLaCo_0.25Fe_0.25Mn_0.50O₃ were synthesized by the Pechini method and characterized with X-ray diffraction and temperature-programmed reduction. Their oxygen vacancies formation capabilities were tested in an inert environment using mass spectrometry and thermogravimetric analysis (TGA). The influence of the different Co, Fe and Mn doping on carbon dioxide adsorption strength was also tested and a comparison was established with adsorption strength calculations from DFT. The conversion of CO₂ to CO on the oxygen vacancies of the materials was also tested with TGA. The perovskite with higher conversion activities was studied in Thermochemical Cycles experiments, in which the perovskite is heated under inert until formation of oxygen vacancies. Then, it is cooled under CO₂ while CO is formed.