Combustion synthesized A0.5Sr0.5MnO3-δ perovskites (where, A = La, Nd, Sm, Gd, Tb, Pr, Dy, and Y) as redox materials for thermochemical splitting of CO2

Abstract

In this paper, A0.5Sr0.5MnO3 perovskites (where, A = La, Nd, Sm, Gd, Tb, Pr, Dy, and Y) were examined towards thermochemical CO2 splitting (CS) reaction. The solution combustion synthesis (SCS) method was employed for the preparation of the A0.5Sr0.5MnO3 perovskites, in which glycine was used as the fuel. The characterization of the as-prepared and reacted A0.5Sr0.5MnO3 perovskites was accomplished by means of powder X-ray diffractometer (PXRD), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS). A Seteram Setsys Evolution TGA set-up was utilized to estimate the amounts of O2 released (nO2) and CO produced (nCO) by each SCS synthesized A0.5Sr0.5MnO3 perovskite in multiple thermochemical cycles. Obtained TGA results confirmed that all the A0.5Sr0.5MnO3 perovskites attained thermal and redox stability from second thermochemical cycle. It was also understood that all the A0.5Sr0.5MnO3 perovskites shows significantly higher nO2 and nCO as compared to the phase pure CeO2. Among all the A0.5Sr0.5MnO3 perovskites investigated, PrSM shows maximum nO2 = 144.8 μmol/g·cycle and nCO = 252.3 μmol/g·cycle with an average CO/O2 molar ratio of 1.74. The experimental findings also indicate that the fuel production aptitude of all the A0.5Sr0.5MnO3 perovskites can be upsurged if longer CS reaction time is employed.