Carbon dioxide decomposition through gas exchange in barium calcium iron niobates

A number of metal oxides and perovskites are capable of being reduced at high temperatures and then re oxidised in the presence of CO2 or H2O to form CO or H-2. Barium calcium iron niobates have been found to be redox-active in this way. The redox activity of these perovskites was explored, and the chemical and physical stability was investigated using EDX and SEM imaging, respectively. The most promising, Ba2Ca0.66Nb0.34FeO6-delta (BCNF1), showed mass changes of 0.45 % after five cycles of reduction with N-2 and re-oxidation with 10 % CO2. BCNF1 is chemically stable as it shows no changes in XRD and shows no evidence of sintering, although cracking of the pellets was observed after re-oxidation. The low enthalpy of re-oxidation of BCNF1 coupled with the high and sustained mass change makes this perovskite suitable for chemical looping use for energy storage and conversion systems.

Automated summary

A new type of perovskite material BCNF1 has been studied, showing good stability and high mass changes in reduction and re-oxidation cycles, making it suitable for energy storage and conversion systems.