Formation of brownmillerite type calcium ferrite (Ca2Fe2O5) and catalytic properties in propylene combustion

Several types of calcium ferrite base catalysts (Ca/Fe = 0.33–3) for propylene (C3H6) combustion were prepared. Calcium ferrite catalyst with brownmillerite crystal structure provided catalytic activity for C3H6 combustion in the temperature range of 250–450 °C. The brownmillerite phase (Ca2Fe2O5) was responsible for the formation of oxygen adspecies (O2−) in the surface layer below 450 °C.