Mossbauer study of perovskite oxides for oxidative coupling of CH4 and absorption of CO2

Perovskite oxides, (Ba0.95Ca0.05)(Co1-xFex) O3-delta, are prominent materials for oxidative coupling of methane and for CO2 absorption at high temperature, and these oxides before and after treatment in CH4 and CO2 atmosphere were analysed by Mossbauer spectroscopy. The perturbation of microstructure by substitution of Ha sites with Ca, and the electron transfer of mixed valences in Fe and Co ions with the formation of oxygen vacancies at high temperatures, are considered to contribute strongly to the selectivity of CH4 coupling and the rapid absorption of CO2 at high temperatures.