Oxidative dehydrogenation of ethane over La1-xSrxFeO3-delta perovskite oxides

Catalysts of the composition La1-xSrxFeO3-delta, 0 less than or equal to x less than or equal to 1, have been tested for the oxidative dehydrogenation of ethane in the temperature range 300-800 degrees C. The catalyst is active above 400 degrees C, giving a maximum yield of 37% ethylene at 650 degrees C. Above 650 degrees C, synthesis gas was formed together with methane, suggesting that the reforming reaction and thermal cracking of ethane took place. The catalytic data are compared to conductivity measurements on the same material, and a good correlation between the activity and p-type conductivity has been found. In the phase diagram for the system LaFeO3-SrFeO3-delta, a phase separation to two types of (La, Sr)FeO3-delta perovskites was observed in the La/Sr binary composition in the temperature range below 800 degrees C. The phase separation can elucidate the dependency of the catalytic activity on its p-type conductivity.