Ce-modified SrFeO3-δ for ethane oxidative dehydrogenation coupled with CO2 splitting via a chemical looping scheme

The current study investigates Ce-modified SrFeO 3- δ oxygen carriers for oxidative dehydrogenation (ODH) of ethane coupled with CO 2 splitting in a chemical looping manner. During 39 cycles of redox testing over the sample of 0.2Ce/SrFeO 3 , up to 29% ethane conversion and 82% ethylene selectivity are achieved, and the CO generation in the subsequent CO 2 splitting step is 0.25 mmol/g. XPS characterization results indicate decreased Fe 2+ /(Fe 3+ +Fe 4+ ) ratio as well as increased active oxygen species proportion on the near-surface of Ce-modified samples, which are responsible for the improved activity of the 0.2Ce/SrFeO 3 in ethane ODH reaction. DFT calculations further reveal that the increased ODH activity of 0.2Ce/SrFeO 3 is due to the lower surface oxygen vacancy formation energy upon Ce promotion. Moreover, the higher resistance of lattice oxygen diffusion from the bulk to the surface is the main reason for the superior ethylene selectivity attained by the CO 2 -regenerated sample than that by O 2 regeneration.