Investigation into Lattice Oxygen Migration Behavior and Ethylene Selectivity of LaCuO ₃ Perovskite Oxygen Carriers for Ethane Oxidative Dehydrogenation

Understanding lattice-oxygen participation and migration in LaCuO 3 oxygen carriers is essential for optimizing chemical looping oxidative dehydrogenation of ethane (CL-ODHE). Herein, the lattice-oxygen migration behavior and ethylene selectivity mechanism of a LaCuO 3 oxygen carrier were investigated by combining density functional theory (DFT) calculations with experimental characterization. DFT results show that oxygen-vacancy formation and bulk-to-surface lattice-oxygen migration are energetically feasible, enabling the continuous supply of reactive lattice oxygen during redox cycling. DOS and COHP analyses indicate that Cu participates in charge redistribution and regulates the metal–oxygen bonding environment, thereby facilitating lattice-oxygen activation. Adsorption and reaction-pathway calculations further suggest that La-related sites favor C 2 H 6 adsorption and initial C–H activation, while the calculated free-energy profile indicates a thermodynamic preference for the C 2 H 6 -to-C 2 H 4 oxidative dehydrogenation pathway. Experimentally, TGA confirms reversible oxygen release and replenishment, while XRD and XPS reveal coupled phase evolution, lattice-oxygen consumption, oxygen-vacancy formation, and reoxidation-induced oxygen replenishment. Cycling tests further demonstrate stable oxygen release/replenishment capacity, while redox-induced morphological evolution may contribute to improved gas–solid contact and redox kinetics. Overall, these results support a mechanism in which lattice oxygen in the LaCuO 3 oxygen carrier is consumed, replenished, and redistributed during redox cycling, thereby promoting selective ethane-to-ethylene conversion.