The Role of Li2WO4-Modification in Modulating Electron Transfer and Oxygen Mobility of LaMnO3 Perovskites for Chemical Looping Oxidative Dehydrogenation of Ethane

Ethylene is a fundamental feedstock in the chemical industry. Oxidative dehydrogenation (ODH) of ethane offers a promising route for ethylene production, as it avoids thermodynamic equilibrium limitations and mitigates coke formation. However, the conventional co-feeding of ethane and oxygen raises concerns regarding operational cost and safety risks. Chemical looping oxidative dehydrogenation (CL-ODH) addresses these issues by using lattice oxygen instead of gaseous oxygen to convert ethane into ethylene. Nevertheless, existing CL-ODH process still suffer from low ethane conversion, limited ethylene selectivity, and inadequate stability, primarily due to the over-reactivity of lattice oxygen leading to deep oxidation. In this work, we used Li 2 WO 4 -modified LaMnO 3 to suppress over-oxidation. This catalyst exhibits outstanding performance, achieving 66.0% ethane conversion, 91.0% ethylene selectivity, and 60.1% ethylene yield, while maintaining good stability over 25 cycles at 750°C. We attribute such high ethylene yield to the modulation of bulk lattice oxygen and electron distribution around Mn sites via formation of interfacial Mn─O─W bridged moiety. The enhanced ethylene selectivity originates from the dynamic generation and consumption of bridging oxygen species in the Mn─O─W moiety. The tailored electronic and local chemical environment of active sites strengthens ethane adsorption and facilitates ethylene desorption, thereby boosting ethylene selectivity. Graphical The formation and consumption of bridging oxygen atoms in the Mn─O─W bridging structure at the interface dynamically regulate the charge distribution around the Mn sites. This tailored electronic environment enhances the adsorption of ethane and promotes the desorption of ethylene, thereby improving ethylene selectivity.