• NaNO3 doping on Ca2MnO4 significantly enhances ethylene selectivity in CL-ODH of ethane, achieving 68.17% conversion and 57.39% yield at 750 °C.
• XPS analysis reveals that NaNO3 reduces Mn oxidation state and increases lattice oxygen content, contributing to improved catalytic performance.
• The NaNO3 shell on Ca2MnO4 surface reduces manganese site concentration and modulates oxygen release in a step-wise manner, boosting ethylene selectivity.
• Ca2MnO4-layered perovskites emerge as promising redox catalysts for chemical-looping oxidative dehydrogenation, offering a more energy-efficient and environmentally friendly route to ethylene production.