In this study, Mg6MnO8 modified with Li2WO4 and/or Na2WO4 were synthesized and used as oxygen carriers for the chemical looping oxidative dehydrogenation (CL-ODH) of ethane. The Mg6MnO8-LiNaW2 sample demonstrates observable performance, surpassing that of most previously reported promoter-modified composite metal oxides, achieving 77.7% ethane conversion, 86.5% ethylene selectivity, and 67.2% H2 conversion. TG analysis indicates that the Mg6MnO8-LiNaW2 effective lattice oxygen capacity is up to 3.5% and has excellent reactivity above 725°C. Morphology characterization unveils that Mg6MnO8-LiNaW2 has a core-shell structure with a loose and porous surface, which could alleviate agglomeration effectively during the cyclic process. XPS results reveal that the co-doping of Li-Na-W facilitate the diminution of surface OH-/CO32- and Mn4+ species, favoring the stabilization of the surface species during the cyclic process and enabling stable reaction performance in 20 redox experiments. DFT calculations indicate that the co-doping of Li-Na-W on the surface of Mg6MnO8 effectively decreases the electron loss from the oxygen carrier surface and promotes the formation of oxygen vacancy.
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