Intrinsic kinetic model for oxidative dehydrogenation of ethane over MoVTeNb mixed metal oxides: A mechanistic approach

An intrinsic kinetic model for the selective production of ethene via oxidative dehydrogenation of ethane over the M1 phase of MoVTeNb mixed metal oxides is presented. Formation of acetic acid, carbon monoxide and carbon dioxide has been incorporated using a holistic reaction mechanism. The proposed model is based on two different oxygen sites, namely, lattice oxygen causing carbon-hydrogen bond cleavage and electrophilic surface oxygen responsible for the formation of carbon-oxygen bonds. It is found that carbon dioxide exclusively originates from decarboxylation of acetate species, while ethene selectively reacts to CO. Consumption and formation of all species are well predicted by the proposed model. Sensitivity analyses demonstrate the strong impact of the initial carbon-hydrogen cleavage on the net ethene production rate. Moreover, regeneration of lattice oxygen sites is found to become rate-determining at oxygen-lean conditions.