Coverage‐Dependent Behaviors of Vanadium Oxides for Chemical Looping Oxidative Dehydrogenation.

Chemical looping provides an energy‐ and cost‐effective route for alkane utilization. However, there is considerable CO2 co‐production caused by kinetically mismatched O2− bulk diffusion and surface reaction in current chemical looping oxidative dehydrogenation systems, rendering a decreased olefin productivity. Sub‐monolayer or monolayer vanadia nanostructures are successfully constructed to suppress CO2 production in oxidative dehydrogenation of propane by evading the interference of O2− bulk diffusion (monolayer versus multi‐layers). The highly dispersed vanadia nanostructures on titanium dioxide support showed over 90 % propylene selectivity at 500 °C, exhibiting turnover frequency of 1.9×10−2 s−1, which is over 20 times greater than that of conventional crystalline V2O5. Combining in situ spectroscopic characterizations and DFT calculations, we reveal the loading–reaction barrier relationship through the vanadia/titanium interfacial interaction. [ABSTRACT FROM AUTHOR]