Coverage‐Dependent Behaviors of Vanadium Oxides for Chemical Looping Oxidative Dehydrogenation
Sai Chen, Chunlei Pei, Xin Chang, Zhi‐Jian Zhao, Rentao Mu, Yiyi Xu, Jinlong Gong
Abstract
Abstract Chemical looping provides an energy‐ and cost‐effective route for alkane utilization. However, there is considerable CO 2 co‐production caused by kinetically mismatched O 2− 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 CO 2 production in oxidative dehydrogenation of propane by evading the interference of O 2− 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 V 2 O 5 . Combining in situ spectroscopic characterizations and DFT calculations, we reveal the loading–reaction barrier relationship through the vanadia/titanium interfacial interaction.