Deep Oxidations in the Oxidative Dehydrogenation Reaction of Propane over V2O5(001): Periodic Density Functional Theory Study

作者:Dai Guo Liang; Li Zhen Hua; Lu Jing; Wang Wen Ning*; Fan Kang Nian
来源:Journal of Physical Chemistry C, 2012, 116(1): 807-817.
DOI:10.1021/jp208639t

摘要

The oxidative dehydrogenation (ODH) of propane to propene over a vanadium-based catalyst suffers from side reactions of further and complete oxidations of propene and other intermediates, which limit the yield of propene. These further oxidation reactions are also referred to as deep oxidation reactions of ODH. In this paper, we present a comprehensive study of the deep oxidation reactions in the ODH of propane over the V2O5(001) surface using the periodic density functional theory method. It is shown that the main source of deep oxidation byproducts originates from the dehydrogenation reaction of the surface intermediate isopropoxide, leading to acetone and the following deep oxidation reactions of acetone and propene. Thorough oxidation of acetone is more difficult than that of propene. Noticeably, formation of acetone and deep oxidation of acetone and propene are only feasible on the terminal oxygen site O(1) of the V2O5(001) surface. The bridging site O(2) has similar reactivity for propene formation but is inert for the side reactions, showing its superiority for selectivity of propane ODH.

全文