Hydroxyl-Mediated Non-oxidative Propane Dehydrogenation over VOx /γ-Al2 O3 Catalysts with Improved Stability.

Supported vanadium oxides are one of the most promising alternative catalysts for propane dehydrogenation (PDH) and efforts have been made to improve its catalytic performance. However, unlike Pt-based catalysts, the nature of the active site and surface structure of the supported vanadium catalysts under reductive reaction conditions still remain elusive. This paper describes the surface structure and the important role of surface-bound hydroxyl groups on VOx  / γ-Al2 O3 catalysts under reaction conditions employing in situ DRIFTS experiments and DFT calculations. It is shown that hydroxyl groups on the VOx  /Al2 O3 catalyst (V-OH) are produced under H2 pre-reduction, and the catalytic performance for PDH is closely connected to the concentration of V-OH species on the catalyst. The hydroxyl groups are found to improve the catalyst that leads to better stability by suppressing the coke deposition.