关键词: Ga₂O₃, 丙烷, 脱氢, CO₂, 反应机理

Abstract: Dehydrogenation of propane to propene in the presence or absence of CO₂ over gallium oxide was investigated. Ga₂O₃ exhibited the high dehydrogenation activity, which was even more active than chromium oxide catalyst. The dehydrogenation reaction was suggested to proceed through a heterolytic dissociation reaction pathway instead of a redox mechanism, and it was enhanced by CO₂ due to the existence of the reverse water gas shift reaction and the Boudouard reaction. This promotion effect of CO₂ was more evident at above 823 K. The high catalytic activity of Ga₂O₃ was probably associated with an abundance of surface medium-strong acid sites related to the coordinatively unsatured Ga³⁺ cations and the conjugated effect of proton and oxide. The deactivation of the catalyst was due to the coke deposition as well as the loss of the active oxygen species on the surface which could not be recovered during the regeneration.

Key words: Gallium oxide, Propane, Dehydrogenation, Carbon dioxide, Reaction mechanism