Abstract:

The presence of polycyclic aromatic hydrocarbons in coal tar and heavy oil can reduce the quality of oil products and pollute the environment. In order to reduce the content of harmful substances in fossil resources， minimize environmental pollution， and prepare efficient light fuels， anthracene is used as a model compound for catalytic hydrogenation saturation of polycyclic aromatic hydrocarbons. A series of Pd/γ-Al₂O₃ catalysts with different mass fractions of La were prepared by impregnation method， and the effects of La introduction on the structure and properties of the catalysts， as well as the reaction performance of anthracene hydrogenation to fully hydrogenated anthracene， were investigated by characterization methods such as X-ray diffraction （XRD）， X-ray photoelectron spectroscopy （XPS）， and ammonia gas temperature programmed desorption （NH₃-TPD）. The results showed that the addition of an appropriate amount of La significantly improved the selectivity of fully hydrogenated anthracene. When the loading mass fraction of La metal was 1%， the temperature was 275 ℃， and a hydrogen pressure was 4 MPa， the conversion rate of anthracene hydrogenation is the highest， at 99.9%. The XRD characterization results of the catalyst showed that appropriate doping of metal La into Pd based catalyst reduced the metal particle size of the catalyst and improved the dispersion of Pd. The XPS characterization results indicate that the introduction of 1% La results in the highest content of Pd⁰ active metal and the best hydrogenation effect. The NH₃-TPD results indicate that a higher degree of weak acidity is beneficial for the deep hydrogenation of anthracene. This provides theoretical guidance for designing efficient precious metal catalysts to catalyze the synthesis of fully hydrogenated anthracene from anthracene.

Key words: Anthracene, Hydrogenation saturation, La-Pd bimetallic catalyst, Perfluoroanthrene