Abstract:

In order to further improve the activity and stability of heavy aromatic light catalyst,four catalysts with different n（Ni）/n（Ni+Mo） atomic ratios were prepared by incipient-wetness impregnation method with zeolite β as support.The total mass of the metal was same.The catalysts were characterized by XRD,NH₃-TPD,H₂-TPR,H₂-TPD and TG-DTG.The results showed that the acid content and acid strength of the four catalysts were similar,and when the n（Ni）/n（Ni+Mo） atomic ratio was of standard+0.2,the interaction between Mo and the support was the weakest,with the maximum adsorption capacity of H₂ and the minimum carbon deposition.Four catalysts were evaluated by using reforming C₁₀⁺ heavy aromatics.The results showed that the catalyst with the n（Ni）/n（Ni+Mo） atomic ratio of standard+0.2 had the optimal catalytic activity and stabi-lity.The above results showed that the key factor affecting the activity and stability of catalyst was the amount of H₂ adsorption,the more H₂ was adsorbed,the more obvious the hydrogen overflow effect was on metal surface.The precursor of carbon deposition was eliminated in time by overflow hydrogen,thus,the hydrogenation active center of the catalyst was protected from carbon deposition,it was helpful to keep the catalyst stable at high activity.

Key words: heavy aromatics to light aromatics, catalyst, hydrogenation, n（Ni）/n（Ni+Mo） atomic ratios