Abstract: The effect of zinc modified ZRP zeolite catalyst on the aromatization of FCC naphtha was studied using a fixed bed micro-reactor, and the function of zinc on the aromatization reaction was investigated. Through analyzing the surface acidity of catalyst prior and post to Zn modification from pyridine adsorption FT-IR spectra, the aromatization reaction mechanism of FCC naphtha over Zn/ZRP zeolite catalyst was proposed. Test results showed that the aromatization performance of ZRP zeolite catalyst was improved significantly by Zn modification. By discussing the reaction mechanism, it was found that the aromatization of FCC naphtha over ZRP zeolite catalyst was mainly through hydrogen transfer reactions, yet over Zn/ZRP zeolite catalyst was mainly through cyclization and dehydrogenation reactions assisted by hydrogen transfer reactions, besides, cracking, oligomerization and isomerization reactions were implicated as well. [Zn(OH)]+ active sites having both B/L acid functions might exist in the channels of Zn/ZRP zeolite to meet the requirements of aromatization reaction in various stages, thus the aromatization performance of ZRP zeolite catalyst was enhanced by Zn modification.

Key words: FCC naphtha, Zn modification, aromatization, mechanism