Catalytic aromatization of ethane on zinc-modified zeolites of various framework types

Zeolites of the ZSM-5, ZSM-8, ZSM-11, and ZSM-12 framework types have been prepared by hydrothermal synthesis from alkaline alumina-silica gels, and modified with zinc by the impregnation method. The acid properties of the zeolites have been examined, and it has been found that the catalysts differ from one another in distribution and relative amount of acid centers of various types. The feasibility of the direct chemical conversion of ethane to aromatic hydrocarbons on the zinc-containing zeolites of various framework types has been shown. It has been found that the structure of high-silica zeolites affects the activity and selectivity of the zinc-containing catalysts prepared from them. It has been shown that the most effective catalyst for the ethane-to-aromatics conversion process is the zinc-modified ZSM-5 type zeolite.