Abstract: The isomerization of ethylcyclohexane (ECH) was investigated via three types of shape selective molecular sieve, ZSM-5, MOR and EU-1. The structural and acidic properties of these molecular sieves were characterized by XRD，N2 adsorption，NH3-TPD, Py-IR adsorption and TG techniques. The experimental results demonstrate that the structure and acidity of various molecular sieves play an important role on the reaction network of ECH isomerization, especially the pore structure. In ECH isomerization reactions, more strong/medium acid sites and enough space for reaction are required. Since MOR has 12-membered ring structure and EU-1 has 12-membered ring side pockets, they possess better reaction activity. On the whole, among these three molecular sieves, EU-1 exhibits as the optimal catalyst for ethylbenzene isomerization based on its high ECH conversation and good C8 isomerization selectivity.

Key words: ethylcyclohexane , isomerization , molecular sieve, structure characteristics , acidity