Abstract: Using double-headed quaternary ammonium salt C_18-6-6Br₂ as the assistant template,the EU-1 zeolites with special morphology were synthesized with hydrothermal method and vapor phase method.The product samples were characterized by XRD,SEM,NH₃-TPD and N₂ adsorption-desorption.Besides,xylene isomerization was used as the probe reaction to evaluate their catalytic performance.Results show that the addition of the double-headed quaternary ammonium salt C_18-6-6Br₂ can effectively change the morphology of the product,especially in the case of vapor phase method.The morphology of EU-1 zeolite synthesized by adding C_18-6-6Br₂ in the steam phase shows honeycomb,and both its strong acid content and weak acid content decrease.The total specific surface area and the total pore volume increases by 83.65% and 126.72% respectively.The yield of xylene (PX),the selectivity (Y(C₈)) and the catalytic activity ([PX]/ΣX) significantly increases by 8.94%,6.44% and 6.01% respectively in the xylene isomerization reaction.

Key words: double-headed quaternary ammonium salt, EU-1 zeolites, hydrothermal method, vapor phase method, xylene isomerization