蒸汽相法辅助碳模板合成介孔EU-1分子筛

摘要

将蔗糖、硅源与铝源混合成凝胶,在170 ℃下部分碳化(MI)或者在无氧环境下400 ℃高温碳化(MII)两种方法原位制备碳硅铝复合物,然后采用蒸汽相法辅助合成多级孔 EU-1分子筛.研究表明:MI、MII 均可以有效提高样品的外表面积和介孔孔容,且当m(蔗糖)/m(SiO2)为定值时,MII 的介孔化能力优于MI.MI、MII 合成的样品保持一致的规律,即随着m(蔗糖)/m(SiO2)的增多,样品的结晶度逐渐降低,外表面积和介孔孔容逐渐增大,酸量明显减小.多级孔 EU-1分子筛有利于扩散,有利于提高分子筛的二甲苯异构化催化性能,其催化活性从22.99%提升到23.92%,C8芳烃选择性从89.52%提升到91.12%.%The synthetic gel was prepared by mixing sucrose,silicon and aluminum,and then partially carbonized at 170 ℃ in air(MI)or carbonized at 400 ℃ in oxygen-free environment (MII)to obtain carbon-silicon-aluminum compound.The vapor phase method was adopted to synthesize hierarchical EU-1 zeolite.The research results showed that MI and MII can effectively improve the surface area and the pore volume of mesopores.When the m(sucrose)/m(SiO2)was a fixed value,the mesoporous capacity of MII was better than that of MI.The synthetic samples by MI and MII maintain a consistent rule:with m(sucrose)/m(SiO2)increasing,the crystallinity of the samples decreases gradually;the surface area and pore volume increase little by little;the amount of weak acid and strong acid decreases obviously.The hierarchical EU-1 zeolite is favora-ble for the diffusion and improved catalytic performance for xylene isomerization,with the cata-lytic activity increasing from 22.99% to 23.92%,C8 aromatic hydrocarbon selectivity increasing from 89.52% to 91.12%.