摘要
以聚乙二醇为介孔导向剂,通过凝胶转化制备了介孔ZSM-5沸石。研究表明,在TPA＋/Si O2=0.1时经过9~15 h溶剂挥发制得的凝胶,在160℃处理24 h可得到介孔ZSM-5沸石;挥发时间太短或太长会得到纯的ZSM-5沸石或介孔材料,说明在凝胶的制备过程中,通过控制溶剂的挥发程度,既可为沸石生长过程提供所需的水分,又能避免沸石晶体形成过程中无定型相的产生,从而在较低的TPA＋浓度下获得介孔ZSM-5沸石。与传统的ZSM-5沸石相比,利用该方法制备的介孔ZSM-5沸石不仅具有微孔/介孔多级孔结构,同时具有沸石材料较强的酸性、较高的水热稳定性和择形催化性能,使其在苯甲醛与正丁醇的大分子醇醛缩聚反应中能有效地克服传统沸石孔径限制的缺点,收率高达42.4%。
A simple strategy for synthesizing mesoporous zeolite ZSM-5 via gel conversion was successfully developed with polyethyleneglycol as mesopore directing agent. It is revealed that the gel obtained after 9–15 h evaporation of solvents could be transferred into mesoporous ZSM-5 zeolite after treatment at 160℃ for 24 h. However, pure ZSM-5 zeolite or mesoporous silica was achieved with too short or too long evaporation periods. The results indicate that the gelation process through solvent evaporation controls the hierarchical structure formation kinetically, which not only provides an appropriate amount of water for zeolite crystallization, but also prevents the phase-separation between zeolite and amorphous phases. Due to the introduction of the mesoporosity of several tens of nanometers in size, this hierarchical micro/mesostructured zeolite exhibits enhanced catalytic activities in the large molecules involved reactions, including aldol condensation of benzaldehyde with n-butyl alcohol and Pechmann reaction of resorcinol with ethylacetoacetate.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第11期1148-1154,共7页
Journal of Inorganic Materials
关键词
介孔沸石
聚乙二醇
凝胶转化
一锅法
mesoporous zeolite
polyethyleneglycol
gel conversion
one-pot
作者简介
安建国（1989-），男，硕士研究生．E—mail：Caesar_An@163．com
通讯作者：李永生，教授．E-mail：ysli@ecust．edu．cn
