合成条件对硅基介孔分子筛结构的影响

Influence of Synthesis Parameters upon the Textural and Structural Properties of Silica-based Mesoporous Molecular Sieves

采用水热法制备硅基介孔分子筛材料,较系统地考察了合成条件对其结构的影响,并利用N2吸附、透射电镜(TEM)等手段进行了表征.研究发现,随着晶化温度的升高,硅基介孔分子筛材料的平均孔径在逐渐增大,而比表面先增大后减小,100℃晶化时比表面最大(905.60 m2/g);随着晶化时间的延长,样品的平均孔径先增大后减小,比表面却正好相反,晶化1 d时比表面是905.60 m2/g,晶化3 d时比表面降为788.91m2/g;随着焙烧温度的升高比表面和孔径均减小,表明高温下焙烧易导致介孔结构的塌陷.

Silica-based mesoporous molecular sieves was synthesized by hydrothermal method and characterized by N2 sorption and TEM. The results showed that the pore size of the prepared material increased with the increase of crystallization temperature under the same condition. It was also found that pore size became larger with the increase of crystallization time and the largest one was 4.54 nm when it was crystallized for three days. The opposite behavior was observed for the average specific surface area. Both the pore size and surface area decreased with the increase of calcination temperature due to the destruction of the mesoporous structure.