动态水热合成b轴取向MFI型分子筛膜

Dynamic Hydrothermal Synthesis of a b-Oriented MFI Zeolite Film

在旋转烘箱中采用动态水热法,在不锈钢片支撑体上合成了连续的b轴取向MFI型分子筛膜,并运用扫描电镜和X射线衍射考察了合成釜转速、晶化温度和晶化时间对所得分子筛膜性能的影响.与静态水热法相比,动态水热合成过程中合成液的温差和浓度差大大降低,且合成液持续冲刷支撑体表面,使得动态法具有合成时间短、取向性好和分子筛颗粒粒径分布均一的优点.

Continuous b-oriented MFI zeolite films were prepared on stainless steel substrates by dynamic hydrothermal synthesis using a rotating convection oven. The influences of rotation speed,crystallization temperature and crystallization time were studied. X-ray diffraction was used to identify the orientation of the zeolite films. Compared with the static method,a shorter synthesis time,a more uniform particle size distribution and better film orientation were observed for the dynamic method,and this is attributed to the low concentration and thermal gradients that exist in the bulk solution and to the washing action of the bulk solution toward the substrate surface.