毛细管微通道内流动法连续合成亚微纳米分子筛

Continuous-flow Synthesis of Submicron and Nano-zeolites in Capillary Microchannel Reactor

采用毛细管式微通道反应器,研究了清液合成体系中流动法条件下亚微纳米级NaA和Silicalite-1沸石分子筛的合成,考察了合成温度、陈化时间、停留时间等条件对其粒径分布和形貌的影响.通过XRD、TEM、DLS进行表征,分析结果表明:降低合成温度,增加陈化时间和减少停留时间都能使分子筛产品的粒径变小.经优化的合成条件分别是:当合成温度为70℃、陈化时间为72h、停留时间为5.8h时,可获得平均粒径约为100nm的NaA分子筛,且晶粒均匀呈椭球形;合成温度为98℃、陈化时间为24h、停留时间为10h时,可获得平均粒径约为80nm的Silicalite-1分子筛.该方法比常规合成釜内静态法制备的沸石粒子小而均匀,且合成过程简单、连续.

Continuous synthesis of NaA and Silicalite-1 submicron and nanoparticles was prepared in a capillary microchannel reactor from clear solutions.The X-ray diffraction（XRD）,Transmission Electron Microscope（TEM） and Dynamic Light Scatter（DLS） measurements were used to investigate the effects of different synthesis parameters on the particle size distribution and morphology,including reaction temperature,aging time and residence time.It was indicated that smaller mean particle size and narrower particle size distribution of the products was obtained with lower reaction temperature,longer aging time and shorter residence time during the synthesis process.At the synthesis temperature of 343K,aging time of 72h and residence time of 5.8h,the NaA zeolite crystal with mean particle size of about 100nm was prepared.And at the synthesis temperature of 371K,aging time of 24h and residence time of 10h,the Silicalite-1 zeolite crystal with mean particle size of around 80nm was obtained.The present method offers a novel route for preparing submicro and nano zeolite particles.