低模板剂法合成Silicalite-1沸石膜及其气体渗透性能研究

Preparation and gas permeance separation property of silicalite-1 zeolite membrane with low-template method

在较低的模板剂浓度下，采用二次生长法在大孔（孔径约4～6μm）α-Al2O3载体上合成Silicalite-1沸石膜，并采用X射线衍射法、扫描电子显微镜及不同温度下单组分气体渗透实验对所合成的沸石膜进行表征．结果表明，合成的是典型的Silicalite-1沸石膜，无其他杂质形成；制备的沸石膜连续、互生、致密，没有明显的缺陷．在40℃下H2的渗透速率为4．47×10^-7mol／（m^2·s·Pa），H2／SF6的理想分离系数44，远高于其Knudsen扩散系数8．54．在40～200℃之间，H2／SF6的理想分离系数曲线呈V型，H2的渗透速率几乎不变，N2的渗透速率随温度升高略下降。

Silicalite- 1 zeolite membrane was prepared on macroporous support （pore size of 4--6/lm） by secondary growth method with low - template. XRD, SEM and single gas permeability tests as a function of tem- perature were used to characterize assynthesized zeolite membrane. The results showed that the prepared membrane was typical zeolite silicalite - 1, continuous, compact and dense and no obvious defects. The perme- ability of H2 was 4.47 × 10^- 7 mol/（m2·s·Pa） and the ideal selectivity of H2/SF6 reached to 44 at 40℃. Moreover, the idea selectivity of H2/SF6 which was larger than its Knudsen ratio of 8.54. With the increase in the temperature （from 40 ℃to 200℃ ）, the shape of idea selectivity curve of H2/SF6 was V type and the permeability of H2 was nearly constant, while the permeability of N2 decreased little.