以TPABr为模板剂的ZSM-5分子筛膜的合成与表征

以四丙基溴化铵(TPABr)为模板剂,直接在多孔的α-A1_2O_3陶瓷管外表面,经过重复合成制得了渗透通量较大的ZSM-5沸石分子筛膜。以合成ZSM-5沸石的DTA/TGA分析结果为依据,确定了去除ZSM-5沸石膜中模板剂的热处理制度。用X R D和S E M对Z S M-5沸石分子筛膜进行了表征,膜的分离因子用单一的氢气和氮气的渗透通量的比值表示。X RD分析表明陶瓷基质表面的膜层是ZSM-5沸石晶相,S E M结果显示合成的沸石膜层晶体相互交连,形成一种连续的多晶层,厚度约10μm。H_2、N_2对分子筛膜的气体渗透表明,合成的ZSM-5沸石膜的H_2/N_2理想分离因子为2.87。

THE HYDROTHERMAL SYNTHESIS AND CHARACTERIZATION OF ZSM-5 ZEOLITE MEMBRANES USING TPABr AS A TEMPLATE

ZSM-5 zeolite films were prepared on the outer surface of porous -alumina ceramic tube by hydrothermal synthesis using tetrapropylammonium bromide (TPABr) as a template and the preparation conditions were discussed. The greater permeation flux of ZSM-5 zeolite membrane has been synthesized through repeating composition .On the basis of the analysis result of DTA/TGA of ZSM-5 zeolite, the heat treatment system of ZSM-5 zeolite membrane to exclude templates has been determined. The crystal of ZSM-5 zeolite film was characterized by XRD and SEM. The separation factor of this film was obtained in termsof the ratio of single hydrogen and nitrogen gas permeation flux. X-ray diffraction confirmed the thin layer on the surface of ceramic tube to be ZSM-5 crystalline phase, and SEM showed that individual ZSM-5 crystals had grown together in three dimensions and formed a continuous polycrystalline layer with thickness of about 10um. The ideal selectivity for H2 over N2 was 2.87 of zeolite membrane.