化学学报 ›› 2003, Vol. 61 ›› Issue (12): 1944-1948. 上一篇    下一篇

研究论文

添加成膜促进剂合成致密ZSM-5分子筛膜

程志林;晁自胜;方维平;林海强;方惠霖   

  1. 华东师范大学化学系;厦门大学化学系
  • 发布日期:2003-12-15

Synthesis of Compact ZSM-5 Zeolite Membrane by Adding the Promoter NaCl

Cheng Zhilin;Chao Zhisheng;Fang Weiping;Lin Haiqiang;Wan Huilin   

  1. Key Laboratory of Green Chemistry and Chemical Process Greening, Department of Chemistry, East China Normal University;State Key Laboratory for Physical Chemistry of Solid Surface, Department of Chemistry, Xiamen University
  • Published:2003-12-15

报道了一种添加氯化钠低温条件下合成出具有纳米尺寸的ZSM-5分子筛,并以 其为晶种预吸附在多孔氧化铝载体上,再通过添加成膜促进剂氯化钠二次水热合成 制备出高度致密ZSM-5分子筛膜的新方法。通过考察添加的钠离子浓度对成膜的影 响,认为在一定浓度范围内钠离子能够促进成膜。SEM结果也验证了这一结论,分 子筛膜主要是由孪生聚晶分子筛组成。渗透结果显示,当添加量为x = 100 (Al_2O_3:84SiO_2:10Na_2O:15TPABr:3500H_2O)时,在室温和0.1 MPa的条件下, H_2/C_3的理想选择性最大值23.7,温度提高到200 ℃时的选择性下降为9.4,但仍 然高于努森扩散值(4.69),表面该膜具有高度的完整性。

关键词: 分子筛, 纳米相材料, ZSM-5, 气体分离, 吸附, 氧化铝, 氯化钠, 水热反应

The compact ZSM-5 membranes was synthesized on porous alumina substrates by pre-coating nanosized ZSM-5 seeds and then employing the twice hydrotheiTnal synthesis with adding the promoter NaCI. Effect of Na~+ concentration on the formation of membrane was investigated in this work, indicating that adding a certain mount of NaCI can boost the growth of zeolite crystals on the substrates, thus forming the compact membrane consisted of highly intergrown crystals. The separating performance of zeolite membranes indicated that using a mixture with a composition of A1_2O_3: 84SiO_2: 10Na_2O : 100NaCl: 15TPABr: 3500H_2O as synthesis gel, the ideal selectivity of H2/C3H8 could reach a maximum value of 23.7 at room temperature and pressure difference of 0.1 MPa, and the permselectivity decreased to 9.4 at testing temperature of 200 ℃ , which is still higher than the corresponding Knudsen diffusion value (4.69), suggesting that the membrane synthesized by this method was defect-free.

Key words: MOLECULAR SIEVE, NANOPHASE MATERIALS, ZSM-5, GAS SEPARATION, ADSORPTION, ALUMINIUM OXIDE, SODIUM CHLORIDE, HYDRO-THERMAL REACTION

中图分类号: