Parallel pathways for transport in ZSM-5 zeolite membranes
Parallel pathways for transport in ZSM-5 zeolite membranes
复制标题
ZSM-5 沸石膜中的平行传输途径
DOI：
10.1021/cm980484m
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发表时间：
1998
影响因子：
8.6
通讯作者：
R. Noble
中科院分区：
文献类型：
--
作者：
Xiao Lin;J. Falconer;R. Noble
通过表征沸石合成模板剂通过在逐渐升高的温度下煅烧4 h或在573 K下煅烧更长时间而去除时的气体渗透性能，研究了ZSM-5沸石膜制备过程中的变化。沸石和晶间孔似乎都存在;非沸石孔较大并且具有较低的理想选择性，但是这些孔足够小和/或以足够低的浓度，使得对于最终膜获得高的理想选择性和混合物选择性。四丙基氢氧化铵模板首先从较大的晶间孔中除去，因此理想的选择性随煅烧温度或时间显著变化。N2/SF6理想选择性也取决于测量方法;它们对于跨膜的压降比当使用吹扫气体时更高，显然是因为SF6的驱动力的变化，SF6比N2吸附更强。渗透性继续增加，因为膜……
Changes in ZSM-5 zeolite membranes during preparation were studied by characterizing the gas permeation properties as the zeolite synthesis template was removed by calcination for 4 h at progressively higher temperatures or for longer times at 573 K. Both zeolite and intercrystalline pores appear to be present; the nonzeolitic pores are larger and have lower ideal selectivities, but these pores are small enough and/or in low enough concentrations that high ideal and mixture selectivities are obtained for the final membranes. The tetrapropylammonium hydroxide template is removed from the larger intercrystalline pores first, and thus ideal selectivities changed significantly with calcination temperature or time. The N2/SF6 ideal selectivities also depend on the measurement method; they were higher for a pressure drop across the membrane than when a sweep gas was used, apparently because of the change in driving force for SF6, which adsorbs more strongly than N2. Permeances continue to increase as membranes ...