物理化学学报 >> 2016, Vol. 32 >> Issue (2): 519-526.doi: 10.3866/PKU.WHXB201511243

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高硅MFI分子筛膜的合成与低温脱除膜内有机模板剂

赵淑蘅1,2,郎林1,*(),江俊飞1,2,阴秀丽1,吴创之1   

  1. 1 中国科学院广州能源研究所, 中国科学院可再生能源重点实验室, 广州 510640
    2 中国科学院大学, 北京 100049
  • 收稿日期:2015-09-24 发布日期:2016-01-30
  • 通讯作者: 郎林 E-mail:langlin@ms.giec.ac.cn
  • 基金资助:
    国家自然科学基金(51202245, 51106165);广东省自然科学基金(S2013010014896, 10251007006000000)

Synthesis and Low-Temperature Detemplation of High-Silica MFI Zeolite Membranes

Shu-Heng ZHAO1,2,Lin LANG1,*(),Jun-Fei JIANG1,2,Xiu-Li YIN1,Chuang-Zhi WU1   

  1. 1 CAS Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, P. R. China
    2 University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2015-09-24 Published:2016-01-30
  • Contact: Lin LANG E-mail:langlin@ms.giec.ac.cn
  • Supported by:
    the National Natural Science Foundation of China(51202245, 51106165);Natural Science Foundation ofGuangdong Province, China(S2013010014896, 10251007006000000)

摘要:

采用旋涂法在粗糙的α-Al2O3载体片上制备出较完备的分子筛晶种层;以四丙基氢氧化铵(TPAOH)为有机模板剂,通过调控合成液的H2O/Si摩尔比,实现了对分子筛晶体面内优先生长的调控;经过三次水热合成得到致密交联的h0h-轴取向高硅MFI分子筛膜,膜厚约为8 μm(包括~5 μm致密层和~3 μm过渡层)。采用先低温加氢裂解后低温空气氧化的两步法脱除工艺,有效脱除了分子筛膜内的有机模板剂。相比于传统高温煅烧法,该法可以避免分子筛膜因脱除模板剂而形成的较大晶间缺陷。因而采用低温两步法脱除模板剂的分子筛膜片在30 ℃时具有较好的CO2分离效果,其CO2/N2分离因子达到5.2, CO2渗透通量高达5.8 × 10-7mol·m-2·s-11·Pa-1

关键词: 高硅MFI分子筛膜, 模板剂脱除, 低温加氢裂解, 气体膜分离, 载体

Abstract:

High-silica MFI zeolite membranes supported on porous α-alumina discs were prepared by a seeded secondary growth method, using tetrapropylammonium hydroxide (TPAOH) as organic template. First, nanocrystals were deposited on rough α-Al2O3 discs by a spin-on process. Then, based on controlling the H2O/Si molar ratio of the synthetic solution, a restricting in-plane h0h-oriented growth method with an ultra-dilute precursor was designed to prepare non-defective zeolite membranes that were as thin as possible. Finally, crosslinked and dense MFI zeolite membranes were prepared after the third synthesis step, giving a membrane layer thickness of about 8 μm, including ~5 μm dense layers and ~3 μm intermediate layers. Anovel, two-step method, coupling by low-temperature hydrocracking and oxidation, is proposed for efficient removal of the template from zeolite membranes. Compared with traditional high-temperature calcination, template removal by the two-step method could eliminate the grain boundary defects formed in response to stresses induced by heat treatment. As a result, the membranes treated by the two-step detemplation method displayed a preferable CO2/N2 separation factor (about 5.2) and high CO2 permeance (5.8 × 10-7 mol·m-2·s-11·Pa-1) at 30 ℃.

Key words: High-silica MFI zeolite membrane, Template removal, Low-temperature hydrocracking, Gas permeation, Support

MSC2000: 

  • O647