以水作为绿色溶剂在室温条件下制备出大小为500nm的[Co(Im)2]∞晶体，粒径分布比较均匀，适宜作为成膜的晶种。利用二次生长法在大孔管状α-Al2O3载体上制备致密连续的[Co(Im)2]∞膜，并考察了成膜时间、合成液浓度对成膜的影响。采用SEM，XRD和单组分气体测试对膜的形貌和气体分离性能进行表征。通过SEM显示[Co(Im)2]∞膜无缺陷，膜层厚度约为9μm。由单组分气体渗透测试可知，室温条件下H2的渗透通量达到1.1×10-8mol m-2s-1Pa-1，H2/CO2，H2/N2和H2/CH4的理想分离系数分别7.8，9.1和7.9，超过努森扩散系数。

[Co(Im)2]∞ seeds with size of 500nm were obtained in aqueous solution at near room temperature. The characterization of SEM, XRD showed that the [Co(Im)2]∞ crystals with uniform particle size distribution is suitable as seeds for the selected macroporous support. Through secondary growth method in aqueous solutions, continuous and crack-free [Co(Im)2]∞ membrane was successfully obtained on the low-cost macroporous α-Al2O3 support, exhibiting H2 permeance of 1.1×10-8mol m-2s-1Pa-1, with ideal selectivities for H2/CO2, H2/N2 and H2/CH4 ystem of 7.8, 9.1 and 7.9. Moreover, The effects of some parameters including the concentration of solution and synthesis times on the formation of [Co(Im)2]∞ membranes were investigated

[1] Owsell LC, Yaghi OM. Metal–organic frameworks: a new class of porous materials. [J]. Micropor. Mesopor. Mater., 2004, 73: 3-14.
[2] Zacher D， Shekhah O, WÖll C, et al. Thin films of metal–organic frameworks. [J]. Chem. Soc. Rev., 2009, 38(5): 1418-1429.
[3] Liu Y, Ng Z, Khan EA, et al. Synthesis of continuous MOF-5 membranes on porous α-alumina substrates. [J]. Micropor. Mesopor. Mater., 2009, 118: 296-301.
[4] Gascon J, Aguado S, Kapteijn F. et al. Manufacture of dense coatings of Cu3(BTC)2 (HKUST-1) on α-alumina [J]. Micropor. Mesopor. Mater., 2008, 113: 132-138.
[5] Venna SR, Carreon MA. et al. Highly Permeable Zeolite Imidazolate Framework-8 Membranes for CO2/CH4 Separation. [J]. J. Am. Chem. Soc., 2010, 132: 76-78.
[6] Li YS, Liang FY, Bux H. et al. Molecular Sieve Membrane: Supported Metal-Organic Framework with High Hydrogen selectivity. [J]. Angew. Chem. Int. Edit., 2010, 49: 548-55.
[7] Guerrero VV, Yoo Y, Mccarthy MC. et al. HKUST-1 membranes on porous supports using secondary growth. [J]. J, Mater, Chem., 2010, 20: 3938-3943.
[8] Yao JF, Dong DH, Li D, et al. Contra-diffusion synthesis of ZIF-8 films on a polymer substrate. [J]. Chem. Commun., 2011, 47: 2559-2561.
[9] Yoo Y, Lai Z, Jeong HK. Fabrication of MOF-5 membranes using microwave-induced rapid seeding and solvothermal secondary growth. [J]. Micropor. Mesopor. Mater., 2009, 123: 100-106.
[10] Huang A, Dou W, Caro J. Steam-stable zeolitic imidazolate framework ZIF-90 membrane with hydrogen selectivity through covalent functionalization. [J]. J. Am. Chem. Soc., 2010, 132: 15562-15564.
[11] Xie Z, Yang JH, Wang JQ. et al. Deposition of chemically modified α-Al2O3 particles for high performance ZIF-8 membrane on a macroporous tube. [J]. Chem. Commun., 2012, 48, 5977-5979.
[12] McCarthy MC, Varela V, Barnett GV, et al. Synthesis of zeolitic imidazolate framework films and membranes with controlled microstructures. [J]. Langmuir, 2010, 26: 14636-14641.
[13] Dong X, Huang K, Liu S. et al. Synthesis of zeolitic imidazolate framework-78 molecular-sieve membrane: defect formation and elimination. [J]. J. Mater. Chem., 2012, 22: 19222-19227.
[14] Guo H, Zhu GS. Qiu SL. “Twin Copper Source” Growth of Metal-Organic Framework Membrane: Cu3(BTC)2 with High Permeabil-ity and Selectivity for Recycling H2. [J]. J. Am. Chem. Soc., 2009, 131: 1646-1647.
[15] Aguado S, Nicolas CH, Moizan V, Facile synthesis of an ultramicroporous MOF tubular membrane with selectivity towards CO2. [J]. New. J. Chem., 2011, 35(1): 41-44.
[16] Pan Y, Liu Y, Zeng G. et al. Rapid synthesis of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals in an aqueous system. [J] Chem. Commun., 2011, 47: 2071-2073.
[17] Pan Y, Heryadi D, Zhou F, et al. Tuning the crystal morphology and size of zeolitic imidazolate framework-8 in aqueous solution by surfactants. [J] CrystEngComm, 2011, 13: 6937-6940.
[18] Pan Y. Lai Z. Sharp separation of C2/C3 hydrocarbon mixtures by zeolitic imidazolate framework-8 (ZIF-8) membranes synthesized in aqueous solutions. [J] Chem. Commun., 2011, 47: 10275–10277.
[19] Pan Y, Li T, Lestari G, et al. Effective separation of propylene/propane binary mixtures by ZIF-8 membranes. [J] J. Membrane Sci., 2012 390-391: 93-98.
[20] Tian YQ, Cai CX, Ren XM, et al. The Silica-Like Extended Polymorphism of Cobalt(ii) Imidazolate Three-Dimensional Frameworks: X-ray Single-Crystal Structures and Magnetic Properties. [J]. Chem. Eur. J. 2003, 9: 5673-5685
[21] Venna S, Jasinski J, Carreon M. Structural Evolution of Zeolitic Imidazolate Framework-8. [J] J. Am. Chem. Soc. 2010, 132: 18030–18033.