Membranes with ultrahigh permeance and practical selectivity could greatly decrease the cost of difficult industrial gas separations, such as CH₄/N₂ separation. Advanced membranes made from porous materials, such as metal–organic frameworks, can achieve a good gas separation performance, although they are typically formed on support layers or mixed with polymeric matrices, placing limitations on gas permeance. Here an amorphous glass foam, a_gfZIF-62, wherein a, g and f denote amorphous, glass and foam, respectively, was synthesized by a polymer-thermal-decomposition-assisted melting strategy, starting from a crystalline zeolitic imidazolate framework, ZIF-62. The thermal decomposition of incorporated low-molecular-weight polyethyleneimine evolves CO₂, NH₃ and H₂O gases, creating a large number and variety of pores. This greatly increases pore interconnectivity but maintains the crystalline ZIF-62 ultramicropores, allowing ultrahigh gas permeance and good selectivity. A self-supported circular a_gfZIF-62 with a thickness of 200–330 µm and area of 8.55 cm² was used for membrane separation. The membranes perform well, showing a CH₄ permeance of 30,000–50,000 gas permeance units, approximately two orders of magnitude higher than that of other reported membranes, with good CH₄/N₂ selectivity (4–6).

具有超高渗透性和实用选择性的膜可以大大降低困难的工业气体分离的成本，例如CH ₄ /N ₂分离。由金属有机框架等多孔材料制成的先进膜可以实现良好的气体分离性能，尽管它们通常形成在支撑层上或与聚合物基质混合，从而限制了气体渗透性。这里无定形玻璃泡沫，_gf ZIF-62，其中a、g和f分别表示无定形、玻璃和泡沫，是通过聚合物热分解辅助熔融策略从结晶沸石咪唑酯骨架ZIF开始合成的-62。掺入的低分子量聚乙烯亚胺的热分解放出CO₂、NH ₃和H ₂ O气体，产生大量且多样的孔隙。这极大地增加了孔隙的连通性，同时保留了结晶 ZIF-62 超微孔，从而实现超高的气体渗透性和良好的选择性。使用厚度为 200-330 µm、面积为 8.55 cm ²的自支撑圆形 a _gf ZIF-62进行膜分离。该膜性能良好，显示出 30,000–50,000 个气体渗透单位的 CH ₄渗透性，比其他报道的膜高出大约两个数量级，并具有良好的 CH ₄ /N ₂选择性 (4–6)。