Membrane-based separations can improve energy efficiency and reduce the environmental impacts associated with traditional approaches. Nevertheless, many challenges must be overcome to design membranes that can replace conventional gas separation processes. Here, we report on the incorporation of engineered submicrometre-sized metal–organic framework (MOF) crystals into polymers to form hybrid materials that successfully translate the excellent molecular sieving properties of face-centred cubic (fcu)-MOFs into the resultant membranes. We demonstrate, simultaneously, exceptionally enhanced separation performance in hybrid membranes for two challenging and economically important applications: the removal of CO₂ and H₂S from natural gas and the separation of butane isomers. Notably, the membrane molecular sieving properties demonstrate that the deliberately regulated and contracted MOF pore-aperture size can discriminate between molecular pairs. The improved performance results from precise control of the linkers delimiting the triangular window, which is the sole entrance to the fcu-MOF pore. This rational-design hybrid approach provides a general toolbox for enhancing the transport properties of advanced membranes bearing molecular sieve fillers with sub-nanometre-sized pore-apertures.

基于膜的分离可以提高能源效率，并减少与传统方法相关的环境影响。然而，在设计可替代常规气体分离工艺的膜时必须克服许多挑战。在这里，我们报道了将工程化的亚微米级金属-有机骨架（MOF）晶体掺入聚合物中以形成杂化材料的过程，该杂化材料成功地将面心立方（fcu）-MOF的出色分子筛分特性转化为最终的膜。同时，我们证明了混合膜在两种具有挑战性且经济上重要的应用中的分离性能得到了极大提高：去除CO ₂和H ₂从天然气中分离出S和丁烷异构体。值得注意的是，膜分子筛特性表明，有意调节和收缩的MOF孔径大小可以区分分子对。改进的性能来自对连接器的精确控制，该连接器界定了三角形窗口，而三角形窗口是fcu -MOF孔的唯一入口。这种合理设计的混合方法为增强带有亚纳米级孔径的分子筛填料的先进膜的传输性能提供了一个通用的工具箱。