Tailoring the separation properties of flexible metal-organic frameworks using mechanical pressure
Tailoring the separation properties of flexible metal-organic frameworks using mechanical pressure
复制标题
DOI：
10.1038/s41467-020-15036-y
复制
发表时间：
2020-03-05
影响因子：
16.6
通讯作者：
Llewellyn, Philip L.
中科院分区：
文献类型：
--
作者：
Chanut, Nicolas;Ghoufi, Aziz;Llewellyn, Philip L.
金属有机骨架材料由于其可调节的物理和化学性质而被广泛应用于化学混合物的分离。然而，虽然目前投入了大量精力来开发用于给定分离的新吸附剂，但理想的情况将涉及用于多种分离的单一吸附剂。表现出骨架柔性的多孔材料提供了调节这些性质的独特机会，因为可以通过施加外部刺激来控制孔的大小和形状。在这里，我们建立了一个概念验证的分子筛分离的物种具有相似的大小（CO2/N-2和CO2/CH4），通过精确的机械控制的孔径在一个灵活的金属有机框架。除了对所考虑的气体混合物的无限选择性外，该材料在释放外部机械约束时显示出优异的再生能力。这种策略，结合外部刺激施加到一个结构兼容的吸附剂，提供了一个有前途的途径，解决一些最具挑战性的气体分离。分离具有相似物理和化学性质的气体可能需要大量能源，而基于吸附的技术可以提供能耗较低的替代方案。在这里，作者展示了用于气体分离的柔性金属有机框架中的孔径大小的机械控制。
Metal-organic frameworks are widely considered for the separation of chemical mixtures due to their adjustable physical and chemical properties. However, while much effort is currently devoted to developing new adsorbents for a given separation, an ideal scenario would involve a single adsorbent for multiple separations. Porous materials exhibiting framework flexibility offer unique opportunities to tune these properties since the pore size and shape can be controlled by the application of external stimuli. Here, we establish a proof-of-concept for the molecular sieving separation of species with similar sizes (CO2/N-2 and CO2/CH4), via precise mechanical control of the pore size aperture in a flexible metal-organic framework. Besides its infinite selectivity for the considered gas mixtures, this material shows excellent regeneration capability when releasing the external mechanical constraint. This strategy, combining an external stimulus applied to a structurally compliant adsorbent, offers a promising avenue for addressing some of the most challenging gas separations. Separation of gasses with similar physical and chemical properties can be energy demanding, and adsorption-based technologies may provide alternatives with lower energy consumption. Here, the authors show mechanical control of pore size aperture in flexible metal-organic frameworks for separation of gasses.