Flexible metal–organic framework (MOF) compounds can exhibit very pronounced structural changes, which may be favorable for gas storage and gas separation applications. The noble gases xenon and krypton are increasingly important for both research and applications. Therefore, separation approaches with lower energy consumption are of great interest. In the present paper, the adsorption of pure xenon and krypton as well as their mixture by the flexible gate pressure MOFs is investigated using in situ high-pressure ¹²⁹Xe NMR spectroscopy and volumetric gas adsorption in combination with density-functional theory (DFT) calculations. The chosen model MOF compound DUT-8(Ni) can be synthesized as a flexible or rigid structure by tuning the crystallite size. This allows us to discriminate possible effects exerted by the framework flexibility from influences of structure and composition.

中文翻译：

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氙、氪及其混合物在柔性金属有机框架DUT-8(Ni)上的吸附

柔性金属有机骨架（MOF）化合物可以表现出非常明显的结构变化，这可能有利于气体储存和气体分离应用。稀有气体氙和氪对于研究和应用越来越重要。因此，能耗较低的分离方法备受关注。本文利用原位高压¹²⁹ Xe NMR 光谱和体积气体吸附结合密度泛函理论 (DFT) 计算，研究了柔性门压 MOF 对纯氙和氪及其混合物的吸附。通过调整微晶尺寸，所选模型 MOF 化合物 DUT-8(Ni) 可以合成为柔性或刚性结构。这使我们能够区分框架灵活性可能产生的影响与结构和组成的影响。