Separating carbon dioxide from fuel gases like hydrocarbons by physical adsorbents is industrially important and more energy-efficient than traditional liquid extraction or cryogenic distillation methods. It is very important while very challenging to develop CO₂-selective adsorbents, considering CO₂ is less polarizable than light hydrocarbon molecules, particularly those simultaneously with almost identical molecular dimensions and physical properties, such as acetylene. Herein, an ultramicroporous metal–organic framework constructed from copper(II) and 5-fluoropyrimidin-2-olate, termed Cu-F-pymo, is carefully studied under different activations for inverse separation of CO₂ from C₂H₂. The partially desolvated Cu-F-pymo can exclusively capture CO₂ over C₂H₂ with very high selectivity exceeding 10⁵ under ambient conditions, the highest ever reported. Sorption experiments and modeling studies reveal that such molecular sieving effect is attributed to the suppression of C₂H₂ adsorption from the blockage of the preferential sites for C₂H₂ by residual water molecules. The inverse separation is further confirmed by column breakthrough studies given that highly pure acetylene (>99.9%) can be directly harvested from the gas mixture. Cu-F-pymo also shows remarkable stability under harsh conditions.

中文翻译：

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超微孔金属-有机骨架中乙炔对二氧化碳的高选择性吸附

通过物理吸附剂从碳氢化合物等燃料气体中分离二氧化碳在工业上很重要，而且比传统的液体萃取或低温蒸馏方法更节能。开发 CO ₂选择性吸附剂非常重要，同时也非常具有挑战性，因为 CO ₂的极化性低于轻烃分子，尤其是那些同时具有几乎相同分子尺寸和物理性质的分子，例如乙炔。在本文中，由铜构成的ultramicroporous金属-有机骨架（II）和5-氟丙-2-醇，称为的Cu-F-pymo，小心地在不同的激活研究了CO的逆分离₂选自C ₂ ħ ₂. 部分去溶剂化的Cu-F-pymo可以在环境条件下以超过10 ^{5 的}非常高的选择性专门捕获CO _{2 而}不是C ₂ H ₂，这是有史以来报道的最高。吸附实验和建模研究表明，这种分子筛分效应归因于残余水分子对 C ₂ H ₂优先位点的阻塞，从而抑制了 C ₂ H ₂吸附。鉴于可以直接从气体混合物中收集高纯度乙炔 (>99.9%)，色谱柱突破性研究进一步证实了反向分离。Cu-F-pymo 在恶劣条件下也表现出非凡的稳定性。