Wang Jia-Xin, Xiong Shunshun, Gu Xiao-Wen, Wen Hui-Min, Zhang Xu, Chen Banglin, Li Bin, Qian Guodong
State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, 621900, China.
Angew Chem Int Ed Engl. 2025 Sep 22:e202515759. doi: 10.1002/anie.202515759.
Development of energy-efficient physisorbents for xenon/krypton (Xe/Kr) separation is highly essential to produce high-purity noble gases and control the pollution of radioactive isotopes. Porous organic materials are very promising for gas separation due to their advantages of low regeneration energy, high moisture resistance, good solution processability and easy regeneration. However, their nonpolar pore surfaces lack strong sorbate-sorbent interactions, leading to the intrinsic trade-off between Xe capacity and selectivity that severely delimit their separation efficiency. Herein, we report a strategy of designing channel-pocket ultra-micropore configuration in a threefold interpenetrated HOF (ZJU-HOF-6a) for achieving simultaneous high Xe capture and Xe/Kr separation. This channel-pocket ultra-micropore structure can provide the size-matched pore channels and cavities (4.7 and 4.4 Å) to offer strong pore confinement for highly selective binding of Xe, and also maximize the usage of pore spaces for high surface area (1113 m g) to target large Xe adsorption. ZJU-HOF-6a thus achieves a rare combination of simultaneous high Xe uptake (3.3 mmol g) and record Xe/Kr selectivity (23.5) at 298 K and 1 bar, surpassing all the reported porous organic materials. The adsorption binding of Xe and Kr was visualized by gas-loaded ZJU-HOF-6a crystal structures. Breakthrough experiments demonstrate its exceptional separation capacities for actual Xe/Kr mixtures under ambient conditions, affording the record-high dynamic selectivity (13.7) among porous organic materials.
开发用于氙/氪（Xe/Kr）分离的节能物理吸附剂对于生产高纯度稀有气体和控制放射性同位素污染至关重要。多孔有机材料因其再生能量低、防潮性高、溶液加工性好和易于再生等优点，在气体分离方面极具潜力。然而，它们的非极性孔表面缺乏强烈的吸附质 - 吸附剂相互作用，导致Xe容量和选择性之间存在内在权衡，严重限制了它们的分离效率。在此，我们报告了一种在三重互穿的HOF（ZJU - HOF - 6a）中设计通道 - 口袋超微孔结构的策略，以实现同时高效捕获Xe和分离Xe/Kr。这种通道 - 口袋超微孔结构可以提供尺寸匹配的孔道和空腔（4.7和4.4 Å），为Xe的高选择性结合提供强大的孔限制，同时最大化孔空间的利用以实现高比表面积（1113 m²/g），从而实现大量Xe的吸附。因此，ZJU - HOF - 6a在298 K和1 bar条件下实现了同时高Xe吸附量（3.3 mmol/g）和创纪录的Xe/Kr选择性（23.5）的罕见组合，超过了所有已报道的多孔有机材料。通过负载气体的ZJU - HOF - 6a晶体结构可视化了Xe和Kr的吸附结合。突破实验证明了其在环境条件下对实际Xe/Kr混合物具有出色的分离能力，在多孔有机材料中提供了创纪录的高动态选择性（13.7）。
