Zhang Zhaoqiang, Peh Shing Bo, Krishna Rajamani, Kang Chengjun, Chai Kungang, Wang Yuxiang, Shi Dongchen, Zhao Dan
Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore, Singapore.
Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098, XH, Amsterdam, The Netherlands.
Angew Chem Int Ed Engl. 2021 Jul 26;60(31):17198-17204. doi: 10.1002/anie.202106769. Epub 2021 Jun 29.
Isolation of CO from acetylene (C H ) via CO -selective sorbents is an energy-efficient technology for C H purification, but a strategic challenge due to their similar physicochemical properties. There is still no specific methodology for constructing sorbents that preferentially trap CO over C H . We report an effective strategy to construct optimal pore chemistry in a Ce -based ultramicroporous metal-organic framework Ce -MIL-140-4F, based on charge-transfer effects, for efficient inverse CO /C H separation. The ligand-to-metal cluster charge transfer is facilitated by Ce with low-lying unoccupied 4f orbitals and electron-withdrawing F atoms functionalized tetrafluoroterephthalate, affording a perfect pore environment to match CO . The exceptional CO uptake (151.7 cm cm ) along with remarkable separation selectivities (above 40) set a new benchmark for inverse CO /C H separation, which is verified via simulated and experimental breakthrough experiments. The unique CO recognition mechanism is further unveiled by in situ powder X-ray diffraction experiments, Fourier-transform infrared spectroscopy measurements, and molecular calculations.
通过CO选择性吸附剂从乙炔（C₂H₂）中分离CO是一种用于C₂H₂纯化的节能技术，但由于它们相似的物理化学性质，这是一个具有挑战性的难题。目前仍然没有构建优先捕获CO而非C₂H₂的吸附剂的具体方法。我们报道了一种基于电荷转移效应，在Ce基金属有机超微孔框架Ce-MIL-140-4F中构建最佳孔化学的有效策略，用于高效的CO₂/C₂H₂逆分离。具有低未占4f轨道的Ce和功能化四氟对苯二甲酸酯的吸电子F原子促进了配体到金属簇的电荷转移，提供了与CO₂相匹配的完美孔环境。出色的CO₂吸附量（151.7 cm³ cm⁻³）以及显著的分离选择性（高于40）为CO₂/C₂H₂逆分离设定了新的基准，这通过模拟和实验突破实验得到了验证。原位粉末X射线衍射实验、傅里叶变换红外光谱测量和分子计算进一步揭示了独特的CO₂识别机制。
