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Fine-tuning of nano-traps in a stable metal–organic framework for highly efficient removal of propyne from propylene
- Wen, Hui-Min, Li, Libo, Lin, Rui-Biao, Li, Bin, Hu, Bin, Zhou, Wei, Hu, Jun, Chen, Banglin
- Journal of materials chemistry 2018 v.6 no.16 pp. 6931-6937
- adsorption, coordination polymers, hydrogen bonding, porous media, propylene, trapping
- Despite tremendous efforts, precise control in the synthesis of porous materials with ideal nanocages for desired gas separation applications still remains a challenge. Microporous metal–organic frameworks (MOFs) have provided rich chemistry to enable precise control and design of structures, pore cavities, and functionalities at the molecular level. Here, we propose and design a microporous MOF (termed as ZJUT-1, ZJUT = Zhejiang University of Technology) with a fine-tuned nanocage, exhibiting the desired size, shape, and functionalities that are suitable for trapping a single propyne (C₃H₄) molecule. Adsorption and computational studies indicate that such optimized nanocages can not only reduce the uptake of propylene (C₃H₆), but also strengthen the C₃H₄–host interactions through multiple hydrogen-bonding between SiF₆²⁻/–NH₂ and C₃H₄ molecules. This material thus shows remarkably different C₃H₄ and C₃H₆ adsorption capacities, with the largest uptake ratio of 3.06 at 1 bar and 298 K, affording a very high selectivity (up to 70) for C₃H₄/C₃H₆ (1/99) separation. The actual breakthrough experiments demonstrate that ZJUT-1 can efficiently remove trace amounts of C₃H₄ from the important raw C₃H₄/C₃H₆ mixtures under ambient conditions with 0.19 mmol g⁻¹ C₃H₄ uptake capacity to produce 99.9995% pure C₃H₆.