Zhang Xin, Zhao Yan-Long, Li Xiang-Yu, Bai Xuefeng, Chen Qiancheng, Li Jian-Rong
Beijing Key Laboratory for Green Catalysis and Separation and Department of Chemical Engineering, College of Materials Science & Engineering, Beijing University of Technology, Beijing 100124, PR China.
J Am Chem Soc. 2024 Jul 17;146(28):19303-19309. doi: 10.1021/jacs.4c05075. Epub 2024 Jul 6.
Sulfur hexafluoride (SF) is extensively employed in the power industry. However, its emissions significantly contribute to the greenhouse effect. The direct recovery of high purity SF from industrial waste gases would benefit its sustainable use, yet this represents a considerable challenge. Herein, we report the enrichment of SF from SF/N mixtures via adsorptive separation in a stable Co(II)-pyrazolate MOF BUT-53 (BUT: Beijing University of Technology), which features dynamic molecular traps. BUT-53 exhibits an excellent SF adsorption uptake of 2.82 mmol/g at 0.1 bar and 298 K, as well as an unprecedented SF/N (10:90) selectivity of 2485. Besides, the remarkable SF/N selectivity of BUT-53 enables recovery of high purity (>99.9%) SF from a low concentration (10%) mixture through a breakthrough experiment. The excellent SF/N separation efficiency was also well maintained under humid conditions (RH = 90%) over multiple cycles. Molecular simulation, single-crystal diffraction, and adsorption kinetics studies elucidate the associated adsorption mechanism and water tolerance.
六氟化硫（SF₆）在电力行业中被广泛应用。然而，其排放对温室效应有显著影响。从工业废气中直接回收高纯度的SF₆将有利于其可持续利用，但这是一项颇具挑战的任务。在此，我们报道了在具有动态分子陷阱的稳定钴（II）-吡唑啉酸金属有机框架材料BUT-53（BUT：北京工业大学）中，通过吸附分离从SF₆/N₂混合物中富集SF₆。BUT-53在0.1巴和298 K下对SF₆的吸附量高达2.82 mmol/g，并且对SF₆/N₂（10:90）具有前所未有的2485的选择性。此外，BUT-53对SF₆/N₂的显著选择性使得通过突破实验能够从低浓度（10%）混合物中回收高纯度（>99.9%）的SF₆。在潮湿条件（相对湿度 = 90%）下经过多个循环，BUT-53对SF₆/N₂的优异分离效率也能得到很好的保持。分子模拟、单晶衍射和吸附动力学研究阐明了相关的吸附机理和耐水性。
