Yang Liping, Liu Hanbang, Xing Jiacheng, Yuan Danhua, Xu Yunpeng, Liu Zhongmin
National Engineering Laboratory for Methanol to Olefins, Dalian National Laboratory for Clean Energy, Dalian Institute, of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Chemistry. 2021 Apr 7;27(20):6187-6190. doi: 10.1002/chem.202100008. Epub 2021 Mar 5.
Xylene isomer separation is considered one of the seven separation challenges that changed the world. In addition, the high-energy demand of xylene separation highlights the need for efficient novel adsorbents. Herein, the liquid-phase separation potential of the anion-pillared hybrid material SIFSIX-1-Cu was studied for preferential adsorption of o-xylene and m-xylene over p-xylene, which was inspired by a previous complexation crystallization method for separating m-xylene. We report detailed experimental liquid-phase adsorption experiments, yielding selectivities of 3.0 for o-xylene versus p-xylene and 2.6 for m-xylene versus p-xylene. Our theoretical calculations thus provide a reasonable explanation that the xylene adsorption selectivity is attributed to the C-H⋅⋅⋅F interaction, and the host-guest interaction order agrees with the adsorption priority: o-xylene > m-xylene > p-xylene.
二甲苯异构体分离被认为是改变世界的七大分离挑战之一。此外，二甲苯分离的高能量需求凸显了对高效新型吸附剂的需求。在此，受先前用于分离间二甲苯的络合结晶方法的启发，研究了阴离子柱撑杂化材料SIFSIX-1-Cu的液相分离潜力，以实现邻二甲苯和间二甲苯相对于对二甲苯的优先吸附。我们报告了详细的实验液相吸附实验，邻二甲苯相对于对二甲苯的选择性为3.0，间二甲苯相对于对二甲苯的选择性为2.6。我们的理论计算因此提供了一个合理的解释，即二甲苯吸附选择性归因于C-H⋅⋅⋅F相互作用，且主客体相互作用顺序与吸附优先级一致：邻二甲苯>间二甲苯>对二甲苯。
