Zhang Jingyao, Liu Zewei, Liu Hongbin, Xu Feng, Li Zhong, Wang Xun
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China.
School of Environment and Chemical Engineering, Foshan University, Foshan 528225, China.
ACS Omega. 2022 Feb 24;7(9):7648-7654. doi: 10.1021/acsomega.1c06309. eCollection 2022 Mar 8.
Development of an ethane-selective adsorbent to separate ethane from ethylene is a challenging issue with great significance for ethylene purification. The adsorptive separation technique based on physical adsorption holds a great promise to address this issue. Herein, we report a robust ethane-selective metal-organic framework, Ni(BODC)(TED), and investigate its separation performance on CH/CH. The as-synthesized Ni(BODC)(TED) exhibits excellent water vapor stability and high capacity of CH molecules with an uptake of 3.36 mmol/g at 298 K and 100 kPa, higher than those of many adsorbents reported in recent years. Its CH/CH selectivity predicted by the ideal adsorbed solution theory (IAST) model reaches 1.79. A molecular simulation is applied to unveil the preferential adsorption mechanism of ethane. Calculation shows that five strong C-H···H interactions are formed between CH and the framework of Ni(BODC)(TED), and the isosteric heat of ethane on Ni(BODC)(TED) is 27.02 kJ/mol, higher than that of ethylene, resulting in preferential adsorption of ethane. Ni(BODC)(TED) would become a promising member of the family of ethane-selective materials for the industrial separation of ethane from ethylene.
开发一种用于从乙烯中分离乙烷的乙烷选择性吸附剂是一个具有挑战性的问题，对乙烯纯化具有重要意义。基于物理吸附的吸附分离技术有望解决这一问题。在此，我们报道了一种坚固的乙烷选择性金属有机框架Ni(BODC)(TED)，并研究了其对CH/CH的分离性能。合成的Ni(BODC)(TED)表现出优异的水蒸气稳定性和对CH分子的高吸附容量，在298 K和100 kPa下的吸附量为3.36 mmol/g，高于近年来报道的许多吸附剂。通过理想吸附溶液理论（IAST）模型预测，其CH/CH选择性达到1.79。采用分子模拟揭示乙烷的优先吸附机制。计算表明，CH与Ni(BODC)(TED)骨架之间形成了五个强C-H···H相互作用，乙烷在Ni(BODC)(TED)上的等量吸附热为27.02 kJ/mol，高于乙烯，导致乙烷优先吸附。Ni(BODC)(TED)有望成为从乙烯中工业分离乙烷的乙烷选择性材料家族中的一个有前途的成员。
