Cheng Hongtao, Wang Qian, Ding Min, Gao Yajun, Xue Dongxu, Bai Junfeng
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710062, PR China.
Dalton Trans. 2021 Apr 14;50(14):4840-4847. doi: 10.1039/d0dt04142d. Epub 2021 Mar 19.
Modifying VNU-18 (a MOF with a partial cone-sql layer pillared by the chains of pillars decorated with OH) by substitution of OH with Cl, a new isoreticular structure, [Cu(L)·(Cl)·HO·4DMF]·4DMF·6(HO) (SNNU-Bai67, SNNU-Bai = Shaanxi Normal University Bai's group), has been successfully synthesized. Furthermore, we deeply investigated the selective C2 hydrocarbon separation properties of SNNU-Bai67 and VNU-18 by single-component gas adsorption experiments, breakthrough experiments and simulation studies. They exhibit highly selective adsorption for C2 hydrocarbons over CH compared to many reported MOFs for the separation of C2 hydrocarbons from CH, due to the suitable pore sizes of the partial corn sql-layer built from the isophthalic acid analogy and Cu-paddlewheel units. Interestingly, with the counterion of OH in VNU-18 tuned by Cl in SNNU-Bai67, the adsorption uptake values of C2 hydrocarbons were apparently improved by 15.0% for CH, 20.4% for CH and 25.3% for CH, respectively, while the IAST selectivities of C2 hydrocarbons/CH were still nearly the same, which may be because the synergistic effect of interactions of HO, HN/C, HC, ππ or HC between the gas molecules and the framework is enhanced by the weaker polarity of Cl decorating the framework.
通过用 Cl 取代 OH 对 VNU - 18（一种具有部分锥形 sql 层的金属有机框架，由装饰有 OH 的支柱链支撑）进行改性，成功合成了一种新的同构结构[Cu(L)·(Cl)·H₂O·4DMF]·4DMF·6(H₂O)（SNNU - Bai67，SNNU - Bai = 陕西师范大学白氏团队）。此外，我们通过单组分气体吸附实验、突破实验和模拟研究深入研究了 SNNU - Bai67 和 VNU - 18 对 C₂ 烃类的选择性分离性能。与许多报道的用于从 CH₄ 中分离 C₂ 烃类的金属有机框架相比，由于由间苯二甲酸类似物和 Cu - 桨轮单元构建的部分玉米 sql 层具有合适的孔径，它们对 C₂ 烃类表现出对 CH₄ 的高选择性吸附。有趣的是，随着 SNNU - Bai67 中 Cl 对 VNU - 18 中 OH 抗衡离子的调节，C₂ 烃类的吸附量值分别对 C₂H₂ 明显提高了 15.0%、对 C₂H₄ 提高了 20.4%、对 C₂H₆ 提高了 25.3%，而 C₂ 烃类/CH₄ 的 IAST 选择性仍然几乎相同，这可能是因为装饰框架的 Cl 的较弱极性增强了气体分子与框架之间 HO、HN/C、HC、π - π 或 HC 相互作用的协同效应。
