College of Physical Science and Technology, Yangzhou University, Yangzhou, Jiangsu 225009, China.
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China.
Langmuir. 2023 Jun 27;39(25):8638-8645. doi: 10.1021/acs.langmuir.3c00474. Epub 2023 Jun 15.
Acetylene (CH) is an important and widely used raw material in various industries (such as petrochemical). Generally, a product yield is proportional to the purity of CH; however, CH from a typical industrial gas-production process is commonly contaminated by CO. So far, the achievement of high-purity CH separated from a CO/CH mixture is still challenging due to their very close molecular dimensions and boiling temperatures. Taking advantage of their quadrupoles with opposite signs, here, we show that the graphene membrane embedded with crown ether nanopores can achieve an unprecedented separation efficiency of CO/CH. Combining the molecular dynamics simulation and the density functional theory (DFT) approaches, we discovered that the electrostatic gas-pore interaction favorably allows the fast transport of CO through crown ether nanopores while completely prohibiting CH transport, which yields a remarkable permeation selectivity. In particular, the utilized crown ether pore is capable of allowing the individual transport of CO while completely rejecting the passage of CH, independent of the applied pressures, fed gases ratios, and exerted temperatures, featuring the superiority and robustness of the crown pore in CO/CH separation. Further, DFT and PMF calculations demonstrate that the transport of CO through the crown pore is energetically more favorable than the transport of CH. Our findings reveal the potential application of graphene crown pore for CO separation with outstanding performance.
乙炔（CH）是石化等各行业广泛应用的重要原料。一般来说，产物收率与 CH 的纯度成正比；然而，典型工业制气过程中的 CH 通常会被 CO 污染。迄今为止，由于 CO 和 CH 分子尺寸和沸点非常接近，从 CO/CH 混合物中分离出高纯度 CH 仍然具有挑战性。利用其具有相反符号的四极矩，我们在此展示，嵌入冠醚纳米孔的石墨烯膜可以实现前所未有的 CO/CH 分离效率。通过分子动力学模拟和密度泛函理论（DFT）方法，我们发现静电气体-孔相互作用有利于 CO 通过冠醚纳米孔快速传输，而完全阻止 CH 传输，从而产生显著的渗透选择性。特别地，所使用的冠醚孔能够允许 CO 单独传输，而完全阻止 CH 的通过，与施加的压力、进料气体比和施加的温度无关，这体现了冠孔在 CO/CH 分离中的优越性和稳健性。此外，DFT 和 PMF 计算表明，CO 通过冠醚孔的传输在能量上比 CH 的传输更有利。我们的研究结果表明，石墨烯冠醚孔在 CO 分离方面具有出色的性能，具有潜在的应用前景。
