Yi Mao, Wang Shan, Li Shenfang, Zhang Shuo, Liu Yilian, Zhang Laiyu, You Zifeng, Liu Xiongli, Li Lin, Wang Junhua, Wang Hao, Zhao Qiao, Li Baiyan, Bu Xian-He
School of Materials Science and Engineering, National Institute for Advanced Materials, TKL of Metal and Molecule-Based Material Chemistry, Nankai University, Tianjin 300350, P. R. China.
Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic University, Shenzhen, Guangdong 518055, P. R. China.
J Am Chem Soc. 2025 Apr 23;147(16):13592-13600. doi: 10.1021/jacs.5c00658. Epub 2025 Apr 8.
Exploring humidity-resistant, ethane-selective adsorbents for the one-step purification of polymer-grade (>99.95%) ethylene from ethane-ethylene mixtures is of great importance, yet remains a significant challenge. To address this challenge, we present a novel strategy for constructing a "superhydrophobic molecular selector" (SMS) based on a porous organic cage (POC), which features a superhydrophobic outer surface and an inner cavity with multiple ethane-selective functional sites. The resulting SMS-POC-1 demonstrates excellent CH adsorption capacity (97 cm g at 298 K) and CH/CH selectivity ( = 2.40 at 298 K), offering a superior trade-off between ethane adsorption capacity and CH/CH adsorption selectivity among all CH-selective adsorbents. Especially, breakthrough experiments demonstrate that SMS-POC-1 efficiently produces polymer-grade CH from CH/CH mixtures at 60% relative humidity (RH), making it the highest-selectivity adsorbent reported to date that can stably operate in a humid environment. The combination of experimental results and theoretical calculations reveals that the coexistence of a superhydrophobic outer surface and synergistic C-H···π interactions and hydrogen-bonding sites accounts for the high CH/CH separation performance under humid conditions for SMS-POC-1. Our work thus not only demonstrates a general strategy for guiding the design of humidity-resistant adsorption-separation materials but also presents a promising candidate for potential applications in hydrocarbon separation.
探索用于从乙烷 - 乙烯混合物中一步纯化聚合物级（>99.95%）乙烯的耐湿、乙烷选择性吸附剂具有重要意义，但仍然是一项重大挑战。为应对这一挑战，我们提出了一种基于多孔有机笼（POC）构建“超疏水分子选择器”（SMS）的新策略，该分子选择器具有超疏水外表面和带有多个乙烷选择性功能位点的内腔。所得的SMS-POC-1表现出出色的C₂H₆吸附容量（298 K时为97 cm³ g⁻¹）和C₂H₆/C₂H₄选择性（298 K时α = 2.40），在所有C₂H₄选择性吸附剂中，乙烷吸附容量和C₂H₆/C₂H₄吸附选择性之间实现了优异的平衡。特别是，突破实验表明，SMS-POC-1在60%相对湿度（RH）下能从C₂H₆/C₂H₄混合物中高效生产聚合物级C₂H₄，使其成为迄今为止报道的在潮湿环境中能稳定运行的最高选择性吸附剂。实验结果与理论计算相结合表明，超疏水外表面与协同的C-H···π相互作用和氢键位点的共存是SMS-POC-1在潮湿条件下具有高C₂H₆/C₂H₄分离性能的原因。因此，我们的工作不仅展示了指导耐湿吸附分离材料设计的通用策略，还为烃类分离的潜在应用提供了一个有前景的候选材料。
