A MOF‐based Ultra‐Strong Acetylene Nano‐trap for Highly Efficient C2H2/CO2 Separation

• Published in: Angewandte Chemie International Edition Vol. 60; no. 10; pp. 5283 - 5288
• Main Authors: Niu, Zheng, Cui, Xili, Pham, Tony, Verma, Gaurav, Lan, Pui Ching, Shan, Chuan, Xing, Huabin, Forrest, Katherine A., Suepaul, Shanelle, Space, Brian, Nafady, Ayman, Al‐Enizi, Abdullah M., Ma, Shengqian
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.03.2021
• Edition: International ed. in English
• Subjects: Acetylene; acetylene nano-trap; Benchmarks; Binding sites; C2H2/CO2 separation; Carbon dioxide; Gas mixtures; in situ single-crystal X-ray diffraction; Metal-organic frameworks; MOFs; Porous materials; Selectivity; Separation
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202016225

Porous materials with open metal sites have been investigated to separate various gas mixtures. However, open metal sites show the limitation in the separation of some challenging gas mixtures, such as C2H2/CO2. Herein, we propose a new type of ultra‐strong C2H2 nano‐trap based on multiple binding interactions to efficiently capture C2H2 molecules and separate C2H2/CO2 mixture. The ultra‐strong acetylene nano‐trap shows a benchmark Qst of 79.1 kJ mol−1 for C2H2, a record high pure C2H2 uptake of 2.54 mmol g−1 at 1×10−2 bar, and the highest C2H2/CO2 selectivity (53.6), making it as a new benchmark material for the capture of C2H2 and the separation of C2H2/CO2. The locations of C2H2 molecules within the MOF‐based nanotrap have been visualized by the in situ single‐crystal X‐ray diffraction studies, which also identify the multiple binding sites accountable for the strong interactions with C2H2. A new type of ultra‐strong C2H2 nano‐trap featuring the synergistic effect of multiple open metal sites has been proposed for separating C2H2/CO2 mixture gas. The unique C2H2 nano‐trap shows the strongest binding interaction with C2H2 and a benchmark for C2H2/CO2 separation. The binding mechanism for C2H2 was studied through single‐crystal X‐ray diffraction experiments and molecular simulation studies.