A MOF-based Ultra-Strong Acetylene Nano-trap for Highly Efficient C₂ H₂ /CO₂ Separation

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 C₂ H₂ /CO₂ . Herein, we propose a new type of ultra-strong C₂ H₂ nano-trap based on multiple binding interactions to efficiently capture C₂ H₂ molecules and separate C₂ H₂ /CO₂ mixture. The ultra-strong acetylene nano-trap shows a benchmark Q_st of 79.1 kJ mol^-1 for C₂ H₂ , a record high pure C₂ H₂ uptake of 2.54 mmol g^-1 at 1×10^-2  bar, and the highest C₂ H₂ /CO₂ selectivity (53.6), making it as a new benchmark material for the capture of C₂ H₂ and the separation of C₂ H₂ /CO₂ . The locations of C₂ H₂ 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 C₂ H₂ .