An adenine-based metal-organic framework with tailored pore environment for adsorption separation of C2H2 from C2H4 and CO2

The separation of acetylene (C 2 H 2 ) from mixtures with ethylene (C 2 H 4 ) and carbon dioxide (CO 2 ) is crucial yet challenging in the chemical industry. Based on the adsorption separation technology, it is desirable to design and develop efficient adsorbents for C 2 H 2 separation. In this work, we present an adenine-based metal-organic framework (Cu-AD-HEA), which features tailored pore environment with Lewis basic sites within the specific intersecting channels for the separation of C 2 H 2 from mixtures with C 2 H 4 and CO 2 . The obtained Cu-AD-HEA exhibits exceptional adsorption capacity for C 2 H 2 and demonstrates competitive adsorption selectivity for C 2 H 2 /C 2 H 4 and C 2 H 2 /CO 2 . Furthermore, dynamic breakthrough results further illustrate the superior dynamic separation of C 2 H 2 over C 2 H 4 and CO 2 . Moreover, detailed molecular simulations and density functional theory (DFT) calculations elucidate that C 2 H 2 is preferentially captured in a tailored pore environment of Cu-AD-HEA with stronger binding affinity through C H⋯N/O hydrogen bonds and C–H⋯π or π⋯π interactions. This work offers an effective MOF-based adsorbent for the separation of C 2 H 2 from mixtures with C 2 H 4 and CO 2 .