Yao Jiang, Shungang Yang, Mingming Xu, Cheng-Xu Rong, Kang Wang, Qi Wang, Peng Cui, Lin‐Bing Sun
The development of efficient adsorbents for the selective separation of C 2 H 2 from gas mixtures containing impurities of C 2 H 4 and CO 2 during C 2 H 2 production is critically important and challenging. In this study, two adenine-based MOFs, Zn-AD-BDC and Cu-AD-BDC, were fabricated as adsorbents. The obtained materials feature rich Lewis basic sites (LBS) within their pore environments, which serve as the primary adsorption sites for C 2 H 2 binding. Notably, Cu-AD-BDC, with abundant micropores and a higher density of LBS within the pore channels compared to Zn-AD-BDC, demonstrated superior C 2 H 2 separation performance. Adsorption isotherms and breakthrough curve experiments revealed that Cu-AD-BDC demonstrated remarkably higher C 2 H 2 adsorption capacity and greater adsorption selectivity for C 2 H 2 over C 2 H 4 and CO 2 than Zn-AD-BDC. Computational simulations further elucidated that the enhanced C 2 H 2 separation of Cu-AD-BDC results from the synergy between its specific microporous structure and the interactions of LBS with gas molecules through the strong C–H···N/O hydrogen bonds and C–H···π interactions, which facilitate the selective adsorption of C 2 H 2 from the gas mixtures.