A Rigid, Stable, and Scalable Aliphatic MOF Adsorbent for Efficient C<sub>2</sub>H<sub>2</sub>/CO<sub>2</sub> Separation with Record Acetylene Packing Density
Shuangqing Shang, Zhenwei Zhou, Hao Wang, Yanan Wang, Xing Liu, Zhenglong Zhu, Yong Zeng, Cheng Liu, Hanting Xiong, Hao Liu, Fangxin Zhao, Jingwen Chen, Shixia Chen, Zhenyu Zhou, Jun Wang
Abstract
Abstract Integrating separation parameters such as high adsorption capacity and selectivity, moderate adsorption enthalpy ( Q st ), along with industrial factors including cyclic stability, cost‐effectiveness, and scalability into a single adsorbent remains highly challenging due to inherent trade‐offs among these properties. Herein, we strategically leverage the coordination modes of aliphatic ligands to significantly enhance C 2 H 2 /CO 2 separation performance. The structure flexibility and pore metrics are finely modulated by hydroxylated aliphatic acid (DLmal). As a result, the rigid Zn‐bpy‐DLmal exhibits an exceptional C 2 H 2 adsorption capacity of 1.4 mmol g −1 at 0.01 bar, high C 2 H 2 /CO 2 selectivity (49), and moderate C 2 H 2 Q st value (38.4 kJ mol −1 ). Notably, it achieves record‐high C 2 H 2 packing densities of 347 g L −1 at 0.01 bar and 747 g L −1 at 0.5 bar. Furthermore, the scale‐up production of Zn‐bpy‐DLmal to kilogram quantities has been successfully achieved at an estimated cost of $74 per kilogram. Dynamic breakthrough experiments confirm its practical C 2 H 2 /CO 2 separation performance with excellent cyclability under high flow rates and both dry and humid conditions. Moreover, two‐bed pressure swing adsorption simulations demonstrate a high‐purity C 2 H 2 (>99%) yield of 14.64 mol with a recovery of 88.2% per cycle.