Water-Resistant, Scalable, and Inexpensive Chiral Metal–Organic Framework Featuring Global Negative Electrostatic Potentials for Efficient Acetylene Separation

Abstract

Physical separation of acetylene (C 2 H 2 ) from carbon dioxide (CO 2 ) or ethylene (C 2 H 4 ) on metal−organic frameworks (MOFs) is crucial for achieving high-purity feed gases with minimal energy penalty. However, such processes are exceptionally challenging due to their close physical properties and are also critically restricted by the high cost of large-scale MOF synthesis. Here, we demonstrate the readily scalable synthesis of a highly water-resistant chiral Cu-MOF (TAMOF-1) based on an inexpensive proteogenic amino acid derivative bearing rich N/O sites. Notably, the unique coordination in this ultramicroporous MOF has resulted in the generation of rare global negative electrostatic potentials, which greatly facilitate the electrostatic interactions with C 2 H 2 molecules, thus leading to their efficient separation from C 2 H 2 /CO 2 and C 2 H 2 /C 2 H 4 mixtures under ambient conditions. The separation efficiency and mechanism are unequivocally validated by breakthrough experiments and computational simulations. This work not only highlights the pivotal role of creating a negative electro-environment in confined spaces for boosting C 2 H 2 capture and separation but also opens up new ways of employing cheap amino acid derivatives bearing rich electro-negative N and O sites as organic linkers to constructing highperforming MOF materials for gas separation purposes.