Abstract
Simultaneously removing ethane (C(2)H(6)) and acetylene (C(2)H(2)) from ethylene (C(2)H(4)) streams is advantageous for industrial production yet remains challenging for physisorbents. Herein, we report a microporous metal-organic framework (MOF), NKM-47, that achieves one-step C(2)H(4) purification. NKM-47 was designed via a supramolecular linker-directed assembly approach and features a 'trap-and-diffusion' porous architecture composed of orthogonally arranged molecular pockets and 1D channels. The N/O-rich molecular pockets selectively capture the smallest and largest C(2) species (C(2)H(2) and C(2)H(6)) while the channels permit preferential diffusion of medium-sized C(2)H(4). NKM-47 enables one-step production of polymer-grade C(2)H(4) (99.99% purity) from both binary and ternary C(2) gas mixtures under ambient conditions. This study presents the first example of a trap-and-diffusion mechanism for C(2) hydrocarbon separation in MOFs, enabling the single-step purification of C(2)H(4) through the selective diffusion of a species with intermediate physicochemical properties.