Pore Modulation by CF3-Decorated Pyridine Rings Enables Direct Ethylene Purification from C2 Hydrocarbons

Abstract Direct purification of ethylene from C2 hydrocarbon mixtures remains challenging due to their similar physicochemical properties. Herein, we report NTUniv-65, a Cu2 paddlewheel-based metal–organic framework constructed from CF3-functionalized pyridine dicarboxylate ligands. The inward-oriented CF3-decorated pyridine rings regulate the pore aperture and local adsorption environment, inducing an unusual adsorption sequence of C2H2 > C2H6 > C2H4 through enhanced confinement and host–guest interactions. Experimental measurements and molecular simulations provide molecular-level insight into this selective adsorption behavior. NTUniv-65 exhibits separation of C2H2 and C2H6 from C2H4, enabling one-step purification of ethylene from a realistic C2H2/C2H6/C2H4 (1/9/90) mixture with an ethylene yield of 22.1 cm3 g–1. This work highlights pore modulation by functionalized ligands as an effective strategy for challenging hydrocarbon separations.