Single-Step Ethylene Purification and MTO Product Separation in a Nitrogen-Rich Microporous Metal–Organic Framework

The nitrogen-rich metal-organic framework (MOF) NTUniv-75, featuring a melamine (MA) functional group, enables efficient one-step C₂H₄ purification and methanol-to-olefins (MTO) product separation. At 298 K, its adsorption capacity follows the order C₂H₂ > C₃H₆ > C₂H₆ > C₂H₄. Breakthrough experiments showed that NTUniv-75 produced pure C₂H₄ from C₂ mixtures with a productivity of 22.5 mL g^-1. For MTO products, productivities reached 43.0 mL g^-1 (C₂H₄) and 61.9 mL g^-1 (C₃H₆). Notably, C₃H₆ addition nearly doubled the C₂H₄ yield. Modeling revealed that MA aids C₂H₂/C₂H₄ separation, while pocket-like apertures favor C₂H₆ adsorption. Additionally, C-H···π interactions between C₂H₆ and C₃H₆ enhance C₂H₄ yield.