Efficient separation of methanol-to-olefins products using a metal-organic framework with supramolecular binding sites

With the development of the methanol-to-olefins (MTO) process, research focus on the C₃H₆/C₂H₄ separation has become more urgent. The separation process based on physical adsorption has been widely studied due to its environmentally friendly and energy-efficient advantage. Herein, we reported a cage-like metal–organic framework which exhibits both high C₃H₆ adsorption capacity and excellent C₃H₆/C₂H₄ selectivity even at high temperatures. Dynamic breakthrough experiment shows it can realize the one-step acquisition of polymer-grade C₂H₄ (99.95 %) with an ultra-high productivity of 85.8 L∙kg⁻¹ at 298 K. Meanwhile, high purity C₃H₆ (99.5 %) can also be obtained in the desorption step, with a high productivity of 75.5 L∙Kg⁻¹. More importantly, both C₂H₄ and C₃H₆ yields can still be maintained even at high temperatures or with high gas flow rates, which is rarely reported and of great value for practical applications. Furthermore, density functional theory (DFT) simulation reveals that supramolecular binding sites play the key role in the remarkable C₃H₆/C₂H₄ separation performance.