Construction of Negative Electrostatic Pore Environments in a Scalable, Stable and Low-Cost Metal-organic Framework...

One-step separation of C₂ H₄ from ternary C₂ mixtures by physisorbents remains a challenge to combine excellent separation performance with high stability, low cost, and easy scalability for industrial applications. Herein, we report a strategy of constructing negative electrostatic pore environments in a stable, low-cost, and easily scaled-up aluminum MOF (MOF-303) for efficient one-step C₂ H₂ /C₂ H₆ /C₂ H₄ separation. This material exhibits not only record high C₂ H₂ and C₂ H₆ uptakes, but also top-tier C₂ H₂ /C₂ H₄ and C₂ H₆ /C₂ H₄ selectivities at ambient conditions. Theoretical calculations combined with in situ infrared spectroscopy indicate that multiple N/O sites on pore channels can build a negative electro-environment to provide stronger interactions with C₂ H₂ and C₂ H₆ over C₂ H₄ . Breakthrough experiments confirm its exceptional separation performance for ternary mixtures, affording one of the highest C₂ H₄ productivity of 1.35 mmol g^-1 . This material is highly stable and can be easily synthesized at kilogram-scale from cheap raw materials using a water-based green synthesis. The benchmark combination of excellent separation properties with high stability and low cost in scalable MOF-303 has unlocked its great potential in this challenging industrial separation.