Synthesis and Modification of Formate Zr‐MOF (ZrFA) Toward Scalable and Cost‐Cutting Gas Separation

Abstract The mass production of metal‐organic frameworks (MOFs) with affordable cost is highly demanding yet limited for commercial applications, e.g., purification of polymer‐grade ethylene (C 2 H 4 ) via acetylene (C 2 H 2 ) and carbon dioxide (CO 2 ) removal faces the challenge of developing low‐cost and large‐scale physisorbents with efficiency and recyclability. Herein, we developed a viable synthetic protocol to scale‐up a series of ultramicroporous Zr‐MOFs (ZrFA/ZrFA‐D/ZrFA‐D‐Cu(I)) with the simplest monocarboxylate, formate (FA), through consecutive production by recycling solvent/modulator. Besides a size‐exclusion effect disfavoring C 2 H 4 adsorption, introduction of defective and Cu(I) sites was found to enhance gas affinity and uptake capacity. A comprehensive evaluation of C 2 H 4 separation and economic efficiency has been proposed, suggesting the improvement of C 2 H 2 uptake capacity is effective for the binary C 2 H 2 /C 2 H 4 separation, while the separation process of the ternary C 2 H 2 /CO 2 /C 2 H 4 mixtures depends on subtle tradeoff of complex factors and limited by challenging CO 2 /C 2 H 4 separating. Notably, the large‐scale separation has been testified to significantly improve separation efficiency, and the low‐cost preparation benefits high economic efficiency. The distinct C 2 H 2 /C 2 H 4 /CO 2 adsorption mechanism in ZrFA/ZrFA‐D/ZrFA‐D‐Cu(I) has been elucidated by the theoretical calculations. This work may shed a light on the future C 2 H 4 purification technology by pushing MOF‐syntheses toward low‐cost, scale‐up, and recyclable production.