Pore‐Surface Charge Engineered Anion‐Pillared MOFs With Tailored Electronegative Narrow Windows for Simultaneous Thermodynamic and Kinetic Separation of MTO Products

ABSTRACT The development of separable adsorbents for the efficient separation of ethylene (C 2 H 4 ) and propylene (C 3 H 6 ) from methanol‐to‐olefin (MTO) products is regarded as a sustainable approach to supply vital industrial feedstocks, thus holding critical significance. Herein, we synthesized a new material SIFSIX‐DPU‐Cu using 1,3‐di(pyridin‐4‐yl) urea (DPU) ligand for the separation of MTO products (C 3 H 6 /C 2 H 4 mixtures), and which features the scarcely explored characters concurrently integrating rich F‐containing [Cu 4 (μ 3 ‐F) 4 ] 2+ cation clusters and SiF 6 2− anion pillars. By constructing continuous electronegative pore surfaces with rich active sites and dumbbell‐shaped pores, the material can preferentially adsorb C 3 H 6 rather than C 2 H 4 and exhibit significantly high C 3 H 6 /C 2 H 4 adsorption selectivity. The dynamic breakthrough experiment on equimolar C 3 H 6 /C 2 H 4 mixtures shows that following one separation cycle at 298 K, SIFSIX‐DPU‐Cu enables to separate and produce 38.3 L kg −1 C 2 H 4 (purity ≥ 99.95%) and 46.2 L kg −1 C 3 H 6 (purity ≥ 99.5%) simultaneously. Experimental results based on single crystal analysis together with simulations reveal an uncommon simultaneous thermodynamic and kinetic separation mechanism in which the narrow pore window and enlarged F‐rich cavity synergistically generate restricted binding sites, leading to significant selectivity in the competitive adsorption of C 3 H 6 over C 2 H 4 .