One-Step Ethylene Purification by an Ethane-Screening Metal-Organic Framework.

Efficient purification of ethylene (C 2 H 4 ) from ethane (C 2 H 6 ) is a crucial but daunting task for the chemical industry given their similar physical natures and molecular dimensions. Reversed capture of C 2 H 6 from C 2 H 6 /C 2 H 4 dual-mixtures can be expected to directly yield high-purity C 2 H 4 through a one-step separation unit, but it remains a daunting challenge. Here, we skillfully target an unusual "electrostatic-driven linker microrotation" ( EDLM ) in a Zr-MOF through coupling dual-ligands having electron-withdrawing/donating groups (e.g., F and CH 3 motifs). EDLM triggered microrotation of linker geometry and screening sites not only enhanced structural rigidity and hydrophobic nature, etc., but also effectively purified C 2 H 4 through reversely trapping C 2 H 6 . Under ambient conditions, 1 kg of activated 2 adsorbents directly produces 7.2 L of C 2 H 4 with over 99.9%+ purity in a single breakthrough operation starting from the equimolar C 2 H 6 /C 2 H 4 cracked mixtures. Geometrical models and simulations have revealed that EDLM -derived H-bonding interaction and microrotation of linker geometry, synergistically customized C 2 H 6 -selective screening sites and pore inert for reversed C 2 H 6 capture and improved surface hydrophobicity. Adsorption isotherms, modeling simulations, and breakthrough tests based on pressure swing adsorption (PSA) conditions have jointly elucidated the underlying separation properties for C 2 H 4 purification. The enhanced hydrophobic nature, cycling durability, and separation property awarded 2 a new benchmark adsorbent to purify the olefin/paraffin mixtures.