Robust Anion-Pillared Ultramicroporous Material for C₂H₂/C₂H₄ Separation with High C₂H₂ Uptake and Selectivity

Removing trace amounts of C₂H₂ from C₂H₂/C₂H₄ mixtures for C₂H₄ purification is crucial but extremely challenging. In this work, by introducing SiF₆^2- with specific recognition for C₂H₂, we constructed a robust adsorbent, FJI-W88, with a high C₂H₂ adsorption capacity and excellent C₂H₂/C₂H₄ separation selectivity. FJI-W88 not only exhibits ultrahigh C₂H₂ uptake at 0.01 bar (2.80 mmol g^-1) but also shows exceptional C₂H₂/C₂H₄ (1/99) IAST selectivity of 698. Column breakthrough experiments further demonstrate that FJI-W88 can obtain C₂H₄ of high purity (≥99.95%) and high yield (230.0 mol kg^-1) from C₂H₂/C₂H₄ (1/99) mixtures. Additionally, the C₂H₂/C₂H₄ (1/99) separation performance of FJI-W88 is basically unaffected under harsh conditions, such as high temperature and humidity.