Control of zeolite local microenvironment by organofluorination engineering toward efficient c-C4F8/C3F8 separation

Ultrahigh-purity octafluoropropane (C ₃ F ₈ ) electronic specialty gas is of critical importance for advanced semiconductor and integrated circuit manufacturing. The removal of trace amounts of octafluorocyclobutane ( c -C ₄ F ₈ ) impurities from C ₃ F ₈ products remains a challenging endeavor due to their similar physiochemical properties. Herein, an organofluorination engineering strategy is reported to regulate the local microenvironment of zeolite Y for efficient c -C ₄ F ₈ /C ₃ F ₈ adsorptive separation. The organofluorinated zeolite Y adsorbents exhibit enhanced c -C ₄ F ₈ /C ₃ F ₈ separation efficiency compared to pristine zeolite, with remarkably greater uptakes of c -C ₄ F ₈ and lower uptakes of C ₃ F ₈ . Notably, sample ZnY-FU achieves an ultrahigh c -C ₄ F ₈ /C ₃ F ₈ selectivity of 1.7´10 ¹⁰ at 1 bar and 25 °C. Multiple characterizations and theoretical calculations reveal that the local microenvironment of zeolite Y can be regulated with the fluorinated ligands located at FAU supercages close to the pore entrance. The introduction of fluorinated ligands mainly affects the thermodynamic adsorption behaviors of c -C ₄ F ₈ and C ₃ F ₈ on the adsorbents, resulting in highly efficient c -C ₄ F ₈ /C ₃ F ₈ separation. Dynamic breakthrough experiments further verify the c -C ₄ F ₈ /C ₃ F ₈ separation potentials with ultrahigh-purity C ₃ F ₈ (99.999%) obtained from c -C ₄ F ₈ /C ₃ F ₈ (5: 95, v/v) mixtures.