Trace Capture Hexafluoropropylene From Octafluoropropane via Complete Molecular Sieving Mechanism in a Highly Robust Metal−Organic Framework

Deep removal of trace hexafluoropropylene (C₃F₆) impurity from octafluoropropane (C₃F₈) using porous adsorbents is highly promising, but the field still suffers from the lack of benchmark adsorbents capable of overcoming the inherent trade-off between adsorption capacity and uptake ratio. Herein, we report a highly robust metal-organic framework, Ni-pca-pyz, which features an electrostatic-potential complementary surface and molecular-sieving channel tailored for C₃F₆, realizes the optimal accommodation of C₃F₆ and complete exclusion of C₃F₈. Ni-pca-pyz exhibits a record-high C₃F₆/C₃F₈ uptake ratio (137.6), coupled with exceptional C₃F₆ adsorption capacity (55.02 cm³ g^-1) at 298 K and 1.0 bar. Kinetic analysis further confirms negligible adsorption of C₃F₈ (0.36 cm³ g^-1) in Ni-pca-pyz, and effective diffusion coefficient for C₃F₆ is 9.29 × 10^-5 s^-1 at 298 K. Molecular simulations and in situ Fourier transform infrared spectroscopy (FTIR) elucidate the synergetic effect of pore confinement, and surface electrostatic complementarity confers high recognition of C₃F₆ through multiple hydrogen bonding interactions. The column breakthrough experiments validate the efficient removal of trace C₃F₆ from C₃F₈, affording an excellent C₃F₈ productivity of 2.06 × 10³ L kg^-1 (purity exceeding 99.999%). With its outstanding stability, recyclability, and low-cost precursors, Ni-pca-pyz provides an ideal platform for industrial perfluorinated electronic specialty gases (ESGs) purification.