A scalable zinc-based coordination network for energy-efficient NF/CF separation with unprecedented selectivity.

Nitrogen trifluoride (NF) and carbon tetrafluoride (CF) are critical gases in the semiconductor industry. However, their current lack of effective recycling and separation results in significant waste emissions, which are not only costly but also pose significant environmental challenges. Their separation remains a critical challenge due to their nearly identical physicochemical properties (Δbp <1 °C, similar polarizability). Here, we demonstrate that a zinc-based metal-organic framework (CALF-20) with precisely tuned 4.8 Å pores achieves exceptional NF/CF separation through molecular sieving. At 298 K, this material exhibits a record-high NF/CF adsorption ratio of 41.1, and a CF purity of 99.5% can be achieved through breakthrough experiments. Structural characterization and computational studies reveal that the unique pore channel properties preferentially adsorb NF (kinetic diameter: 4.5 Å) while effectively excluding CF (4.8 Å). This advance enables cost-effective gas purification at $12.3 per kilogram, providing a practical solution for sustainable semiconductor manufacturing.