Li Yi-Tao, Li Weilin, Zhang Li-Ping, Geng Na, Xu Li, Wang Shao-Min, Zhu Tingyu, Guan Qingqing, Guo Yangyang, Li Xingxing, Yang Qing-Yuan
State Key Laboratory of Fluorine & Nitrogen Chemicals, National Innovation Platform (Center) for Industry-Education Integration of Energy Storage Technology, School of Chemical Engineering and Technology, Xi'an Jiaotong University Xi'an 710049 China
Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China Anhui 230026 China
Chem Sci. 2025 Aug 6. doi: 10.1039/d5sc04966k.
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.
三氟化氮（NF）和四氟化碳（CF）是半导体行业中的关键气体。然而，它们目前缺乏有效的回收和分离，导致大量废气排放，这不仅成本高昂，还带来了重大的环境挑战。由于它们的物理化学性质几乎相同（沸点差<1°C，极化率相似），它们的分离仍然是一个关键挑战。在这里，我们证明了一种具有精确调谐的4.8 Å孔径的锌基金属有机框架（CALF-20）通过分子筛实现了卓越的NF/CF分离。在298 K时，这种材料表现出创纪录的41.1的NF/CF吸附比，通过突破实验可以实现99.5%的CF纯度。结构表征和计算研究表明，独特的孔道性质优先吸附NF（动力学直径：4.5 Å），同时有效排除CF（4.8 Å）。这一进展使得每千克成本为12.3美元的经济高效气体净化成为可能，为可持续半导体制造提供了切实可行的解决方案。
