Adsorptive recovery of <scp> NF ₃ </scp> and <scp> CF ₄ </scp> using a

Abstract

Recovering nitrogen trifluoride (NF 3 ) and carbon tetrafluoride (CF 4 ) from semiconductor‐related streams is a process challenge for electronic‐gas reuse and greenhouse‐gas mitigation. Here, we report the efficient NF 3 /CF 4 sieving separation through a flexible one‐dimensional MOF, Mn‐dhbq, that exhibits a temperature‐responsive “gate‐opening” effect. At 298 K and 1 bar, Mn‐dhbq adsorbs 1.24 mmol·g −1 of NF 3 while showing negligible uptake of CF 4 (0.14 mmol·g −1 ), leading to an ideal adsorbed solution theory (IAST) selectivity of 10.6 for an equimolar mixture. Dynamic breakthrough experiments confirm that high‐purity CF 4 (≥ 99.5%) and NF 3 (≥ 99.5%) can be recovered during the adsorption and desorption process, respectively. And the separation performance could maintain for at least 5 cycles without degradation. Moreover, Mn‐dhbq can be synthesized on a hundred‐gram scale in water at room temperature and shaped into pellets with a hydroxyethyl cellulose binder. These combined properties make Mn‐dhbq a promising adsorbent for practical NF 3 /CF 4 separation.