The efficient separation of acetylene (C₂H₂) from carbon dioxide (CO₂) and C_nH₄ (n = 1 and 2) to manufacture high purity C₂H₂ and recover other light hydrocarbons is technologically important, while posing significant challenges. Herein, we reported a new TiF₆²₋ anion (TIFSIX) pillared metal-organic framework (MOF) ZNU-5 (ZNU = Zhejiang Normal University) with ultramicropores for highly selective C₂H₂ capture with low adsorption heat through gate opening based molecular sieving effect. ZNU-5 takes up a large amount of C₂H₂ (128.6 cm³/g) at 1.0 bar and 298 K but excludes CO₂, CH₄, and C₂H₄. Such high capacity has never been realized in MOFs with molecular sieving. The breakthrough experiments further confirmed the highly selective C2H2 separation performance from multi-component gas mixtures. 3.3, 2.8, and 2.2 mmol/g of C₂H₂ is captured at ZNU-5 from equimolar C₂H₂/CO₂, C₂H₂/CO₂/CH₄, and C₂H₂/CO₂/CH₄/C₂H₄ mixtures, respectively. Furthermore, 2.6, 2.0, and 1.5 mmol/g of > 98% purity C₂H₂ can be recycled from the desorption process. Combining high working capacity, low adsorption heat, as well as good recyclability, ZNU-5 is promising for C₂H₂ purification.

将乙炔 (C ₂ H ₂ ) 从二氧化碳 (CO ₂ ) 和 C _n H ₄ ( n = 1 和 2) 中高效分离以制造高纯度 C ₂ H ₂并回收其他轻烃在技术上很重要，同时对挑战。在此，我们报道了一种新型 TiF ₆ ² _-阴离子 (TIFSIX) 柱状金属有机骨架 (MOF) ZNU-5 (ZNU = 浙江师范大学)，具有超微孔，可通过基于栅极开口的低吸附热高选择性捕获C ₂ H ₂分子筛效应。ZNU-5占用大量C₂ H ₂ (128.6 cm ³ /g) 在 1.0 bar 和 298 K 但不包括 CO ₂、CH ₄和 C ₂ H ₄。如此高的容量在具有分子筛分的 MOF 中从未实现过。突破性实验进一步证实了从多组分气体混合物中分离 C2H2 的高选择性性能。在 ZNU-5 从等摩尔 C ₂ H ₂ /CO ₂、C ₂ H ₂ /CO ₂ /CH ₄和 C ₂ H ₂ /CO中捕获 3.3、2.8和 2.2 mmol/g 的 C ₂ H ₂₂ /CH ₄ /C ₂ H ₄混合物。此外，2.6、2.0 和 1.5 mmol/g 的纯度 > 98% 的 C ₂ H ₂可以从解吸过程中回收。ZNU-5结合了高工作容量、低吸附热以及良好的可回收性，有望用于C ₂ H ₂净化。