Adsorptive separation of acetylene (C₂H₂) from a C₂H₂/CO₂ mixture has emerged as an alternative to replace cryogenic distillation to obtain high purity C₂H₂ in a safer manner. Al-based metal–organic frameworks, such as MIL-160 and CAU-10–NH₂, have been reported as good acetylene adsorbents with high selectivity and high acetylene packing density. According to this, incorporation of hetero atoms in the MOF pore wall clearly has a positive impact on enhancing C₂H₂ capture performance. Nonetheless, a systematic evaluation of the role played by functional groups within the same MOF structure in their C₂H₂ sorption performance is still required. In this study, CAU-10 samples were prepared according to the functional group using Al metal ions and various functionalized organic linkers, including pristine terephthalate (–H) and its modified forms (–OH, –F, –NO₂, –NH₂, and –CH₃) to investigate their C₂H₂ and CO₂ adsorption properties. The C₂H₂/CO₂ separation performance of the adsorbents was investigated using single gas adsorption isotherms and by application of the ideal adsorbed solution theory as well as dynamic breakthrough experiments for the gas mixture under dry and humid conditions. Interestingly, CAU-10–CH₃ was demonstrated to exhibit a record high packing density of 543 g L⁻¹ at 25 °C for acetylene, 2.8 times higher than the CO₂ uptake at 1 bar. A breakthrough mixture experiment using CAU-10–CH₃, and CAU-10–NH₂ as comparative samples confirmed CAU-10–CH₃ as a prominent candidate for acetylene selective adsorption under both dry and humid conditions. The microscopic origin of these attractive adsorption/separation performances was understood from density functional theory calculations and single component/binary mixture grand canonical Monte Carlo simulations.

中文翻译：

---

CAU-10(Al) 的官能团调整可实现高效 C2H2 存储和 C2H2/CO2 分离


从C ₂ H ₂ /CO ₂混合物中吸附分离乙炔(C ₂ H ₂ )已成为替代低温蒸馏的替代方案，从而以更安全的方式获得高纯度C ₂ H ₂ 。铝基金属有机骨架，如MIL-160和CAU-10-NH ₂ ，已被报道为良好的乙炔吸附剂，具有高选择性和高乙炔填充密度。据此，MOF孔壁中杂原子的掺入显然对增强C ₂ H ₂捕获性能具有积极影响。尽管如此，仍然需要对同一MOF结构内的官能团在其C ₂ H ₂吸附性能中所起的作用进行系统评估。在本研究中，CAU-10样品根据官能团使用Al金属离子和各种官能化有机连接体制备，包括原始对苯二甲酸酯（–H）及其改性形式（–OH、–F、–NO ₂ 、–NH ₂ ，和-CH ₃ ）来研究它们的C ₂ H ₂和CO ₂吸附性能。 利用单一气体吸附等温线，应用理想吸附溶液理论以及干湿条件下气体混合物的动态突破实验，研究了吸附剂的C ₂ H ₂ /CO ₂分离性能。有趣的是，CAU-10–CH ₃被证明在 25 °C 下乙炔表现出创纪录的 543 g L ^-1堆积密度，比 1 bar 下的 CO ₂吸收高 2.8 倍。使用 CAU-10–CH ₃和 CAU-10–NH ₂作为比较样品进行的突破性混合物实验证实，CAU-10–CH ₃是干燥和潮湿条件下乙炔选择性吸附的重要候选者。这些有吸引力的吸附/分离性能的微观起源可以通过密度泛函理论计算和单组分/二元混合物大正则蒙特卡罗模拟来理解。