High-capacity dynamic exclusion for highly efficient dilute C2H2 separation from CO2 and multicomponent mixture in robust ultramicroporous MOF by topology regulation

Abstract

Acquiring high C2H2 adsorption capacity and effectively separating it from the most difficult-to-separate byproduct CO2 in a dilute state are crucial for obtaining high productivity/purity monomer for polymers. Here, we address this challenge through topology regulation of fluorinated ultramicroporous metal–organic framework, producing a new hydrolytically stable adsorbent, ZUL-500. Uncovered by X-ray diffraction and modeling, a more favorable spatial distribution of GeF62- anions for C2H2 recognition is realized in sql topological ZUL-500 compare to ZU-32 with the same anion and metal node but pcu topology, offering remarkably increased C2H2 affinity and amplified C2H2/CO2 affinity difference that affords a dynamic exclusion of CO2 but excellent C2H2 adsorption in fixed-bed separation even for industrial-related mixtures (up to 8 components). Excellent values were simultaneously obtained for C2H2 uptake capacity, C2H2/CO2 separation factor and C2H2 productivity, coupled with good mass transfer and recyclability, providing exceptional productivity (2.92 ∼ 3.48 mmol g−1) of high purity (≥99.6%) C2H2 from mixtures.