Du Guo-Tong, Wang Yi, Liu Teng-Long, Yue Zheng-Qi, Ma Ya-Nan, Xue Dong-Xu
Institute of New Concept Sensors and Molecular Materials, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P. R. China.
Chemistry. 2025 Jan 17;31(4):e202403478. doi: 10.1002/chem.202403478. Epub 2024 Nov 22.
Achieving a balance between high selectivity and uptake is a formidable challenge for the purification of acetylene from mixtures with carbon dioxide, particularly when seeking to maximize both CH adsorption capacity and CH/CO separation selectivity in crystalline porous materials. In this study, leveraging the principles of reticular chemistry, we selected two tetracarboxylate-based linkers and combined them with Cu ions to synthesize two isoreticular dicopper paddle-wheel-based metal-organic frameworks (MOFs): Cu-TPTC (terphenyl-3,3',5,5'-tetracarboxylic acid, HTPTC) and Cu-ABTC (3,3,5,5-azobenzenetetracarboxylic acid, HABTC). The structural and sorption analyses revealed that Cu-ABTC, despite having slightly smaller pores due to the strategic replacement of a phenyl ring with an azo group between two tetratopic ligands, maintains high porosity compared to Cu-TPTC. Furthermore, Cu-ABTC outperforms Cu-TPTC in terms of CH adsorption capacity (196 cm g at 298 K and 1 bar) and CH/CO separation selectivity (16.5~5.6). These findings were corroborated by dynamic breakthrough experiments and computational modeling. This research highlights the potential of the isoreticular contraction strategy in enhancing MOFs for sophisticated gas adsorption and separation processes.
对于从二氧化碳混合物中纯化乙炔而言，要在高选择性和高吸附量之间取得平衡是一项艰巨的挑战，特别是在寻求使结晶多孔材料中的CH吸附容量和CH/CO分离选择性均达到最大化时。在本研究中，我们利用网状化学原理，选择了两种基于四羧酸的连接体，并将它们与铜离子结合，合成了两种同构的基于双铜桨轮的金属有机框架（MOF）：Cu-TPTC（三联苯-3,3',5,5'-四羧酸，HTPTC）和Cu-ABTC（3,3,5,5-偶氮苯四羧酸，HABTC）。结构和吸附分析表明，尽管由于在两个四齿配体之间用偶氮基团策略性地取代了一个苯环，Cu-ABTC的孔径略小，但与Cu-TPTC相比，它仍保持着高孔隙率。此外，在CH吸附容量（298 K和1 bar下为196 cm³ g⁻¹）和CH/CO分离选择性（16.5~5.6）方面，Cu-ABTC优于Cu-TPTC。动态突破实验和计算模拟证实了这些发现。这项研究突出了同构收缩策略在增强MOF用于复杂气体吸附和分离过程方面的潜力。
