Meng Sun, Hongyan Liu, Xiaokang Wang, Xinlei Yang, Fei Gao, Deyu Xie, Weidong Fan*, Yinfeng Han*, Ben Xu, Daofeng Sun

Cite this article: Chin. J. Struct. Chem., 2023, 42: 100146. DOI: 10.1016/j.cjsc.2023.100146

Publication date: September 15, 2023

Keywords: Metal-organic framework; Isoreticular chemistry; Metal ion regulation; C2H2/CO2 separation

ABSTRACT

Adsorptive separation of acetylene (C2H2) from carbon dioxide (CO2) by adsorption is a viable method for producing high-purity C2H2 required for industrial applications. However, separating C2H2 and CO2 is challenging due to their extremely similar molecular sizes and physical properties. Metal-Organic Frameworks (MOFs), as a novel porous material with high specific surface area and tunable pore size, have shown great potential in the separation and purification of light hydrocarbons. Herein, we synthesized three isoreticular Al-MOFs (Al-TCPP, Al-TCPP(Co), and Al-TCPP(Fe)) by modulating metal ions at the porphyrin center, all of which can effectively separate C2H2/CO2. The addition of metal ions can regulate and improve the separation selectivity of C2H2/CO2. Compared with the parent Al-TCPP, the IAST selectivities of Al-TCPP(Co) and Al-TCPP(Fe) for equimolar C2H2/CO2 increased from 1.73 to 3.66 and 4.43, respectively. Breakthrough experiments validate their efficient separation of C2H2/CO2. Furthermore, they all exhibit excellent hydrothermal stability, laying the foundation for practical applications.