Distortable functionalized ligand implantation in ultra-microporous MOFs for efficient C2H2 purification

Abstract

Adsorption-based separation techniques are pivotal in the purification of C2H2, leveraging their eco-friendly and energy-efficient attributes. However, the reusability of adsorbents is highly restricted by the trade-off between adsorption capacity and adsorption enthalpy, which is required to be urgently addressed. Herein, we demonstrated that implantation of distortable ligands with functional groups is efficient to solve the above issue. The functional groups provided binding sites for C2H2 adsorption, while the distortable ligands optimized the pore structures to reduce adsorption enthalpy, thus balancing the trade-off between adsorption capacity and enthalpy. A series of ultra-microporous MOFs was successfully constructed via employing different pyridine ligands. The adsorption capacity was effectively enhanced, while the adsorption enthalpy nearly have not been increased due to the adjustable ligand torsion angle. Breakthrough experiments and GCMC simulations further verified the potential C2H2/CO2 separation applications.