A scalable stable porous coordination polymer synthesized from low-cost precursors for efficient C2H2/C2H4 separation

Abstract

The separation of C₂H₂/C₂H₄ is a challenging task, and adsorptive separation based on porous materials offers a promising energy-efficient alternative. Porous coordination polymers (PCPs) have been advocated as potential adsorbents with high separation performance (adsorption capacity and selectivity) by precisely tuning their pore size and chemistry. However, to achieve the goal of green chemistry and pioneer PCPs for practical applications, not only the separation performance but also low regeneration energy and synthetic cost are crucial factors. We herein prepared a novel PCP TJE-1 with rational distribution of cooperative supramolecular interaction sites, exhibiting a very high C₂H₂ uptake of 5.27 mmol g⁻¹, and a C₂H₂ selective adsorption over C₂H₄ under 1 bar, at 298 K. Theoretical calculations indicate that the selectivity originates from the difference in hydrogen bonding and π interactions, resulting in a low isosteric heat of adsorption for C₂H₂ (35.5 kJ mol⁻¹). Moreover, TJE-1 also remains stable in aqueous acid/base solutions and can be synthesized with scaling up using economical precursors (about $1.45 per g and $0.13 per g for two ligands). This strategy offers guidance on the development of next-generation PCPs with integrated performance that is highly beneficial for industrial gas separations.