|
Abstract
|
In this study, the CO2 capture efficiency of metal–organic frameworks (MOFs) was enhanced through post-synthetic alkali ion exchange, focusing specifically on the modification of UTSA-16. To address the urgent demand for efficient CO2 capture solutions in the face of rising greenhouse gas emissions, this work introduces a simple yet effective strategy to overcome the limitations of existing capture methods, which are often hampered by high regeneration costs and environmental concerns. By systematically substituting the K+ ions of UTSA-16 with smaller alkali cations, the CO2 affinity and adsorption efficiency of the framework were significantly improved. Comprehensive structural characterization and adsorption studies confirmed the successful ion-exchange process and identified 20-3_NaU as a standout material, exhibiting exceptionally high CO2 uptake (5.06 mmol/g) and CO2/N2 selectivity (438), along with excellent breakthrough separation performance, outstanding cyclic stability, and facile regeneration at ambient temperature. Density functional theory calculations further elucidated the mechanism underlying the enhanced CO2 capture performance of 20-3_NaU. These findings underscore the potential of alkali ion-exchanged MOFs, particularly 20-3_NaU, as highly efficient, cost-effective, and sustainable CO2 adsorbents.
|