A multi-dimensional analysis of microporous materials for advancing CO2 capture

The escalating atmospheric CO 2 concentration calls for advanced carbon capture solutions. However, developing a stable and efficient adsorbent with high selectivity for CO 2 capture remains a significant challenge. Microporous materials capture CO 2 primarily through physisorption based on pore structure and van der Waals forces. In this study, three silicon-aluminum zeolite molecular sieve materials were synthesized and hydrophilic modification of ZIF-8 was achieved through post-synthetic coordination with polyethylene glycol. A systematic comparison of the CO 2 adsorption performance of these materials under different conditions was then conducted. Zeolites exhibited exceptional thermal stability (< 5% mass loss from 25-800 °C under an air atmosphere) and cyclability (retaining > 95% of initial adsorption capacity throughout cycling), outperforming ZIF-8 analogues. 85-nm zeolite achieved the optimal CO 2 uptake (1.8 mmol g -1 ) at 25 °C and ZIF-8 showed the best humidity resistance (40% decrease at 80% RH). Additionally, ZSM-5 exhibited enhanced gas retention of 1498 s, indicating superior CO 2 adsorption affinity. These results demonstrate the excellent thermal stability and cycling stability of the zeolite materials. This study provides actionable insights for future material design: 1) prioritizing zeolite-based frameworks for scenarios requiring long-term cyclic stability and thermal robustness; 2) optimizing pore size and surface properties to balance adsorption capacity and selectivity; 3) developing anti-poisoning modifications targeting SO 2 competitive adsorption in flue gas.