Cerium-engineered hierarchical mesoporous silica functionalized with Tetraethylenepentamine (Ce-HMS@TEPA) for high-capacity and recyclable CO2 capture

The consistent rise in atmospheric CO 2 concentrations demands the development of efficient and stable adsorbents for carbon capture technologies. Herein, we report a novel cerium-incorporated hierarchical mesoporous silica functionalized with Tetraethylenepentamine (Ce-HMS@TEPA), characterized and tested under simulated flue gas conditions (10 vol% CO 2 ) to investigate the influence of Ce incorporation and TEPA functionalization on CO 2 adsorption. Strategic Ce incorporation forms Si-O-Ce bonds that boost Lewis acidity, reinforce structural stability, and prevent pore collapse, while facilitating uniform TEPA dispersion. The optimal Ce 0.1 -HMS@TEPA (55.8 %) achieved 3.82 mmol/g CO 2 capacity at an 80 °C/0.15 bar pressure under dry conditions, which was further increased to 4.61 mmol/g under humid conditions. Comprehensive characterization (XRD, BET, TGA) confirmed the preserved pore structure and thermal stability, while the TPD analysis identified distinct CO 2 binding mechanisms. Crucially, Ce-HMS@TEPA retained 93.5 % capacity over 40 cycles (120 °C regeneration), and rapid adsorption kinetics (Avrami model: R 2  > 0.99) outperforming its Ce-free (HMS@TEPA) counterpart. This synergistic interaction of Ce incorporation and TEPA functionalization ensures high CO 2 affinity, rapid adsorption kinetics, and remarkable performance, establishing Ce-HMS@TEPA as a next-generation adsorbent in advancing sustainable carbon capture technologies.