PEI-functionalized SCM-37 Zeolite Nanosheets for Efficient CO2 Adsorption

Solid amine adsorbents offer a promising route for carbon capture, yet the performance is frequently limited by poor amine dispersion and slow CO 2 transport when loaded on conventional supports. Herein, we report a high-performance solid amine adsorbent based on a two-dimensional (2D) FER -type zeolite nanosheet, SCM-37, synthesized via a simplified direct route with a markedly increased external surface area and a high density of terminal silanol groups, which serves as a highly accessible platform for polyethyleneimine (PEI) functionalization. Subsequent modification with 1,2-butylene oxide (BO) optimizes the amine environment and enhances hydrophobicity. The optimized BO-PEI/SCM-37 composite exhibits enhanced CO 2 uptake under both dry and humid conditions, while maintaining over 97% of its initial capacity after repeated cycles. Fixed-bed breakthrough experiments further demonstrate prolonged CO 2 capture under both dilute (1 vol%) and simulated flue gas (15 vol%) conditions. In situ DRIFTS and CO 2 -TPD reveal that the open nanosheet architecture promotes uniform PEI dispersion and efficient ammonium carbamate species, thereby improving both adsorption capacity and cyclic stability. These results establish readily synthesized 2D zeolite nanosheets as scalable supports for high performance amine-functionalized CO 2 capture across realistic operating conditions.