(509h) Core-Shell Nanotextured Composites for Carbon Capture

Sustainable carbon capture, utilization, and sequestration (CCUS) will play a crucial role in achieving carbon neutrality targets. Amine-appended metal–organic frameworks (MOFs) are frequently proposed as candidates for selectively adsorbing CO₂ in carbon capture processes. However, appended-MOF adsorbents designed for strong CO₂ binding often exhibit high affinity for H₂O as well, which compromises their sustainability and stability. Covalent organic frameworks (COFs) represent promising materials for carbon capture alternative due to their high chemical stability, hydrophobicity, and tunable surface groups. In this work, we have developed a “core-shell” nanotextured frameworks where a MOF “core” functions as a CO₂-adsorbing support matrix for amines hosting efficient CO₂ chemisorption. Surrounding the amines is a COF “shell” that provides robust chemical stability and waterproofing properties to the structure. To enhance the core-shell material chemical stability, we employed chemical reactions to achieve amine functionalization, resulting in a high CO₂ capacity at 1 bar. We find that the porous polyamine that entangles the COF significantly enhances CO₂ adsorption. Using quantitative nuclear magnetic resonance (NMR) and density functional theory (DFT), we identified the reaction structures during direct air capture of CO₂ chemisorption, where ammonium carbamate pairs are clearly distinguishable. This work proposes a core-shell-shell design strategy for optimizing materials for point-source and direct air CO₂ capture through further experimental and computational screening.