(447a) Amine Loaded Silica Nanomaterials for Advanced Carbon Dioxide Capture

Works dedicated to carbon dioxide capture and conversion on silica sorbents have shown that while these materials can achieve moderate capture capacities and fast diffusion speeds, they cannot outperform the current liquid amine systems employed industrially. In order to overcome these challenges our group and others have investigated the use of amine loaded silica sorbents as carbon dioxide capture systems, where the loaded amines act as chemisorbents to allow for increased selectivity and capacity for CO₂. However, these materials show a significant loss of diffusion speed and amine efficiency at the highest amine loadings, often because the effect that pore-amine interactions have on capture performance have not been investigated. In our work we have used multi-porous silica materials loaded with both tetraethylenpentamine (TEPA) and polyethylenimine  (PEI) amine groups, in order to see what affect these amines will have when loaded onto multi-porous sorbents. We have shown that on MCM-36, which contains multi porous systems that are inaccessible from one another, that amine loading leads to decreases in capture performance due to pore blocking effects. However, when amine is loaded into a 3-D porous sorbent (in this case 3-Dimensional Disordered Zeolite Beta spheres) amine loading can be preferentially placed into the mesoporous channels and allow for quick diffusion to the loaded amine sites through the microporous spheres.