(234a) 3-Dimensional Disordered Silica As a Dual Pore Amine Functionalized Sorbent for Carbon Dioxide Adsorption
Recent work in the capture of carbon dioxide on porous solids has focused on how to increase capture capacity and capture speed, in order to make these materials more applicable to industrial conditions. One popular method is to load amine groups onto these porous supports, for instance onto zeolite or metal organic framework sorbents. While these materials can show high capacities with enough amine group loaded onto their surface, there is a tradeoff that exists between capture speed and amine loading, which occurs because the pores where amine is impregnated into the support is often the only channel available for gas diffusion. In order to overcome this challenge we have begun investigating sorbents that contain multiple pore channels which can be preferentially loaded with amines via size selection, allowing for a material which contains high contents of amine groups but still retains fast diffusion speed. One material, known as 3-Dimensional Disordered Silica, is composed of agglomerated spheres of zeolite beta that when loaded with polyethylenimine show fast capture kinetics and high capacities. We have shown that this material can be preferentially loaded in either the micropores present within spheres, or mesopores between spheres, allowing for an increased control in the pore-amine interaction and resulting capture performance.