Developing effective methods for carbon dioxide capture has become one of the major goals of researchers due to the relationship between global climate change and rising atmospheric carbon dioxide levels. In industry, the current state of the art is the use of liquid amine scrubbers. However, supported solid amine sorbents have been investigated due to their advantages such as low heats required for sorbent regeneration, high capture capacities, and less costly operation compared to volatile amine scrubbers. Our group has widely investigated the role of the pore system in the final mechanism of carbon dioxide capture and the interaction between amine molecules and the pore system. When the amine occupies too much available pore space, we find that the diffusion of CO 2 molecules through the pores is significantly more difficult, so the ability of the adsorbent to capture carbon dioxide is reduced. We are testing a new material (NEU-1c) as supported by amine sorbent for CO2 capture. NEU-1c functionalizes with polyethylenimine (PEI). Large PEI molecules may be preferentially accommodated into the large mesopore and macropore networks of NEU-1c. It is expected that NEU-1c-PEI may retain open pores accessible to CO2 diffusion to internal amine sites while supporting more amines. Thus, addressing the trade-off between high amine loading and high amine efficiency.