Aerogel has been identified as an advantageous support material for functional monolayers due to its stability and high surface area (1200 m²/g). A monolayer of N-[3-(trimethoxysilyl)propyl] ethylenediamine was deposited onto aerogel with supercritical propane, producing a CO₂ sorptive material. The reaction was performed at a temperature of 150 C, a pressure of 7500 psig, and for a duration of 15 minutes. Samples were analyzed with a Brunauer-Emmett-Teller (BET) machine to determine surface area (m²/g) and pore size (Å), and ²⁹Silicon nuclear magnetic resonance (NMR) to verify silane density (silanes/nm²). A monolayer with approximately 2 silanes/nm² of surface coverage and a post-reaction BET area of 500 m²/g and pore size of 300 Å has been reproducibly made.