CO₂ adsorption performances of amine hybrid silica aerogels synthesised via in-situ polymerisation of hybrid precursors

Amine hybrid silica aerogels (AHSAs) were synthesised via a one-step sol-gel method under room temperature, using N-(2-aminoethyl)-3-aminopropyltriethoxysilane (AEAPTES) and tetraethyl orthosilicate (TEOS) as precursors. AHSAs with different amine loadings were synthesised by changing the TEOS/AEAPTES ratio. The specific surface area decreases with amine loading. The highest CO₂ adsorption capacity was achieved when the amine loading was 11.90 mmol/g. The corresponding CO₂ adsorption capacities with simulated air (417 ppm CO₂), 1% CO₂ and flue gas (9.68% CO₂) are 1.86, 3.78 and 5.51 mmol/g, respectively. The amine efficiency of AHSA is up to 0.32. The as-prepared sorbent shows excellent cycle stability. The CO₂ adsorption kinetics were also discussed.