Amine hybrid zirconia/silica composite aerogel for low-concentration CO₂ capture

Amine hybrid zirconia/silica composite aerogel (AHZSA) was prepared via a simple, low-cost and environment-friendly method, i.e. one-pot sol-gel process along with supercritical drying. The pore strucutre, morphology, surface chemistry and CO₂ capture performances of AHZSA were investigated. AHZSA possesses microstructure of the typical aerogels and has a large amount of macropores, which favors the gas diffusion in the pore space. The amine loading and surface amine content of AHZSA is 8.18 and 9.60 mmol/g, respectively. The CO₂ adsorption capacity of AHZSA at 30, 50, 70 and 90 °C in the absence of water vapor is 2.70, 2.10, 2.00 and 1.48 mmol/g, respectively. The CO₂ adsorption capacity at 30 °C increases to 3.40 mmol/g after the introduction of water vapor. Adsorption and desorption kinetics of AHZSA suggest that AHZSA is dynamic for low-concentration CO₂ capture. The adsorbent preparation method is inspiring and the resulting adsorbent is capable, dynamic, and regenerable for low-concentration CO₂ capture.