Polyethylene glycol/silica and carbon black/silica xerogel composites as an adsorbent for CO₂ capture

Mesoporous polyethylene glycol (PEG)/silica and carbon black (CB)/silica xerogel composites were prepared by the sol-gel method as an adsorbent for CO₂ adsorption. The CO₂ adsorption process was carried out under pure CO₂ atmosphere at room temperature in addition to ambient air. The xerogel composites with high surface area and pore volume showed better CO₂ adsorption capacity than the pure silica xerogel. After modifying samples with propylene diamine using the wet impregnation method, an increase in CO₂ adsorption capacity was observed for the samples except CB/silica xerogel composite. The highest CO₂ adsorption capacity was determined as approximately 0.80 mmol/g for amine modified PEG/silica xerogel composite under pure CO₂ exposure. According to the adsorption-desorption cyclic stability test, it was clear that the stable samples were obtained, which is a desirable property for all CO₂ adsorbents. The promising findings revealed that the xerogel composites can be efficiently used as a CO₂ adsorbent instead of conventional materials in many CO₂ adsorption applications. Additionally, it can be expected that the xerogel composites can provide an effective adsorption process without high-cost, complexity, corrosion, and toxicity problems.