This study investigates the influence of lanthanum (La) doping on the CO2 adsorption behavior of silica-based porous composites synthesized via a chemical solution method. Structural analyses using X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed that crystallization of lanthanum oxide within the amorphous silica matrix progresses with increasing La content. CO2 adsorption measurements revealed that samples with lower La concentrations exhibited higher reversible adsorption capacities at low temperatures, indicating that physical adsorption within microporous structures plays a more dominant role than chemical interactions. Enhancing CO2 adsorption performance requires maximizing the effective active surface area through uniform dispersion of fine lanthanum oxide particles. However, the complex involvement of fluid behavior and thermal expansion at elevated temperatures suggests that temperature-dependent structural design is essential for practical applications.
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