Adsorption equilibria of cobalt (III) acetylacetonate (Co(acac)(3)) in the presence of supercritical carbon dioxide (scCO(2)) with methanol co-solvent on MCM-41 mesoporous silica were studied at 313-353 K and 12.5-20.0 MPa from experimental and model calculation viewpoints. The measured data indicated that the amount of the adsorbed metal precursor decreased with increasing pressure and decreasing temperature, which could be explained by CO2 density effects. Correlation by the Dubinin-Astakhov equation was applicable for examining the adsorption equilibria of the metal precursor on the mesoporous silica in scCO(2) while considering the molecular size of the precursor, affinity for the adsorbent, and CO2 density effects. Simulated results with the DA equation implied that the methanol co-solvent can affect the adsorption equilibria of Co(acac)(3) on the MCM-41 adsorbent in scCO(2).