Thermodynamics of adsorption of carbon dioxide on different metal oxides at temperatures from 313 to 353 K and pressures up to 25 MPa

This paper presents adsorption isotherm data of CO2 on four different metal oxides. Absolute adsorption isotherms of CO2 at 313 K on WO3 and at T = 313 K, 333 K, 353 K on CeO2, TiO2 and Al2O3 and pressures up to p = 25 MPa were determined from CO2 excess adsorption isotherms. It was found at 313 K a maximum absolute loading of 0.3 mmol g-1 for WO3, of 1.7 mmol g-1 for CeO2, of 3.1 mmol g-1 for TiO2 and of 6.3 mmol g-1 for Al2O3. All adsorption isotherms were fitted to the Freundlich, Langmuir, Pade`, Sips and Toth models and the Pade ` model present a better fitting than the other models. Based on these data, the Pade ` and the Langmuir model were used to determine the isosteric enthalpy of adsorption which was found to be dependent on the loading and the used model.