Cluster Adsorption of CO2 on Activated Carbon Norit RB2 and Metal-Organic Frameworks MOF-177 and MOF-505

Abstract The experimental isotherms of carbon dioxide adsorption by the metal-organic frameworks MOF-177 and MOF-505 and by the activated carbon Norit RB2 at 25°C were interpreted within the framework of the cluster adsorption model. It is shown that CO2 molecules are adsorbed into the first layer of the sorbent in the form of monomers and clusters of different sizes. The equilibrium coefficients of the reactions of formation of monomers and clusters on the sorbent, the monolayer capacity, and the number of molecules in the sorbate clusters, which are the parameters of the cluster model, were determined graphically and by the least squares method. To confirm the cluster nature of adsorption, the criterion of clustering of sorbate molecules introduced in previous works was used.