Characterization of mesoporous region by the scanning of the hysteresis loop in adsorption–desorption isotherms

The scanning hysteresis loop provides information about the correlation of the pore network, its connectivity and pore size distribution; nonetheless, this correlation cannot be revealed from the complete isotherm. To analyze the connectivity of the porous network in ordered mesoporous materials modified with iron and cobalt oxides, Ar adsorption–desorption isotherms and their corresponding scanning of the hysteresis loops at three temperatures (65, 77, and 87 K) were measured. Two mathematical models based on the independent domains theory (i.e. Uncorrelated Model (UM) and Partial Correlated Model (PCM)) were applied to adjust the desorption branches in the hysteresis loops associating these results to the connectivity in the porous network and the presence of pore-blocking effects.