Accessing Structural Network Features in Disordered Mesoporous Materials via Gas Sorption Measurements

Gas sorption is the most widely employed experimental technique for structural characterization of mesoporous materials (pore sizes between 2 and 50 nm), yet its potential to probe interpore connectivity is limited by an incomplete understanding of pore network effects on phase equilibria. Here, we model the pore space of a mesoporous material employing statistically disordered Bethe lattices with random distributions of pore sizes and interpore connectivities and apply a statistical-thermodynamic framework to analyze sorption behavior during adsorption and desorption. Our results reveal that, in addition to conventional pore size distributions, the average interpore connectivity can be reliably extracted from gas sorption data. Furthermore, we show that sorption isotherms are largely insensitive to other topological details of pore space organization. The findings of the present study clarify which structural parameters govern sorption responses and expand the utility of gas sorption for probing simultaneously pore size distribution and average interpore connectivity in mesoporous materials.