| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 72535 | Microporous and Mesoporous Materials | 2015 | 9 Pages |
•High resolution adsorption data was collected for a range of gases.•A detailed thermodynamic assessment was completed.•ETS-10 displays strong adsorption for both quadrupolar and non-quadrupolar gases.•Adsorption characteristics are likely due to the unique crystal structure of ETS-10.
A proposal for the differences in the adsorption characteristic for ETS-10 is created by contrasting the adsorption properties of as-synthesized ETS-10 with 13X and highly siliceous ZSM-5. ETS-10 is a unique structure type in that the walls of the channels where adsorption takes place are made entirely of silica, while the chains of titania octahedra in the structure impart a negative charge that is offset by exchangeable cations; a portion of which intrude into the channels. To determine whether adsorption on Na-ETS-10 is driven predominately by cationic or van der Waals effects, the adsorption affinity for several gases was measured on all three adsorbents. The adsorption mechanism was probed by using the isotherms to calculate the enthalpy and entropy of adsorption as a function of loading and by contrasting the behaviour of ETS-10 against both 13X and highly siliceous ZSM-5. The results of the analysis indicate that ETS-10 has, simultaneously, a high affinity for molecules both with and without strong quadrupole moments. This behaviour is believed to result from a sparse number of highly deshielded cations that exist in the otherwise non-polar channels. This bi-functional nature is borne out of the crystal structure of ETS-10 where the cations are located in discrete bands within the unit cell rather than being uniformly distributed throughout the structure.
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