Effect of Framework Charge Density on the Ion Exchange Properties of Zeolites
Members of a group of zeolites such as X and Y differ from each other only in the degree to which aluminium has isomorphously replaced silicon within the framework. As far as ion exchange properties are concerned, the effects of isomorphously increasing the number of aluminiums per unit cell are fou...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SAGE Publications
1984-12-01
|
| Series: | Adsorption Science & Technology |
| Online Access: | https://doi.org/10.1177/026361748400100402 |
| _version_ | 1797283280085581824 |
|---|---|
| author | R. P. Townsend K. R. Franklin J. F. O'Connor |
| author_facet | R. P. Townsend K. R. Franklin J. F. O'Connor |
| author_sort | R. P. Townsend |
| collection | DOAJ |
| description | Members of a group of zeolites such as X and Y differ from each other only in the degree to which aluminium has isomorphously replaced silicon within the framework. As far as ion exchange properties are concerned, the effects of isomorphously increasing the number of aluminiums per unit cell are fourfold: (a) the unit cell volume increases; (b) the framework charge density increases; (c) there is a decrease in the ratio of the number of available crystallographic cationic sites to the number of framework charges on the lattice; (d) the zeolite becomes more hydrophilic. The effects of changing isomorphously the framework charge on the degree of hydrolysis, stability, and selectivity of the zeolite are discussed. The problems of attempting to correlate changes in selectivity with bulk properties of zeolites is first considered and then experimental data on hydronium exchange, the sodium/ammonium exchange in faujasites and lead exchanges in faujasites are presented. With respect to the latter, the limitations of dielectric theory are emphasized. |
| first_indexed | 2024-03-07T17:29:45Z |
| format | Article |
| id | doaj.art-165d1e69526245cbba28dc791e87fb1d |
| institution | Directory Open Access Journal |
| issn | 0263-6174 2048-4038 |
| language | English |
| last_indexed | 2024-03-07T17:29:45Z |
| publishDate | 1984-12-01 |
| publisher | SAGE Publications |
| record_format | Article |
| series | Adsorption Science & Technology |
| spelling | doaj.art-165d1e69526245cbba28dc791e87fb1d2024-03-02T18:12:37ZengSAGE PublicationsAdsorption Science & Technology0263-61742048-40381984-12-01110.1177/026361748400100402Effect of Framework Charge Density on the Ion Exchange Properties of ZeolitesR. P. TownsendK. R. FranklinJ. F. O'ConnorMembers of a group of zeolites such as X and Y differ from each other only in the degree to which aluminium has isomorphously replaced silicon within the framework. As far as ion exchange properties are concerned, the effects of isomorphously increasing the number of aluminiums per unit cell are fourfold: (a) the unit cell volume increases; (b) the framework charge density increases; (c) there is a decrease in the ratio of the number of available crystallographic cationic sites to the number of framework charges on the lattice; (d) the zeolite becomes more hydrophilic. The effects of changing isomorphously the framework charge on the degree of hydrolysis, stability, and selectivity of the zeolite are discussed. The problems of attempting to correlate changes in selectivity with bulk properties of zeolites is first considered and then experimental data on hydronium exchange, the sodium/ammonium exchange in faujasites and lead exchanges in faujasites are presented. With respect to the latter, the limitations of dielectric theory are emphasized.https://doi.org/10.1177/026361748400100402 |
| spellingShingle | R. P. Townsend K. R. Franklin J. F. O'Connor Effect of Framework Charge Density on the Ion Exchange Properties of Zeolites Adsorption Science & Technology |
| title | Effect of Framework Charge Density on the Ion Exchange Properties of Zeolites |
| title_full | Effect of Framework Charge Density on the Ion Exchange Properties of Zeolites |
| title_fullStr | Effect of Framework Charge Density on the Ion Exchange Properties of Zeolites |
| title_full_unstemmed | Effect of Framework Charge Density on the Ion Exchange Properties of Zeolites |
| title_short | Effect of Framework Charge Density on the Ion Exchange Properties of Zeolites |
| title_sort | effect of framework charge density on the ion exchange properties of zeolites |
| url | https://doi.org/10.1177/026361748400100402 |
| work_keys_str_mv | AT rptownsend effectofframeworkchargedensityontheionexchangepropertiesofzeolites AT krfranklin effectofframeworkchargedensityontheionexchangepropertiesofzeolites AT jfoconnor effectofframeworkchargedensityontheionexchangepropertiesofzeolites |