Abstract
The role of occluded water in the ion exchange selectivity of molecular sieves is studied in detail with Sandia Octahedral Molecular Sieves (SOMS) . SOMS exhibit a high selectivity for divalent cations only when the framework Nb (V) are substituted by M (IV) atoms. Vibrational dynamics of the water molecules of the SOMS with varying charge balancing cations and M atoms are studied by inelastic neutron scattering (INS) measurements. The experimental INS spectra were compared with those of ice Ih to characterize the structural changes induced by confinement on the H2O hydrogen-bonding network. Data indicate that with increasing M (IV) content, a tendency of water molecules to restore the bulk-like arrangements and increased solvation effects on the channel cations [1]. Data are complimented with further characterization by MAS NMR.
| Original language | English |
|---|---|
| Title of host publication | From Zeolites to Porous MOF Materials - The 40th Anniversary of International Zeolite Conference |
| Publisher | Elsevier Inc. |
| Pages | 790-795 |
| Number of pages | 6 |
| Edition | A |
| ISBN (Print) | 0444530681, 9780444530684 |
| DOIs | |
| State | Published - 2007 |
| Externally published | Yes |
Publication series
| Name | Studies in Surface Science and Catalysis |
|---|---|
| Number | A |
| Volume | 170 |
| ISSN (Print) | 0167-2991 |
Funding
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000. This work has benefited from the use of the Manuel Lujan, Jr. Neutron Scattering Center at LANSCE, which is funded by the Department of Energy's Office of Basic Energy Sciences. Los Alamos National Laboratory is operated by Los Alamos National Security LLC under DOE Contract DE-AC52-06NA25396.