Solid-state cesium-133 NMR studies of cations in Cs/Li/Na zeolite A: An example of cation dynamics involving three sites

Journal Article · Thu May 30 00:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100164a059· OSTI ID:5954501

Ahn, M K ^[1]; Iton, L E ^[2]

---

1. Indiana State Univ., Terre Haute (United States)
2. Argonne National Lab., IL (United States)

{sup 133}Cs NMR spectra show marked changes in the line shape as a function of temperature for a fully hydrated zeolite. A sample containing a mixture of Li{sup +}, Na{sup +}, and Cs{sup +} ions. A single Lorentzian peak is observed at temperature above 285 K, and three resolvable peaks are observed at temperatures below 268 K. These three peaks arise from the Cs{sup +} ion at the sites of the single eight-membered ring (S8R), the single six-membered ring (S6R), and the {alpha}-cage sites near the four-membered rings. The experimental line shapes are satisfactorily simulated by the modified Bloch equations that include the chemical exchange kinetics between these three sites. The analysis yields a lifetime, {tau}, of 0.12 ms for the Cs{sup +} at S8R site at 297 K. The Arrhenius plot yields an activation energy of 44 kJ/mol for the site-exchange process of the charge-balancing Cs{sup +} ions. The exchange between the S6R and S8R sites is considered to be the elementary step of the Cs{sup +} diffusion process.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5954501
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 95:11; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ZEOLITES
NUCLEAR MAGNETIC RESONANCE
SURFACE PROPERTIES
ACTIVATION ENERGY
ARRHENIUS EQUATION
CATIONS
CESIUM
CESIUM 133
DIFFUSION
EXPERIMENTAL DATA
HYDRATION
LIFETIME
LITHIUM
MATHEMATICAL MODELS
SODIUM
SOLIDS
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
THEORETICAL DATA
TIME DEPENDENCE
ALKALI METAL ISOTOPES
ALKALI METALS
CESIUM ISOTOPES
CHARGED PARTICLES
DATA
ELEMENTS
ENERGY
EQUATIONS
INFORMATION
INORGANIC ION EXCHANGERS
INTERMEDIATE MASS NUCLEI
ION EXCHANGE MATERIALS
IONS
ISOTOPES
MAGNETIC RESONANCE
MATERIALS
METALS
MINERALS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
RESONANCE
SILICATE MINERALS
SOLVATION
STABLE ISOTOPES
TEMPERATURE RANGE
400201* - Chemical & Physicochemical Properties