/sup 129/Xe NMR of xenon adsorbed in Y zeolites at 144 K

Journal Article · Thu Sep 08 00:00:00 EDT 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100329a022· OSTI ID:6254974

Cheung, T T.P.; Fu, C M; Wharry, S

/sup 129/Xe NMR spectra of xenon adsorbed in Na-Y, K-Y, Mg-Y, Ca-Y, and B-Y zeolites have been measured as a function of the xenon loading at 144 and 293 K. At low xenon loadings, the /sup 129/Xe chemical shift shows two types of dependence on the xenon density in the supercage: linearly increasing and paraboliclike with a minimum. At 144 K, all the zeolites except Ca-Y have a linear dependence, whereas at 293 K, both Ca-Y and Mg-Y show a paraboliclike curvature. By variation of the rate by which a sample is cooled to 144 K, it is shown that there is only one special adsorption site per supercage in the Y zeolites. In Na-Y, Mg-Y, and K-Y, the site can accommodate one xenon atom while in Ca-Y and Ba-Y, two xenon atoms can share the same site. At 144 K, a gas-liquid phase transition is observed when the xenon loading is between 7 and 9 xenon atoms/cage. The transition is characterized by rapid increase in the chemical shift and collapse of the line width. Before the transition, there are large increases in the line width that may be interpreted as the inhomogeneous broadening due to large fluctuations in the xenon number density in the cages. Measurements at 144 K with high loadings if xenon indicate that the supercage in Y zeolite can hold between 10 and 11 xenon atoms. The resulting chemical shift is between 250 and 270 ppm downfield from the resonance of 2 atm of xenon gas (at 293 K). At even higher xenon loading, the excess xenon condenses on the exterior surface of the zeolite microcrystallite to from solid xenon, which has a chemical shift of 304 ppm downfield.

• Research Organization: Phillips Petroleum Company, Bartlesville, OK (USA)
• OSTI ID: 6254974
• Journal Information: J. Phys. Chem.; (United States), Vol. 92:18
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
XENON
SORPTION
ZEOLITES
SORPTIVE PROPERTIES
CHEMICAL SHIFT
CRYSTAL STRUCTURE
ELECTRONIC STRUCTURE
EXPERIMENTAL DATA
MEDIUM TEMPERATURE
XENON 129
DATA
DAYS LIVING RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
FLUIDS
GASES
INFORMATION
INORGANIC ION EXCHANGERS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ION EXCHANGE MATERIALS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MATERIALS
MINERALS
NONMETALS
NUCLEI
NUMERICAL DATA
RADIOISOTOPES
RARE GASES
STABLE ISOTOPES
SURFACE PROPERTIES
XENON ISOTOPES
400201* - Chemical & Physicochemical Properties