Flexibility of the zeolite RHO framework. In situ X-ray and neutron powder structural characterization of divalent cation-exchanged zeolite RHO

Journal Article · Wed Jun 06 04:00:00 EDT 1990 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00168a029· OSTI ID:6619947

Corbin, D R; Abrams, L; Jones, G A ^[1]; Eddy, M M; Harrison, W T.A.; Stucky, G D ^[2]; Cox, D E ^[3]

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1. E. I. du Pont de Nemours and Company, Inc., Wilmington, DE (USA)
2. Univ. of California, Santa Barbara (USA)
3. Brookhaven National Laboratory, Upton, NY (USA)

Zeolite RHO has an unusual three-dimensional monolayer surface with a topology that gives equal access to either side of the surface. In the absence of supporting structural subunits, e.g., smaller cages or channels, RHO exhibits atypical framework flexibility with large displacive rearrangements. These have been investigated by in situ X-ray powder diffraction studies of zeolite RHO exchanged with various divalent cations. The unit cell variation (e.g., Ca,H-RHO (400{degree}C), a = 13.970 (5) {angstrom}; Sr-RHO (250{degree}C), a = 14.045 (1) {angstrom}; Ba-RHO (200{degree}C), a = 14.184 (2) {angstrom}; Cd-RHO (350{degree}C), a = 14.488 (3) {angstrom}; Na,Cs-RHO (25{degree}C), a = 15.031 (1) {angstrom}) is a particularly sensitive function of cation and temperature. Rietveld analysis of neutron diffraction data was used to refine the structures of two samples, Ca,ND{sub 4}-RHO and Ca,D-RHO. Ca,D-RHO shows the largest reported deviation from Im{bar 3}m symmetry (a = 13.9645 (7) {angstrom}) for a RHO structure.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6619947
• Journal Information: Journal of the American Chemical Society; (USA), Journal Name: Journal of the American Chemical Society; (USA) Vol. 112:12; ISSN 0002-7863; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
COHERENT SCATTERING
DATA
DATA ANALYSIS
DIFFRACTION
EXPERIMENTAL DATA
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MEASURING INSTRUMENTS
MEASURING METHODS
MINERALS
NEUTRON DIFFRACTION
NUMERICAL DATA
SCATTERING
STRUCTURAL CHEMICAL ANALYSIS
X-RAY DIFFRACTION
ZEOLITES