Intercalation in montmorillonite of molybdenum cations containing the Mo/sub 6/Cl/sub 8/ cluster core

Journal Article · Wed Oct 01 04:00:00 EDT 1986 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(86)90067-8· OSTI ID:6954830

Christiano, S P; Pinnavaia, T J

Molybdenum cations containing the Mo/sub 6/Cl/sub 8/ cluster core have been intercalated in montmorillonite. cluster ions of the type (Mo/sub 6/Cl/sub 8/(H/sub 2/O)/sub 6-n/(OH)/sub n/)/sup (4-n)+/ were formed by argentometric titration of (Mo/sub 6/Cl/sub 8/)Cl/sub 4/ x 2H/sub 2/O to remove the four terminally bonded chlorines. At pH = 1.5 the clusters occupy the gallery region between the silicate layers of montmorillonite by displacement of Na/sup +/. The cluster intercalates mainly as monopositive cations (n = 3), along with some dipositive cations (n = 2). The maximum cluster loading (80 mmoles/100 g) exceeds the value expected on the basis of ion exchange alone (60 mmoles/100 g). The gallery height of 7.3 A for the new intercalate is compatible with the C/sub 4/ axis of the Mo/sub 6/Cl/sub 8/ core being oriented perpendicular to the silicate layers. Thermolysis of the intercalated clusters at 240/sup 0/C results in the oxidation of the intercalated clusters to molybdenum oxide. Cluster decomposition is accompanied by the collapse of some galleries, while others remain propped open by 3.9 A. The latter value corresponds to two layers of oxygen in the galleries. Thus the oxide is nonuniformly distributed on both the internal and external surfaces of the clay. Complete gallery collapse is observed at 300/sup 0/C.

• Research Organization: Michigan State Univ., East Lansing
• OSTI ID: 6954830
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 64:3; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ABSORPTION SPECTROSCOPY
CHALCOGENIDES
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DECOMPOSITION
DIFFRACTION
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
HEATING
HIGH TEMPERATURE
HYDRATES
HYDROLYSIS
INFORMATION
INFRARED SPECTRA
LYSIS
MOLYBDENUM CHLORIDES
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PH VALUE
REFRACTORY METAL COMPOUNDS
SCATTERING
SOLVOLYSIS
SPECTRA
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA
X-RAY DIFFRACTION
YIELDS