Preparation of molybdenum zeolites from molybdenum hexacarbonyl. 2. Electron paramagnetic resonance studies

Journal Article · Thu May 12 04:00:00 EDT 1983 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100233a016· OSTI ID:5920042

Abdo, S; Howe, R F

EPR spectroscopy has been used to study the adsorption and decomposition of molybdenum carbonyls (Mo(CO)/sub 6/) in the hydrogen and sodium forms of zeolite Y. In hydrogen (H)-Y, decomposition of adsorbed Mo(CO)/sub 6/ at 100/sup 0/C produces a paramagnetic species containing two equivalent Mo nuclei which is tentatively identified as a dinuclear carbonyl radical anion. Decomposition at higher temperatures produces initially a signal attributed to Mo/sup +/, and subsequently three distinct Mo/sup 5 +/ signals. Spin concentration measurements show that up to 50% of the Mo present in the zeolite is observed as Mo/sup 5 +/ following prolonged high-temperature activation. The interaction of oxygen, ammonia, and pyridine with the paramagnetic species has been investigated. In sodium (Na)-Y, no EPR signals are detected upon decomposition of adsorbed Mo(CO)/sub 6/ in vacuo, indicating that zerovalent molybdenum is not oxidized in the absence of zeolite protons. Exposure to oxygen of MoNa-Y activated at temperatures below 300/sup 0/C did cause appearance of Mo/sup 5 +/ signals. 9 figures, 1 table.

• Research Organization: Univ. of Wisconsin, Milwaukee
• OSTI ID: 5920042
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 87:10; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADSORPTION
AMMONIA
AZINES
CARBONYLS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ELECTRON SPIN RESONANCE
ELEMENTS
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HIGH TEMPERATURE
HIGH VACUUM
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
LOW TEMPERATURE
MAGNETIC RESONANCE
MATERIALS
MEDIUM TEMPERATURE
MINERALS
MOLYBDENUM COMPOUNDS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
OXYGEN
PRESSURE DEPENDENCE
PYRIDINE
PYRIDINES
REMOVAL
RESONANCE
SAMPLE PREPARATION
SORPTION
SORPTIVE PROPERTIES
STRUCTURAL CHEMICAL ANALYSIS
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
WATER REMOVAL
ZEOLITES