Preparation of molybdenum zeolites from molybdenum hexacarbonyl. 1. Infrared studies

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

DOI:https://doi.org/10.1021/j100233a015· OSTI ID:5854914

Abdo, S; Howe, R F

Ir spectroscopy has been used to study the adsorption and decomposition of molybdenum hexacarbonly (Mo(CO)/sub 6/) in the hydrogen (H) and sodium (Na) forms of zeolite Y. Two forms of adsorbed Mo(CO)/sub 6/ are found in both H-Y and Na-Y: a weakly (physically) adsorbed complex and a more strongly perturbed species. On being heated in vacuo above room temperature, the adsorbed Mo(CO)/sub 6/ decomposes. In H-Y, three distinct subcarbonyl species are formed reversibly. At temperatures of 200/sup 0/C or higher, decarbonylation is irreversible, and oxidation of the molybdenum occurs, as indicated by loss of zeolite OH groups and appearance of oxomolybdenum species. Carbon monoxide (CO) chemisorbed on oxidized molybdenum sites gives a characteristic ir band at 2170 cm/sup -1/. Ir evidence is presented for interaction of ammonia with intra-zeolitic molybdenum cations. Surface area, X-ray diffraction, and low-frequency infrared measurements indicate that the zeolite crystallinity is retained on heating in vacuo up to 500/sup 0/C, but loss of structure occurs on heating in oxygen at high temperature. In Na-Y, a single subcarbonyl species is formed reversibly upon initial decomposition of adsorbed Mo(CO)/sub 6/. At higher temperatures metallic molybdenum appears to be formed which does not adsorb appreciable quantities of CO. The resistance of the MoNa-Y to oxidation by O/sub 2/ depends on the temperature of prior activation.

• Research Organization: Univ. of Wisconsin, Milwaukee
• OSTI ID: 5854914
• 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
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
DATA
DECOMPOSITION
DIFFRACTION
EXPERIMENTAL DATA
HIGH TEMPERATURE
HIGH VACUUM
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
INFRARED SPECTRA
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IONS
MATERIALS
MINERALS
MOLYBDENUM COMPOUNDS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PRESSURE DEPENDENCE
REACTION INTERMEDIATES
SAMPLE PREPARATION
SCATTERING
SEPARATION PROCESSES
SORPTION
SPECTRA
STRUCTURAL CHEMICAL ANALYSIS
SURFACE AREA
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
ZEOLITES