Dynamics of molecular hydrogen adsorbed in CoNa-A zeolite
The dynamics of molecular hydrogen adsorbed in the cavities of partially cobalt exchanged type A zeolite (Co/sub 4.1/Na/sub 3.8/-A) has been investigated in the energy range 0-40 meV by incoherent inelastic neutron scattering. Both rotational and vibrational excitations are identified in the spectra. The rotational tunnel splitting of the librational ground state of the adsorbed molecular hydrogen is observed at 3.8 meV. Analysis of the data in terms of a 2-fold cosine potential with two degrees of rotational freedom best accounts for the observed spectral features among several models tested. A barrier height of about 1.4 kcal/mol is calculated. A mode at 15.3 meV is accordingly assigned as a vibration of the bound hydrogen. Evidence for the torsional mode of Al(OH)/sub 4/ complexes, formed in the ..beta..-cages during ion exchange, is found in the vibrational spectra at 21 meV.
- Research Organization:
- Univ. of Maryland, College Park (USA)
- OSTI ID:
- 5994994
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 92:25
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
COBALT COMPLEXES
SORPTIVE PROPERTIES
HYDROGEN
ADSORPTION
SODIUM COMPLEXES
ZEOLITES
BINDING ENERGY
CRYSTAL STRUCTURE
DYNAMICS
INELASTIC SCATTERING
MILLI EV RANGE
NEUTRON REACTIONS
POTENTIALS
ROTATIONAL STATES
VIBRATIONAL STATES
ALKALI METAL COMPLEXES
BARYON REACTIONS
COMPLEXES
ELEMENTS
ENERGY
ENERGY LEVELS
ENERGY RANGE
EV RANGE
EXCITED STATES
HADRON REACTIONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MECHANICS
MINERALS
NONMETALS
NUCLEAR REACTIONS
NUCLEON REACTIONS
SCATTERING
SORPTION
SURFACE PROPERTIES
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
360602 - Other Materials- Structure & Phase Studies