Hydrogen on MoS/sub 2/. Theory of its heterolytic and homolytic chemisorption
An atom superposition and electron delocalization molecular orbital study has been made of hydrogen adsorption on MoS/sub 2/. The authors have calculated structures, binding energies, force constants, and frequencies. The most stable chemisorption form is heterolytic at edges of the crystal layers. Reductive homolytic adsorption on the sulfur anion basal planes is predicted to be less stable but is still predicted to occur up to a stoichiometry of H/sub X/MoS/sub 2/ where X approx. 1. For values of X greater than 1, the Mo conduction band is filled to such a level that further reduction by hydrogen becomes energetically unfavorable. H/sub X/MoS/sub 2/ should be a conducting bronze, according to their results. They propose that, under high H/sub 2/ pressures and at sufficiently high temperatures for H to diffuse over the anion surface (a 1.2-eV barrier is calculated), H can diffuse from edge sites out over the basal planes and the edges will be replenished by further heterolytic adsorption. They calculate a basal plane SH bending vibration at 431 cm/sup -1/ and values for edge and corner SH and one MoH edge bond in the 500-600-cm/sup -1/ range, thereby providing an interpretation for the time, temperature-, and pressure-dependent inelastic neutron scattering vibrational spectra of Wright and co-workers.
- Research Organization:
- Case Western Reserve Univ., Cleveland, OH (USA)
- OSTI ID:
- 5277664
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 92:3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Organochromium(III) macrocyclic complexes. Factors controlling homolytic vs heterolytic cleavage of the chromium-carbon bond
H 2 Oxidation Electrocatalysis Enabled by Metal‐to‐Metal Hydrogen Atom Transfer: A Homolytic Approach to a Heterolytic Reaction
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HYDROGEN
CHEMISORPTION
MOLYBDENUM SULFIDES
SORPTIVE PROPERTIES
BINDING ENERGY
CRYSTAL STRUCTURE
INELASTIC SCATTERING
MOLECULAR ORBITAL METHOD
NEUTRON DIFFRACTION
THEORETICAL DATA
VIBRATIONAL STATES
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
DATA
DIFFRACTION
ELEMENTS
ENERGY
ENERGY LEVELS
EXCITED STATES
INFORMATION
MOLYBDENUM COMPOUNDS
NONMETALS
NUMERICAL DATA
REFRACTORY METAL COMPOUNDS
SCATTERING
SEPARATION PROCESSES
SORPTION
SULFIDES
SULFUR COMPOUNDS
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
400201* - Chemical & Physicochemical Properties