Adsorption of H/sub 2/ isotopes on ZnO: coverage induced ir frequency shifts and adsorbate geometry. Technical report

Technical Report · Mon Feb 01 00:00:00 EST 1982

OSTI ID:5146275

Griffin, G L; Yates, Jr, J T

The coverage dependence of the IR stretching frequencies for dissociative Type I adsorption of H2 and D2 on ZnO powders has been measured using transmission IR spectroscopy. By comparing the frequency shifts observed when the isotopic composition of the adsorbate is varied at constant total coverage with the shifts observed when the total coverage of either pure component is varied, we can separate the dynamic and static contributions to the coverage induced frequency shifts. The ZnH and ZnD shifts are due primarily to electrodynamic interactions. The observed shifts are in good agreement with the Hammaker model for dynamic dipole-dipole interactions, if adsorption is assumed to occur on (2 x 2) reconstructed ZnO (0001) surface planes. In contrast, the OH and OD shifts are due to electrostatic and inductive interactions. The electrostatic contribution can be estimated using a modification of Buckingham's treatment of local environment effects. A qualitative model, based on electron localization effects, is presented to explain the observed inductive contribution.

• Research Organization: National Bureau of Standards, Washington, DC (USA). Surface Science Div.
• OSTI ID: 5146275
• Report Number(s): AD-A-111282/0
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DEUTERIUM
ABSORPTION
HYDROGEN
ZINC OXIDES
SORPTIVE PROPERTIES
ABSORPTION SPECTRA
CHEMICAL COMPOSITION
DISSOCIATION
DYNAMICS
ELECTRODYNAMICS
INFRARED SPECTRA
POWDERS
SPECTROSCOPY
CHALCOGENIDES
ELEMENTS
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
MECHANICS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
OXIDES
OXYGEN COMPOUNDS
SPECTRA
STABLE ISOTOPES
SURFACE PROPERTIES
ZINC COMPOUNDS
400202* - Isotope Effects
Isotope Exchange
& Isotope Separation