Hydrogen and oxygen isotope exchange reactions over illuminated and nonilluminated TiO/sub 2/

Journal Article · Thu May 21 04:00:00 EDT 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100295a047· OSTI ID:6366079

Sato, S

Hydrogen isotope exchange between H/sub 2/, gaseous H/sub 2/O, and the surface hydroxyls of TiO/sub 2/, and oxygen isotope exchange between O/sub 2/, CO/sub 2/, CO, H/sub 2/O vapor, and the hydroxyls over TiO/sub 3/ were studied at room temperature in the dark and under illumination. Hydrogen isotope exchange between H/sub 2/O and the hydroxyls occurred rapidly in the dark, but the exchange involving H/sub 2/ did not occur at all even under illumination. Oxygen isotope exchange among H/sub 2/O vapor, CO/sub 2/, and the hydroxyls easily took place in the dark, but the exchange involving O/sub 2/ required band-gap illumination. Dioxygen isotope equilibration was much faster than the other photoexchange reactions. Although the oxygen exchange between O/sub 2/ and illuminated TiO/sub 2/ has been considered to involve lattice-oxygen exchange, the present experiments revealed that the hydroxyls of TiO/sub 2/ mainly participate in the exchange reaction. The oxygen exchange between O/sub 2/ and H/sub 2/O vapor was strongly inhibited by H/sub 2/O vapor itself probably because oxygen adsorption was retarded by adsorbed water. Oxygen in CO was not exchanged with the other substrates under any conditions tested.

• Research Organization: Hokkaido Univ., Sapporo, Japan
• OSTI ID: 6366079
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:11; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
400500 -- Photochemistry
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DEUTERIUM
ELEMENTS
EVEN-EVEN NUCLEI
FLUIDS
GASES
HEAVY WATER
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYDROXIDES
ISOTOPE ENRICHED MATERIALS
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
MATERIALS
MEDIUM TEMPERATURE
NONMETALS
NUCLEI
ODD-ODD NUCLEI
OXIDES
OXYGEN 18
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PHOTOCHEMICAL REACTIONS
REACTION KINETICS
STABLE ISOTOPES
TITANIUM COMPOUNDS
TITANIUM HYDROXIDES
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
VAPORS
WATER
WATER VAPOR