title: Photocatalytic oxidation of diethyl sulfide vapor over TiO2-based composite photocatalysts.
abstract: Composite TiO2/activated carbon (TiO2/AC) and TiO2/SiO2 photocatalysts with TiO2 contents in the 10 to 80 wt. % range were synthesized by the TiOSO4 thermal hydrolysis method and characterized by AES, BET, X-ray diffraction and FT-IR ATR methods. All TiO2 samples were in the anatase form, with a primary crystallite size of about 11 nm. The photocatalytic activities of the TiO2/AC and TiO2/SiO2 samples were tested in the gas-phase photocatalytic oxidation (PCO) reaction of diethyl sulfide (DES) vapor in a static reactor by the FT-IR in situ method. Acetaldehyde, formic acid, ethylene and SO2 were registered as the intermediate products which finally were completely oxidized to the final oxidation products - H2O, CO2, CO and SO42- ions. The influence of the support on the kinetics of DES PCO and on the TiO2/AC and TiO2/SiO2 samples' stability during three long-term DES PCO cycles was investigated. The highest PCO rate was observed for TiO2/SiO2 photocatalysts. To evaluate the activity of photocatalysts the turnover frequency values (TOF) were calculated for three photocatalysts (TiO2, TiO2/AC and TiO2/SiO2) for the same amount of mineralized DES. It was demonstrated that the TOF value for composite TiO2/SiO2 photocatalysts was 3.5 times higher than for pure TiO2.
authors.affiliation: Boreskov Institute of Catalysis, pr. Ak. Lavrentieva 5, Novosibirsk 630090, Russia. selishev@catalysis.ru.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Selishchev
authors.affiliation: Boreskov Institute of Catalysis, pr. Ak. Lavrentieva 5, Novosibirsk 630090, Russia.
authors.forename: Denis
authors.initials: D
authors.lastname: Kozlov
mesh_terms: D000327:Adsorption; D002245:Carbon Dioxide / Q000737:chemistry; D002384:Catalysis; D007700:Kinetics; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D012822:Silicon Dioxide / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013440:Sulfides / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D013440:Sulfides; D002245:Carbon Dioxide; C009495:titanium dioxide; D012822:Silicon Dioxide; C051751:diethyl sulfide; D014025:Titanium