The photocatalytic degradation of chlorinated ethanes was studied in a tubular photoreactor packed with TiO(2) pellets prepared by sol-gel method. The steady-state condition was not obtained, but the deterioration in the photocatalytic activity was observed during the irradiation. Effects of mole fractions of water vapor, O(2), and C(2)H(5)Cl or C(2)H(4)Cl(2) and reaction temperature on the photodegradation of C(2)H(5)Cl or C(2)H(4)Cl(2) were examined, and these data were compared with those obtained by the photodegradation of chlorinated ethylenes. On the basis of the products detected with and without oxygen in the reactant's gas stream, we proposed the degradation mechanism. Measurement of diffuse reflectance infrared Fourier transform spectroscopy of pyridine adsorbed on the catalysts showed that decrease in the conversion for the photodegradation of C(2)H(5)Cl was attributable to the formation of Brønsted acid sites. Comparison of the data obtained with the TiO(2) and the sulfated TiO(2) (SO(4)(2-)/TiO(2)) pellets indicated that the photodegradation of C(2)H(5)Cl was suppressed by the presence of the Brønsted sites, but that of trichloroethylene was not affected. Such a difference is attributable to the adsorption process of these reactants on the acid sites on the catalyst surface.
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http://dx.doi.org/10.1021/jp911842t | DOI Listing |
J Phys Chem A
May 2016
Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, Dearborn, Michigan 48128, United States.
The kinetics and mechanism of the reaction of atomic chlorine with ethyl formate [Cl + CH3CH2O(C═O)H, reaction 1] have been examined. These experiments were performed at pressures of 760-950 Torr and temperatures from 297 to 435 K. Reactants and products were quantified by gas chromatography-flame ionization detector (GC/FID) analysis.
View Article and Find Full Text PDFJ Phys Chem A
April 2010
Division of Environmental Science and Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 753-8512, Japan.
The photocatalytic degradation of chlorinated ethanes was studied in a tubular photoreactor packed with TiO(2) pellets prepared by sol-gel method. The steady-state condition was not obtained, but the deterioration in the photocatalytic activity was observed during the irradiation. Effects of mole fractions of water vapor, O(2), and C(2)H(5)Cl or C(2)H(4)Cl(2) and reaction temperature on the photodegradation of C(2)H(5)Cl or C(2)H(4)Cl(2) were examined, and these data were compared with those obtained by the photodegradation of chlorinated ethylenes.
View Article and Find Full Text PDFJ Phys Chem A
December 2008
Department of Chemistry, University of Toronto, 80 St George Street, Toronto, Ontario, Canada M5S 3H6.
Relative rate techniques were used to study the title reactions and determine rate constants of k(Cl + C(4)F(9)CH(2)CH(2)I) = (1.25 +/- 0.15) x 10(-12) and k(OH + C(4)F(9)CH(2)CH(2)I) = (1.
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