TY - JOUR
T1 - Photocatalytic oxidation of acetonitrile in gas-solid and liquid-solid regimes
AU - Augugliaro, Vincenzo
AU - Palmisano, Leonardo
AU - Loddo, Vittorio
AU - Garcia Lopez, Elisa Isabel
AU - Marci', Giuseppe
AU - Faga, Maria Giulia
AU - Loddo, Vittorio
AU - Martra, Gianmario
AU - Coluccia, Salvatore
AU - Addamo, Maurizio
AU - García-López, Elisa
AU - Augugliaro, Vincenzo
AU - Marcì, Giuseppe
AU - Palmisano, Leonardo
AU - Addamo, Maurizio
PY - 2005
Y1 - 2005
N2 - Il programma NON mi ha consentito di scaricare il PDF di questo articolo. Se lo volete ditemi come inviarloABSTRACTPhotocatalytic degradation of acetonitrile was carried out in both gas–solid and liquid–solid regimes using two commercial TiO2 catalysts(Merck and Degussa P25). For the gas–solid regime, a continuous annular photoreactor was used. The influence on photodegradation kineticsof the gas flow rate and concentrations of acetonitrile, oxygen, and water was investigated. Acetonitrile degradation products detected in thegas phase included carbon dioxide and hydrogen cyanide. The same photoactivity was exhibited in the presence and in the absence of watervapour. The liquid–solid regime used a batch photoreactor with an immersed lamp (the same as for the gas–solid regime). The oxidation productsdetected in the solution were cyanide, cyanate, nitrite, nitrate, methanoate, and carbonate ions. The Langmuir–Hinshelwood kinetic model fitthe photoreactivity data obtained in both regimes and allowed us to determine the rate constant and equilibrium adsorption constant values. Theadsorption constant and kinetic constant value were lower in the liquid–solid regime than in the gas–solid regime. The Merck catalyst had highervalues of these parameters for both regimes than the Degussa P25 catalyst. An evaluation of the possible competition between acetonitrile andwater molecules for the surface sites of the photocatalyst (Ti4 + ions and hydroxyl groups) revealed that for high H2O/CH3CN ratios, as is typicalfor the photo-oxidation process carried out in a liquid/solid regime, acetonitrile molecules were not able to provide a specific interaction with thesurface sites of TiO2, remaining dissolved in the interface water molecular layers. In contrast, for low H2O/CH3CN ratios, as is typical for thephoto-oxidation process carried out in a gas–solid regime, acetonitrile could win the competition with water for surface hydroxyls. 2005 Elsevier Inc. All rights reserved.
AB - Il programma NON mi ha consentito di scaricare il PDF di questo articolo. Se lo volete ditemi come inviarloABSTRACTPhotocatalytic degradation of acetonitrile was carried out in both gas–solid and liquid–solid regimes using two commercial TiO2 catalysts(Merck and Degussa P25). For the gas–solid regime, a continuous annular photoreactor was used. The influence on photodegradation kineticsof the gas flow rate and concentrations of acetonitrile, oxygen, and water was investigated. Acetonitrile degradation products detected in thegas phase included carbon dioxide and hydrogen cyanide. The same photoactivity was exhibited in the presence and in the absence of watervapour. The liquid–solid regime used a batch photoreactor with an immersed lamp (the same as for the gas–solid regime). The oxidation productsdetected in the solution were cyanide, cyanate, nitrite, nitrate, methanoate, and carbonate ions. The Langmuir–Hinshelwood kinetic model fitthe photoreactivity data obtained in both regimes and allowed us to determine the rate constant and equilibrium adsorption constant values. Theadsorption constant and kinetic constant value were lower in the liquid–solid regime than in the gas–solid regime. The Merck catalyst had highervalues of these parameters for both regimes than the Degussa P25 catalyst. An evaluation of the possible competition between acetonitrile andwater molecules for the surface sites of the photocatalyst (Ti4 + ions and hydroxyl groups) revealed that for high H2O/CH3CN ratios, as is typicalfor the photo-oxidation process carried out in a liquid/solid regime, acetonitrile molecules were not able to provide a specific interaction with thesurface sites of TiO2, remaining dissolved in the interface water molecular layers. In contrast, for low H2O/CH3CN ratios, as is typical for thephoto-oxidation process carried out in a gas–solid regime, acetonitrile could win the competition with water for surface hydroxyls. 2005 Elsevier Inc. All rights reserved.
KW - Photocatalysis
KW - Volatile organic compounds
KW - air purification
KW - Photocatalysis
KW - Volatile organic compounds
KW - air purification
UR - http://hdl.handle.net/10447/18091
M3 - Article
VL - 235
SP - 209
EP - 220
JO - Journal of Catalysis
JF - Journal of Catalysis
SN - 0021-9517
ER -