Comparison of different TiO2 photocatalysts for the gas phase oxidation of volatile organic compounds.
Gas-solid photocatalyzed oxidation of air contaminants is being explored more and more for possible application to decontamination, purification and deodorization of enclosed atmospheres. Indoor air is characterized by a huge number of pollutants at low concentrations. Volatile organic compounds (VOC) represent the main indoor air pollutants category, and are of great concern since some of them can act negatively on human health. Several treatments exist to reduce VOC concentrations in gaseous effluents, but photocatalytic oxidation appears to be the most appropriate regarding indoor air specific constraints. It is then necessary to develop photocatalysts, which can possibly be used in an application such as indoor air-quality improvement. In the present work, three different TiO2-based materials were studied and compared for the photocatalytic oxidation of a typical pollutant of indoor air: methyl ethyl ketone. Kinetic studies were performed for each material in dry and humid air conditions, and the Langmuir-Hinshelwood model was satisfactorily applied in almost every case. A second approach consisted of determining methyl ethyl ketone degradation by-products. Acetaldehyde was found to be the main gaseous intermediate, and could be taken into account in the general Langmuir-Hinshelwood modeling.
Raillard
C
C
Ecole des Mines de Nantes, GEPEA, UMR CNRS 6144, DSEE, La Chantrerie, 4, Rue Alfred Kastler, BP 20722, 44307 Nantes Cedex 3, France.
Héquet
V
V
Le Cloirec
P
P
Legrand
J
J
D000393:Air Pollutants / Q000302:isolation & purification*; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry*; D007700:Kinetics; D008962:Models, Theoretical; D009812:Odorants / Q000517:prevention & control*; D010084:Oxidation-Reduction; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*
D000393:Air Pollutants; D004396:Coloring Agents; C009495:titanium dioxide; D014025:Titanium