Photocatalytic Oxidation of Formaldehyde Vapour Using Amorphous Titanium Dioxide


Anastasiya Nikolenko and Boris Melnykov

The gas-phase photocatalytic oxidation of formaldehyde over illuminated amorphous titanium dioxide was investigated using a model flow reactor with the following experimental conditions: 0.1–0.5 l/min flow rate and an organic compound concentration range of 0.006–0.082 mol/m3. Mathematical model of the process which includes two sequential stages: formation of formic acid and its subsequent oxidation to CO2 was offered. It was found that when the amount of TiO2 on carrying agent (anodized titanium) is 3.6 mg/cm2, the intensity of UV lamp is 18 W and the catalyst temperature is 293 K, values of observed rate constants are equal to 6.5.10−3 s−1 for the first stage and 1.10−2 s−1 for the second stage of oxidation. The apparent activation energy of photocatalytic oxidation process of formaldehyde vapour for temperature interval 293 – 323 K is 20.2 kJ/mol.

[1] Carp O., Huisman C. and Reller A.: Progress in Solid State Chemistry, 2004, 32, 33.
[2] Dibble L. and Raupp G.: Catal. Lett., 1990, 4, 345.                                                                     
[3] Alberici R. and Jardim W.: Appl. Catal. B, 1997, 14, 55.
[4] Wang S., Ang H. and Tade M.: Environ. Int., 2007, 33, 694.
[5] Huang B. and Saka S.: J. Wood Sci., 2003, 49, 79.
[6] Xiao X., Liao D. and Zhang H.: Front. Chem. Eng. China, 2007, 1(2), 178.
[7] Qing Y., Fen G., Ying Х. et al.: Huanjing Kexue, 2005, 26, 35.
[8] Tsevis A., Spanos N., Koutsoukos P. et al.: J.Chem. Soc., Faraday Trans., 1998, 94, 295.
[9] Emanuel N. and Knorre D.: Chemical Kinetics: Homogeneous Reactions. Wiley, New York 1973.
[10] Arana J., Dona-Rodriguez J., Garrida-Cabo C. et al.: Appl. Catal. B, 2004, 53, 221.
[11] Parfit G. and Rochester K. (Eds.): Adsorbziya iz Rastvorov na Poverhnostyah Tverdyh Tel. Mir, Moskwa 1986.