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.

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