Visible light photocatalytic oxidation of toluene using a cerium-doped titania catalyst

This paper focuses on the evaluation of the potential to use a cerium-doped titania photocatalyst activated by visible light to destroy volatile organics. Toluene is the model compound employed to test the photocatalyst, which is coated on the inner surface of an annular plug flow reactor. Mass transfer resistances are present and considered. Experiments were conducted over a range of residence times between 1 and 20 s and toluene concentrations between 150 and 600 ppb using constant visible-light intensity at room temperature. It is shown that the reaction kinetics can be approximated by a first-order expression with a reaction rate coefficient of 1.72 ± 0.015 s^-1. The water adsorption coefficient was found to be 2.64 m³/mol. The catalyst also demonstrates mechanical and chemical stability during the course of the experiments conducted. These results indicate that the cerium based titania catalytic surfaces can be considered for application to destruction of volatile organic hydrocarbons in air using a visible light source.