PhotocatalyticTreatmentofAir: HowtodealwiththeproblemofTiO 2 deactivation

In this study photocatalytic oxidation of toluene, used as model VOCs in the gas phase on different types of Ti-based catalytic materials was investigated. The objective of this work was to find out additional information regarding activity and stability of catalyst during photocatalytic treatment of the polluted air. Two designs of the photoreactor were used: classical type of an annular reactor and annular reactor with recirculation. All measurements were performed at room temperature, atmospheric pressure and at constant initial toluene concentration, relative humidity and total flow rate of the reaction mixture. Some experiments were carried out with catalysts thermally treated on different temperatures (350–450 °C). It was found out that thermal treatment of deactivated photocatalyst at higher temperature is efficient method of TiO 2 reactivation. According to results presented in this paper problem of catalyst deactivation can be partially solved by using annular reactor with recirculation of one part of reaction mixture entering the reactor.