Degradation of toluene and acetaldehyde with Pt-loaded TiO2 catalyst and parabolic trough concentrator

Photocatalytic degradation of volatile organic compounds (VOCs) with Pt-loaded TiO2 was analyzed at elevated temperatures in the laboratory experiments (40-190 degreesC) and in the field experiments (30-230 degreesC). The temperature of catalyst coated on the sunlight receiver was easily elevated to around 200 degreesC by parabolic trough concentrator (1 m x 1 m). When gaseous toluene (15 ppm) or acetaldehyde (400 ppm) was passed through the reactor, 79% of toluene or 93% of acetaldehyde was removed continuously. In the similar condition, bare TiO2 was rapidly deactivated by the formation of byproducts. The combination of sunlight concentrator and Pt-TiO2 catalyst exhibited the enhancement of complete degradation of VOCs, the inhibition of deactivation, and the reactivation of photocatalyst. The contributions of photocatalytic and catalytic activities of Pt-TiO2 were analyzed by using UV lamp and electric heater. Acetaldehyde is thermocatalytically degraded by photodeposited Pt on TiO2 at 70-190 degreesC without UV irradiation, however the UV irradiation is necessary for the complete oxidation of acetaldehyde into CO2. It is inferred that the degradation of VOCs is enhanced by the combined effect of Pt thermocatalyst and Pt-TiO2 photocatalyst. (C) 2004 Elsevier Ltd. All rights reserved.