Photocatalytic degradation of volatile organic compounds (VOCs) with Pt-loaded TiO(2) 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 TiO(2) was rapidly deactivated by the formation of byproducts. The combination of sunlight concentrator and Pt-TiO(2) 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-TiO(2) were analyzed by using UV lamp and electric heater. Acetaldehyde is thermocatalytically degraded by photodeposited Pt on TiO(2) at 70-190 degreesC without UV irradiation, however the UV irradiation is necessary for the complete oxidation of acetaldehyde into CO(2). It is inferred that the degradation of VOCs is enhanced by the combined effect of Pt thermocatalyst and Pt-TiO(2) photocatalyst. (C) 2004 Elsevier Ltd. All rights reserved.