Photocatalytic oxidation of benzene in air was carried out over TiO2/Sr2CeO4 catalysts. The prepared photocatalyst was characterized by S-BET, UV-vis diffuse reflectance and XPS. TiO2/Sr2CeO4 absorbs much more visible light than TiO2 in the visible light region. The XPS spectrum shows that the binding energy value of Ti 2p(3/2) transfers to a lower value. The main purpose was to investigate the kinetic model and degradation mechanisms. The kinetic data matched well with the Langmuir-Hinshelwood (L-H) kinetic model with the limiting rate constant and the adsorption constant in this case were 0.0064 mg l(-1) min(-1) and 9.2078 l mg(-1), respectively. No gas-phase intermediates were detected by direct GC/FID analysis under the conditions despite the high benzene concentration. Ethyl acetate and (3-methyl-oxiran-2-yl)-methanol were two major identified intermediates which were accompanied by butylated hydroxytoluene, 2,6-bis(1,1-dimethylethyl)-4,4-dimethylycyclohe, 2,5-cyclohexadiene-1,4,dione,2,6-bis(1, 1-dim). It is plausible that at least one of these less-reactive intermediates caused the deactivation of the photocatalyst. Finally, the photocatalytic oxidation mechanisms were speculated.. (c) 2006 Elsevier B.V. All rights reserved.