Volatile organic compounds (VOCs) are attracting more and more attention among all the air pollutants. Photocatalytic oxidation under vacuum ultraviolet (VUV) irradiation presents a novel and promising process for VOC degradation while also generating ozone as a byproduct. To improve the degradation efficiency of VOCs and remove the residual ozone Mn-TiO2/mesoporous CeO2 composite catalysts were developed and used as a catalyst in a VUV-PCO system for toluene degradation. Characterizations including SEM, TEM, BET, XRD, XPS, Raman and H-2-TPR, were conducted to examine the physical and chemical features of the synthetic samples. Results of a toluene degradation test showed that the Mn-TiO2/CeO2 catalyst had superior activity in removing toluene and ozone to Mn-TiO2 and pure CeO2. The toluene removal efficiencies of the catalysts with a different molar ratio of Ti/Ce were found to be in the order of Mn-TiO2/CeO2 (1:1) > Mn-TiO2/CeO2 (1:2) > Mn-TiO2/CeO2 (2:1). The mineralization rate increased in the order of Mn-TiO2/CeO2 (1:1) > Mn-TiO2/CeO2 (2:1) approximate to Mn-TiO2 > Mn-TiO2/CeO2 (1:2) > CeO2 > VUV photolysis. High ozone removal rates of over 99.9% were obtained for all the doped samples with Mn, resulting in a residual ozone lower than 0.12 ppm. With the use of the scavenger tert-butanol (TBA) and the electron spin resonance (ESR) test, hydroxyl radicals ((OH)-O-center dot) were found to play a significant role in toluene oxidation in the VUV-PCO process and ozone is also involved in the formation of (OH)-O-center dot. (C) 2018 Elsevier Ltd. All rights reserved.