Catalytic oxidation of VOCs over Mn/TiO2/activated carbon under 185 nm VUV irradiation.

Volatile organic compounds (VOCs) are regarded as the major contributors to air pollution, and should be strictly regulated. Photocatalytic oxidation (PCO) is of great interest for the removal of VOCs owing to its strong oxidation capability. However, its application is greatly limited by catalytic deactivation. Vacuum Ultraviolet (VUV) irradiation provides a novel way to improve the photocatalytic activity while much O3 will be generated which may cause secondary pollution. In this study, a multi-functional catalyst of Mn/TiO2/activated carbon (AC) was developed to eliminate and utilize O3, as well as enhance catalytic oxidation of VOC degradation via ozone-assisted catalytic oxidation (OZCO). The results indicate that Mn modified TiO2/AC (i.e. 0.1%Mn/20%TiO2/AC) achieved a toluene removal efficiency of nearly 86% with 100% elimination rate of O3. With the help of Mn/TiO2/AC catalyst, O3 was catalytically decomposed and transformed into active species of O (1D) and OH, thus enhancing toluene removal. The combination of VUV irradiation with multi-functional catalyst provides a novel and efficient way for the degradation of VOCs.