Toluene oxidation over mesoporous TiO2 in a combined process of wet-scrubbing and UV-catalysis.

Toluene is a representative and toxic contaminant in industry or indoor airs. In this work, a novel and facile method was developed to prepare mesoporous TiO2 for the photo-catalytic oxidation of toluene in a wet-scrubbing reactor. Interestingly, by changing the preparation parameters, including dosage of template material, hydrolysis rate, hydrothermal temperature and calcination temperature, the crystalline phase of catalyst could be partially adjusted among brookite, anatase and rutile. With 30 ppm toluene input, an enhanced toluene removal of 62% and CO2 production of 95 ppm were achieved, while no soluble or particulate byproduct was released. In contrast to traditional photo-catalysis, the UV adsorbing ability of catalyst, the cluster of mesoporous TiO2 and the corresponding structure in micrometer-scale were key to the UV utilization and toluene removal in wet-scrubbing reactor.