Mesoporous Ce-doped ZnO hollow microspheres for oxidation of 1,2-dichlorobenzene

Mesoporous Ce-doped ZnO hollow microspheres were synthesized for the oxidative decomposition of 1,2-dichlorobenzene (o-DCB) as a model compound of polychlorinated aromatic hydrocarbons (PCAHs). The results showed that the molar ratios of Ce/(Ce + Zn) in the hollow microspheres significantly affected their catalytic performances. ZnCe5 hollow microsphere exhibited the best catalytic activity for o-DCB conversion under both dry and humid conditions, which could be attributed to its well-defined hollow structure with abundant amount of mesopores, isolated microspheres, enhanced reducibility and high concentration of surface active oxygen through N2 physical adsorption, H2-TPR and XPS analysis. In situ FT-IR showed that o-DCB could be finally converted into CO2, H2O and HCl via the intermediates of phenolate and catecholate followed by acetate, formate and maleate, which provided us clear understanding on the catalytic mechanism over ZnCe5. This work proved that Ce-doped ZnO hollow materials could be used as promising catalysts for the deep oxidation of PCAHs.