Catalytic oxidation of benzene over nanostructured porous Co3O4-CeO2 composite catalysts

Mesostructured Co₃O₄-CeO₂ composite was found to be an effective catalytic material for the complete oxidation of benzene. The Co₃O₄-CeO₂ catalysts with different Co/Ce ratios (mol/mol) were prepared via the nanocasting method and the mesostructure was replicated from two-dimensional (2D) hexagonal SBA-15 and three-dimensional (3D) cubic KIT-6 silicas, respectively. All the obtained Co₃O₄-CeO₂ catalysts exhibited the similar symmetry with the parent silicas and well ordered mesostructures. The Co₃O₄-CeO₂ catalysts with 2D mesostructure showed lower catalytic activities than the corresponding 3D materials. The Co₃O₄-CeO₂ catalyst nanocasted from KIT-6 and with the Co/Ce ratio of 16/1 possessed the best catalytic benzene oxidation activity due to larger quantities of surface hydroxyl groups and surface oxygenated species. The mesostructured Co₃O₄-CeO₂ material thus shows great potential as a promising eco-environmental catalyst for benzene effective elimination.