Copper-vanadium-cerium oxide catalysts for carbon black oxidation

Series of V-Ce and Cu-V-Ce oxides with different atomic ratios were prepared by the incipient wetness impregnation of a ceria support. These solids were studied by TG–DTA in the oxidation of a model soot (carbon black (CB) Degussa N330). V-Ce oxides are active in the carbon black oxidation and an increase in the vanadium content enhances their catalytic activity. This observation is correlated with the presence of a V2O5 phase. However, this catalytic system (V-Ce) produces CO during the CB oxidation. Adding copper to the V-Ce oxide to form a ternary system (Cu-V-Ce) has a beneficial effect on the CO2 selectivity. A synergistic effect between copper and vanadium species on ceria is evidenced. The presence of the V2O5 phase on the catalyst enhances the activity for the CB oxidation while copper (II) species decrease the CO production significantly.