CuO, K2O and V2O5 supported on ceria-titania: Synthesis, characterization, and application on diesel soot combustion

Abstract

Diesel soot oxidation with CuO/V2O5/K2O/CeO2-TiO2 catalyst samples at a ratio of 1:1 was studied. Mixtures of the catalyst with diesel soot lowered the oxidation temperature from 601 to 427 oC. The soot oxidation study on TG / DTA showed that the K-Cu-V modification improved the low temperature activity in air. Sample-B with 12.5% K2O was the most active with a peak activity at 427 oC. Further the activity improvement was accomplished with the incorporation of K-Cu-V, attributed to the mobility of potassium on melting. Chemical interactions between the K2O and titania resulted in potassium titanate formation. In addition the XRD patterns obtained for samples C and D loaded with higher concentrations of K showed the formation of solid solutions with the oxides of Ce, K and V. Nevertheless, the variation of K content had a limited effect on soot ignition temperature. The catalyst with a 12.5 wt.% of K2O, 7.5 wt.% of V2O5 and 2 wt.% of CuO exhibited a complete combustion at (Tmax) 427 oC.