Thermal-stability of Cordierite Catalyst Supports Contaminated By Fe2o3, Zno and V2o5

Abstract

The effect of pollution of diesel particulate filters on their thermal and chemical stability has been studied. Commercial cordierite supports were contaminated, separately, by Fe2O3, ZnO and V2O5, and their evolution after thermal treatment in the range 800-degrees-C to 1200-degrees-C was followed by XRD and SEM. The presence of Fe2O3 had little effect, whereas V2O5 reacted completely even at the lowest studied temperature, giving crystalline silica and aluminium and magnesium vanadates; the formation of a zinc silicate, a zinc aluminate with spinel structure and a glassy phase was observed above 1000-degrees-C in ZnO-contaminated samples. The differences in reactivity and nature of the reaction products were explained taking into account the low melting point of V2O5 and its acidic character. The microstructural changes were correlated with the mechanical properties of the supports