Effect of slurry rheological properties on the coating of ceramic honeycombs with yttria-stabilized-zirconia washcoats

Recently, a novel automotive catalyst design, based on the use of palladium supported on yttria-stabilized zirconia (YSZ), was proposed. In the presen t work, the coating of cordierite honeycomb samples with YSZ slurries for t he preparation of such washcoats was investigated. The loading percentage, homogeneity, and reproducibility were found to depend strongly on the slurr y viscosity. Parameters such as the slurry-solids content, pH, type of powd er used, and use and quantity of the dispersants were optimized for the pre paration of stable, low-viscosity YSZ slurries, adjustments that could lead to an efficient coating process for honeycomb structures.