This paper compares different coating methods (in situ solid combustion, hybrid deposition, secondary growth on seed, suspension, double deposition of wet impregnation and suspension) to deposit Ce0.2Zr0.8O₂ mixed oxides on cordierite substrates, for use as a three way catalyst. Among them, the double deposition was proven to be the most efficient one. The coated sample shows a BET (Brunauer-Emmett-Teller) surface area of 25 m²/g, combined with a dense and crack free surface. The catalyst with a layer of MnO₂-NiO-Co₃O₄ mixed oxides on top of the Ce0.2Zr0.8O₂/cordierite substrate prepared by this method exhibits good activity for the treatment of CO, NO and C₃H₆ in exhaust gases (CO conversion of 100% at 250 °C, C₃H₆ conversion of 100% at 400 °C and NO conversion of 40% at 400 °C).
Keywords: CO; NO; ceria—zirconia; cobalt oxide catalysts; cordierite; manganese; nickel; oxidation; propylene.