[Preparation method of Pd/Ce0.5Zr0.5O2 three-way catalysts]

1% Pd/Ce0.5Zr0.5O2(CZ) catalysts were prepared by deposition-precipitation (DP), mixing (MIX) and conventional impregnation (IMP) methods, and the effects of the preparation methods on the three-way catalytic behaviors were investigated. Hydrogen temperature-programmed reduction (H2-TPR) and in situ diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) were performed to understand the Pd-support interaction and the three-way catalytic reaction mechanisms. The experiments results reveal that the catalyst prepared by deposition-precipitation (DP) method shows the strongest Pd-support interaction and the best light-off performance. In situ DRIFTS results suggest that there exists alternative route of NOx reduction over Pd-DP catalyst. And it is supposed that Pd-support interaction leads to the difference of reaction mechanism and then the diversity of light-off performances.