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Automobile exhaust has been a major cause of air pollution since pollutantemission from gasoline engine powered vehicles is harmful for both human beingsand the environment, and catalytic transforming technology is regarded as one of themost efficient solution for gasoline engine pollution control. Three-way catalyst（TWC） has been widely used to remove CO, NOxand HC to their inactive productsCO2, N2and H2O simultaneously. The typical TWC formulation usually containsnoble metals, such as platinum （Pt）, palladium （Pd）, and rhodium （Rh） as the activecomponents. Pd is relatively economical and more abundant than Pt and Rh, On theother hand, Pd exhibits excellent capability for low-temperature oxidation of carbonmonoxide and hydrocarbons. Therefore, Pd-only TWC has received considerableattention. At the same time, implemented Beijing Ⅴ Standard requires emissionsstandard mileage from100000km to160000km, which requires the catalyst has gooddurability. Therefore, under the premise of ensuring catalytic activity, how to reducethe dosage of precious metal and improve the stability at high temperature with gooddurability are the two problems needed to resolve.In this thesis a novel way independently invented by our laboratory, namedultrasonic-assisted membrane reaction （UAMR）, realized controllable synthesis ofnano-noble metal particles, and the prepared RhAu/γ-Al2O3-UAMR catalystspossessed much higher catalytic activity with low dosage of precious metal. Thereby,we synthesised Pd nanoparticles with uniform particle diameter, good dispersity andCe0.6Zr0.4O2support with high oxygen storage capacity by UAMR method, andinvestigated the various precipitant, such as ammonia water and Ethylen-ediamineeffects on carrier performance. The results have shown that the support prepared byUAMR method, ethylenediamine as precipitant, has higher specific surface area, porevolume and hydrogen consumption, and corresponding three-effect catalyst has betteractivity.As we know, the chemical state, shape, size, distribution of active center in thecatalysts prepared by the impregnation method are difficult to control and easysintering at high-temperature. Herein, a novel one-step precipitation method wasinvestigated, a series of0.5wt%Pd/Ce0.6Zr0.4-xYxO2and0.5wt%Pd/Ce0.6Zr0.4-xPrxO2（x=0,0.03,0.05,0.1） catalysts were prepared. And characterized by X-ray diffration（XRD）, N2adsorption-desorption, transmission electron microscopy （TEM）, hydrogen-temperature-programmed reduction （H2-TPR） and hydrogen consumptionmeasure-ment. The results showed that both fresh and aged catalysts had higherthree-way catalytic activities and hydrothermal stability than the corresponding IMPsamples. The interaction between PdO and carrier was enhanced, and the PdO speciesand the PdO interface Ce4+ reduction was promoted. Appropriate amount of Y and Prdoped were extent improved the thermal stability of the catalysts which were preparedby one-step precipitation method, the oxidation performance of HC wassimultaneously significantly promoted. After hydrothermal aged at900°C,Pd/Ce0.6Zr0.35Y0.05O2and Pd/Ce0.6Zr0.3Pr0.1O2catalysts presented optimal catalyticactivity and the broadest operation window.At last, we investigated for batch preparation nano-particles by UAMR method.
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