Low content Pt-doped CeO2 and core-shell type CeO2/ZrO2 model catalysts; microstructure, TPR and three way catalytic activities

Abstract Core-shell type CeO 2 /ZrO 2 (csCZ) support was investigated as a novel item for reducing platinum content in three way catalysts (TWC). A composite csCZ support was characterized by X-ray diffraction, scanning transmission electron microscopy and energy dispersive spectroscopy. The analysis revealed that the dispersed phase of CeO 2 appeared to form a relatively thin layer and aggregates on the surface of ZrO 2 . Pt-concentrated areas and agglomerate were stabilized on the areas that were Ce-rich on ZrO 2 core particle. The H 2 -TPR profile of Pt/csCZ with Pt content of 0.1 and 0.01 wt.% showed single peak in each reaction temperature, demonstrating extremely active than those of Pt/CeO 2 -NPs, when the same low content Pt loading samples were compared. 0.1 wt.% Pt/csCZ showed better activity than that of 0.1 wt.% Pt/CeO 2 , and TWC activities of low content Pt catalyst are enhanced by designed nanostructured core-shell type CeO 2 /ZrO 2 support. The agglomeration of Pt will be inhibited due to the separated morphological feature of CeO 2 NPs on ZrO 2 , which bring an important effect of csCZ support on Pt reduction.