Catalysts of 3D ordered macroporous ZrO2-supported core-shell Pt@CeO2-x nanoparticles: effect of the optimized Pt-CeO2 interface on improving the catalytic activity and stability of soot oxidation

摘要

We successfully synthesized 3D ordered macroporous (OM) Pt@CeO2-x/ZrO2 catalysts by a coprecipitation method. This series of catalysts have a well-defined 3D-OM structure. We investigated the activity of the 3D-OM Pt@CeO2-x/ZrO2 catalysts with different shell thicknesses, and systematically studied the adsorption and desorption of NO on the 3D-OM Pt@CeO2-x/ZrO2 via in situ DRIFTS. The 3D-OM support enhances the contact efficiency between the solid reactant and catalyst, while the Pt@CeO2-x coreshell nanoparticles with strong Pt-CeO2-x interaction lead to a larger number of active species. With increasing the Ce/Pt molar ratio, the thickness of the shell becomes larger and the activity of Pt@CeO2-x/ ZrO2 becomes lower. Among the as-prepared core-shell catalysts tested, the 3D-OM Pt1.0@CeO2-x/ZrO2-1 catalyst with the proper thickness of CeO2-x nanolayer shell showed the highest catalytic activity for soot combustion.