Facet-Controlled CuO Support Enhances Catalytic Activity of Pt Nanoparticles for CO Oxidation.

The metal-support interaction plays a crucial role in determining the catalytic activity of supported metal catalysts. Changing the facet of the support is a promising strategy for catalytic control via constructing a well-defined metal-support nanostructure. Herein, we developed cubic and octahedral CuO supports with (100) and (111) facets terminated, respectively, and Pt nanoparticles (NPs) were introduced. The characterizations revealed the facet-dependent encapsulation of the Pt NPs by a CuO layer due to the oxidation of the CuO support during the CO oxidation reaction. The CuO layer on Pt at cubic CuO (Pt/c-CuO) significantly enhanced catalytic performance, while the thicker CuO layer on Pt at octahedral CuO suppressed CO conversion. The formation of a thin CuO layer is attributed to the dominant Pt-O-Cu bond at the Pt/c-CuO interface, which suppresses the adsorption of oxygen molecules. This investigation provides insight into designing high-performance catalysts via engineering the interface interaction.