Metal Encapsulation-Driven Strong Metal–Support Interaction on Pt/Co₃O₄ during CO Oxidation

The strong metal–support interaction (SMSI), which affects the catalytic performance of supported metal catalysts, plays a central role in the modern chemical industry. However, gaining a fundamental understanding of the SMSI under realistic conditions remains challenging. Herein, we show the evidence of SMSI between Pt and Co3O4 using both three-dimensional and two-dimensional model catalysts. Combined operando techniques reveal the encapsulation of Pt nanoparticles (NPs) by a Co3O4 overlayer during CO oxidation. We show that the presence of Pt–Co3O4 interface by the formation of Co3O4 overlayer on the Pt NPs is the key factor to enhancing catalytic activity, which is confirmed by density functional theory calculations. This work highlights the origin of SMSI and provides an opportunity to design high-performance heterogeneous catalysts.