Submonolayer Cu/Pt film as bifunctional catalyst for CO oxidation: An STM study

Considering the high activity in CO oxidation as well as the related reactions, the surface structure of Cu/ Pt bimetallic system and its interaction with CO and O2 molecules have been revisited with low-temperature scanning tunneling microscopy (STM) in combination with density-functional theory calcu-lations (DFT). The extensively concerned Cu/Pt subsurface alloy (Cu-SSA) is clearly demonstrated with relative deactivation to CO and drastically weakened binding to O. In contrast, the submonolayer Cu film on Pt(1 1 1) manifests a significant enhancement in activating the O2 molecules while reserving the strong binding to CO at the uncovered Pt area. Detailed control experiments corroborated by DFT calculations revealed that the Cu/Pt interface serves as the critical sites for both O2 activation and the CO oxidation reaction. Therefore, the submonolayer Cu film may register a more promising catalyst structure than the Cu-SSA configuration for the Cu/Pt bimetallic system. & COPY; 2023 Elsevier Inc. All rights reserved.

Automated summary

The surface structure and interaction of the Cu/Pt bimetallic system with CO and O2 molecules were studied using low-temperature scanning tunneling microscopy (STM) and density-functional theory calculations (DFT). It was found that the Cu/Pt subsurface alloy (Cu-SSA) showed increased deactivation towards CO and weakened binding with O2. In contrast, the submonolayer Cu film on Pt(1 1 1) exhibited enhanced activation of O2 and maintained strong binding with CO. Control experiments and DFT calculations confirmed that the Cu/Pt interface played a critical role in both O2 activation and CO oxidation. Thus, the submonolayer Cu film may be a more promising catalyst structure for the Cu/Pt bimetallic system.