Theoretical Study on Pt1/CeO2 Single Atom Catalysts for CO Oxidation

Abstract

Optimizing the structural configurations of atom-efficient single-atom catalysts (SACs) is crucial for enhancing the catalytic performance. In this study, we used density functional theory (DFT) to investigate single Pt atoms positioned at step-edges and within a solid solution on the CeO₂(111) surface, comparing their thermodynamic stability, electronic properties, and potential energy surfaces for CO oxidation. Stability studies indicate that the solid solution catalyst is more stable than the step-edge-supported catalyst. Additionally, the Pt atom in the solid solution effectively activates lattice oxygen, facilitating oxygen vacancy formation. CO oxidation, analysed through the Mars-van Krevelen mechanism, reveals that the solid solution catalyst possesses moderate CO adsorption energy and lower oxygen vacancy formation energy, resulting in reduced energy barriers throughout the CO oxidation cycle. These findings underscore the critical impact of Pt atom configuration within the CeO₂ matrix on catalytic activity, with the solid solution model demonstrating superior efficiency over step-edge-supported Pt catalysts.