Construction of a synergistic Pt dual-active site catalyst for promoting low temperature CO oxidation

Abstract

Designing and fabrication of high performance Pt-based catalysts with high atom-utilization efficiency are essential but challenging for CO oxidation. Herein, we have constructed an atomically dispersed Pt-based catalyst, merging Pt single atoms (SA) and Pt atomic clusters (C) into n-type CeO₂ nanoparticle-decorated p-type CoAlO nanosheets with abundant oxygen vacancies, through a facile defect-induced in situ atom deposition strategy. The fabricated Pt/60CeO₂–CoAlO (Pt_SA+C) catalyst presents optimized CO activity, achieving a remarkable TOF_Pt of 0.89 s⁻¹ at 50 °C and 100% CO conversion at 100 °C. Mechanistic studies indicate that the improved performance is due to the synergistic effect of dual Pt active sites. This effect minimizes competitive adsorption between CO and O₂, boosts oxygen activation, and facilitates the concurrent operation of Mars–van Krevelen and Langmuir–Hinshelwood reaction pathways at low temperatures, thereby accelerating CO oxidation kinetics. This study highlights the significant importance of synergistic effects between dual-active sites in enhancing the reaction efficiency, thereby paving the way for the rational design of highly efficient atomically dispersed heterogeneous catalysts.