Facilitating CO oxidation reactivity via potassium intercalation on a single-atom gold catalyst supported by graphite

Heterogeneous single-atom catalysts (SACs) have gained significant attention due to their high catalytic activity and tunable reactivity, which are strongly influenced by the choice of support material. In this study, we employ density functional theory calculations to investigate CO oxidation on Au SACs adsorbed at single-vacancy (SV) sites of various carbon-based materials, including graphene, graphite (Gr), and K-intercalated graphite (K@Gr). Our computational results reveal that K@Gr provides enhanced catalytic stability and activity compared to other carbon-based support materials due to strong electrostatic interactions between intercalated K atoms and the carbon atoms surrounding the Au atom adsorbed at the SV site. The CO oxidation mechanism follows a sequential pathway involving the Langmuir–Hinshelwood and Eley–Rideal mechanisms, in which K@Gr exhibits superior performance in stabilizing key reaction intermediates and thereby provides a more favorable reaction energy profile along the entire reaction pathway. These findings highlight the potential of Gr interaction compounds, such as K@Gr, as promising support materials for SACs, offering both structural stabilization and enhanced catalytic performance through tunable electrostatic interactions.