Abstract
• Defective PtX 2 ( X = S, Se, Te) is an excellent structure for supporting Pt atom. • Pt 1 /PtTe 2 has high catalytic activity for CO oxidation. • The electronegativity of X atoms changes the O 2 capture ability of the substrate. • Defective monolayer TMDs can serve as excellent substrates for SACs. The geometric stability, electronic structure and catalytic properties towards CO oxidation of a single Pt atom supported on PtS 2 , PtSe 2 , PtTe 2 with a S, Se, and Te vacancies (Pt 1 /PtX 2 ) were systematically explored by density functional theory calculations. The results showed that the single Pt atom can be located at the vacancy site stably, providing accessible active sites for CO oxidation. Both the Langmuir-Hinshelwood (LH) mechanism and the termolecular Eley-Rideal (TER) mechanism were considered comprehensively. By comparing the rate-determining step (RDS) of CO oxidation process, we found that the LH mechanism is easier to achieve. Meanwhile, as the X atom changes from S to Te, the RDS energy barrier gradually decreases, which is attributed to promoted adsorption and activation of O 2 molecules on Pt 1 /PtX 2 . The results show that Pt 1 /PtTe 2 is the most active catalysts with a low RDS barrier of 0.41 eV. This work provides an important reference for the design of single atom catalysts (SACs) based on transition metal dichalcogenides (TMDs), and has profound implications for the use of supported SACs on defective TMDs for CO oxidation or other reactions.
Published Version
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