Theoretical investigation of CO catalytic oxidation by a Fe–PtSe2 monolayer

Abstract

CO oxidation under mild conditions is investigated computationally for the catalysts based on a single transition metal (Sc–Zn) embedded at the Se vacancy of a PtSe₂ monolayer. The iron-embedded Fe–PtSe₂ monolayer is identified as the most suitable catalyst among the investigated systems. Both, Langmuir–Hinshelwood (LH) and Eley–Rideal (ER) reaction paths were considered for the CO oxidation by adsorbed O₂ molecules and by adsorbed O atoms. The CO oxidation by O atoms bound to Fe–PtSe₂ proceeds via the ER mechanism in a single reaction step with a small activation barrier (21 kJ mol⁻¹). Both LH and ER reaction mechanisms can take place for CO oxidation by adsorbed O₂ molecules. Whereas the barrier for the rate-determining step of the LH reaction path (72 kJ mol⁻¹) is higher than that for the ER path (53 kJ mol⁻¹), the kinetics analysis shows that both processes have comparable rate constants at 300 K. Langmuir–Hinshelwood mechanism becomes dominant at a lower temperature. Results reported here indicate that the Fe–PtSe₂ catalyst can efficiently catalyze CO oxidation under mild conditions.