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.