Theoretical study of activation Fe–O bond of FeO by CO in the gas phase

The entire reaction mechanism for the gas phase CO–CO₂ conversion by FeO⁺ is discussed by means of the density functional theory and the intrinsic reaction coordinate approach. The calculated results have strongly indicated that the reaction of is a spin-forbidden reaction between the quartet and the sextet potential energy surfaces (PESs). There is a crossing point between the quartet and the sextet potential energy surfaces which may play a significant role in this reaction, by which the activation energy can be decreased from −15.1 to −56.4 kJ mol⁻¹ at the reaction system.