Density functional theory (DFT) calculations have been performed to explore the potential energy surfaces of C-O bond activation in CO2 molecule by gas-phase Mo+ cation and Mo atom, in order to better understanding the mechanism of second-row metal reacting with CO2. The minimum energy reaction path is found to involve the spin inversion in the different reaction steps. This potential energy curve-crossing dramatically affects reaction exothermic. The present results show that the reaction mechanism is insertion-elimination mechanism along the C-O bond activation branch. All the theoretical results not only support the existing conclusions inferred from early experiment, but also complement the pathway and mechanism for this reaction.
