Theoretical study on the reaction mechanism of CO2 hydrogenation to methanol

Hydrogenation of CO 2 is challenging from both economic and environmental view points. In the present study, density functional theory (DFT) method was employed to investigate the reaction mechanism of methanol synthesis from CO 2 hydrogenation. Two possible reaction pathways were proposed, where hydrogenation of CO 2 led to intermediate HOCO free radical, followed by the formation of intermediate HCOOH or CO, finally resulting in the methanol formation. The results showed that the preferred pathway was CO 2 → CO → H 2 CO → CH 3 OH, whose enthalpy energy is −35.389788 kJ/mol. The calculated results of the configuration and the enthalpy energy of classic molecules were in good agreement with the values in literature, which indicated that the results should be reliable.