Theoretical study of the dissociation of CO₂ catalyzed by Cr/Ti-doped graphene

In order to screen the highly efficient catalyst for the reduction of CO₂ molecule, the B3LYP method in combination with the 6-31G(d) basis set was used to calculate the adsorption of CO₂ molecule on surfaces of the Cr-doped graphene and Ti-doped graphene. Meanwhile, the CO₂ dissociation mechanism catalyzed by the Cr-doped graphene and Ti-doped graphene was also considered with the same calculation method. Results show that the process is exothermal for the CO₂ adsorption on the doped-graphene surface. The adsorption energies are 28.3 kcal/mol and 7.7 kcal/mol for the CO₂ adsorption on the Cr-doped graphene and Ti-doped graphene surface, respectively. The dissociation of CO₂ catalyzed by the Cr/Ti-doped graphene follows the insertion-elimination mechanism. The calculated activation energies of the C-O bond dissociation are 15.5 kcal/mol and 7.8 kcal/mol for the Cr and Ti-doped graphene, respectively. Our calculation results would be a guideline for the design of catalyst for the CO₂ reduction. (authors)