Abstract:
In this study, the hydrogenation of carbon dioxide (CO
2) to methanol (CH
3OH) over Rh
16/In
2O
3 catalyst was studied through Density Functional Theory (DFT) and microdynamics modeling. The spontaneous dissociation mechanisms of H
2 and CO
2 adsorption at the Rh
16/In
2O
3 interface were investigated. The oxygen vacancies in In
2O
3 enhanced the adsorption process. Bader charge analysis revealed a marginal positive charge on Rh
16, elucidating the critical insights into the electronic characteristics and catalytic activity. The study established the RWGS+CO-Hydro pathway as the predominant mechanism for methanol synthesis, characterized by a sequential transformation of intermediates: CO
2*→COOH*→CO*+OH*→HCO*→CH
2O*→CH
2OH*→ CH
3OH*. Furthermore, degree of Reaction Rate Control (DRC) analysis conducted in the range of 373−873 K and 10
−2 to 10
3 bar identified two principal kinetic phenomena: at lower temperature and higher pressure, the conversion of CO* + H* to HCO* significantly impacted the overall reaction rate. Conversely, at higher temperature, the step from CH
2O* + H* to CH
3O* was dominate.