A Proposal for the Mechanism of the CH + CO2 Reaction

Author(s)

Vichietti, Rafael ^[1] ; Spada, Rene F. K. ^[2] ; da Silva, Alberico B. F. ^[3] ; Machado, Francisco B. C. ^[1] ; Haiduke, Roberto L. A. ^[3]

Affiliation

^[1] Inst Tecnol Aeronaut, Dept Quim, Praca Marechal Eduardo Gomes 50, BR-12228900 Sao Jose Dos Campos, SP - Brazil

^[2] Inst Tecnol Aeronaut, Dept Fis, Praca Marechal Eduardo Gomes 50, BR-12228900 Sao Jose Dos Campos, SP - Brazil

^[3] Univ Sao Paulo, Inst Quim Sao Carlos, Dept Quim & Fis Mol, Ave Trabalhador Sao Cartense 400, BR-13566590 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: ACS OMEGA; v. 4, n. 18, p. 17843-17849, OCT 29 2019.
• Web of Science Citations: 0

Abstract

Few experimental studies on the CH + CO2 global reaction propose H, CO, and HCO as major products. However, the reaction mechanisms behind this process have not yet been elucidated. Moreover, some intriguing kinetic particularities were noticed in these previous investigations. The advanced theoretical study performed here shows that a CH insertion mechanism is capable of explaining all the experimental data available. Hence, the strong deviations from a traditional Arrhenius behavior ascribed to the rate-determining elementary reaction (the CH insertion step) account for the kinetic particularities observed experimentally. A change in the preferred product channel as temperatures increase (from HCO + CO to H + 2CO) is also predicted to occur due to the HCO decomposition, although the CH depletion rates in typical conditions are not affected by this additional step. (AU)

• FAPESP's process: 19/07671-4 - Theoretical study of molecules in astrophysical environments
• Grantee: Rene Felipe Keidel Spada
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/07707-3 - Excited states and biradicalar nature of poliacenes and periacenes
• Grantee: Francisco Bolivar Correto Machado
• Support Opportunities: Regular Research Grants
• FAPESP's process: 10/18743-1 - Employment of multipoles from the quantum theory of atoms in molecules and kinetic studies in systems found in the interstellar medium
• Grantee: Roberto Luiz Andrade Haiduke
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/05691-5 - Application of quantum chemistry methods in the study of possible routes for formation of small molecular systems in different astrophysical environments
• Grantee: Rafael Mario Vichietti
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/23714-1 - Electronic structure relativistic calculations for evaluation of new prolapse-free basis sets
• Grantee: Roberto Luiz Andrade Haiduke
• Support Opportunities: Regular Research Grants