Accurate rate constants for elementary reactions of molecular hydrogen and carbon monoxide mixtures and the role of the H-2 rich environment

Author(s)

Vichietti, Rafael M. ; Spada, Rene F. K. ; Machado, Francisco B. C. ; Haiduke, Roberto L. A.

• Document type: Journal article
• Source: Journal of Molecular Modeling; v. 28, n. 8, p. 9-pg., 2022-08-01.

Abstract

This investigation provides accurate rate constant values for a set of elementary reactions relevant to mixtures between molecular hydrogen (H-2) and carbon monoxide (CO) such as syngas. We considered intermediates and products including formaldehyde (H2CO), hydroxymethylene (c-HCOH and t-HCOH) and methanol (CH3OH). The calculations were performed employing the improved canonical variational transition state theory with small-curvature tunneling corrections based on high-level electronic structure results. This study demonstrates for the first time that H-2 can act as an effective catalyst to the reaction from t-HCOH to H2CO. In this case, the adiabatic barrier height for the reaction decreases from 30.6 kcal.mol(-1) to 18.1 kcal.mol(-1) in the presence of H-2. The results obtained here can improve the comprehension regarding processes such as the combustion of hydrogen-rich syngas. (AU)

• 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
• FAPESP's process: 19/25105-6 - Polycyclic aromatic hydrocarbons (PAH's): doping, vacancy, reactivity, excited states: a multiconfigurational approach
• 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: 19/07671-4 - Theoretical study of molecules in astrophysical environments
• Grantee: Rene Felipe Keidel Spada
• Support Opportunities: Regular Research Grants