Analytical potential energy surface and dynamics for the OH + CH₃OH reaction

Area of Science:

• Chemical Kinetics
• Theoretical Chemistry
• Computational Chemistry

Background:

• Understanding the reaction mechanisms of methanol is crucial for chemical process optimization.
• Accurate potential energy surfaces are essential for reliable dynamics simulations.

Purpose of the Study:

• To develop a new full-dimensional potential energy surface (PES-2022) for the methanol reaction.
• To investigate the reaction dynamics and mechanisms of hydrogen abstraction from methanol.

Main Methods:

• High-level ab initio calculations (coupled-cluster singles, doubles, and perturbative triples-F12) were used to generate the PES-2022.
• Quasi-classical trajectory calculations were performed to study reaction dynamics.

Main Results:

• PES-2022 accurately describes both hydrogen abstraction channels (R1 and R2) and intermediate complexes.
• Simulations at room temperature reproduced experimental observations of vibrational energy distribution in water.
• Dynamics studies at different collision energies suggested distinct mechanisms for the R1 (indirect) and R2 (direct) pathways.

Conclusions:

• The developed PES-2022 provides a reliable tool for studying methanol reaction dynamics.
• The study elucidates the differing mechanisms of the two reaction channels, offering insights into methanol reactivity.