An evaluation of solvent effects and ethanol oxidation

Area of Science:

• Catalysis
• Surface Science
• Computational Chemistry

Background:

• Liquid-metal interfaces are crucial in catalysis, influencing reaction rates, product selectivity, and reaction pathways.
• Understanding these interfaces requires accurate theoretical modeling of solvation effects.

Purpose of the Study:

• To model ethanol oxidation/decomposition on Rh(111) using various solvation approaches.
• To investigate the influence of implicit, explicit, and hybrid solvation models, and water vs. ethanol solvents on reaction energetics and pathways.

Main Methods:

• Density Functional Theory (DFT) calculations.
• Modeling of adsorption, C-C/C-H bond scission, and C-O bond formation.
• Application of implicit, explicit, hybrid, and bond-additivity solvation models.
• Use of water and ethanol as solvents.

Main Results:

• Implicit solvation showed minimal effect on adsorption and reaction free energies.
• Explicit and hybrid models significantly altered free energies, with ethanol solvent having a greater impact than water.
• Preferred C-C scission pathways varied based on solvation model and solvent.
• Bond-additivity model results aligned with trends but were more endothermic.

Conclusions:

• Solvation models critically influence the predicted energetics and reaction mechanisms in catalytic processes.
• Explicit solvation effects, particularly with the reaction solvent, are essential for accurate modeling of liquid-metal interfaces in catalysis.
• The choice of solvation model and solvent is paramount for understanding organic species oxidation/decomposition on surfaces.