CO₂ activation at Au(110)-water interfaces: An ab initio molecular dynamics study

Area of Science:

• Electrochemistry
• Surface Science
• Computational Chemistry

Background:

• Electrochemical reduction of carbon dioxide (CO2) is vital for energy storage.
• Previous simulations often simplify CO2 activation mechanisms.
• Explicit solvent effects and interfacial dynamics are often overlooked.

Purpose of the Study:

• To investigate CO2 activation at gold-water interfaces using advanced computational methods.
• To elucidate the atomic-level mechanisms of CO2 adsorption and desorption.
• To understand the role of explicit solvent and electric potential in CO2 electrocatalysis.

Main Methods:

• Ab initio molecular dynamics (AIMD) simulations.
• Constrained AIMD for reaction pathway exploration.
• Thermodynamic integration for energy calculations.
• Bader charge analysis for electron transfer investigation.

Main Results:

• CO2 adsorption on Au(110)-water interfaces was simulated under reducing potentials.
• Calculated reaction free energy (0.26 eV) and activation energy (0.61 eV) for CO2 adsorption.
• Identified first-electron transfer to CO2 as the critical step, forming adsorbed CO2- anion.

Conclusions:

• Explicit water solvent and interfacial effects significantly influence CO2 activation.
• The formation of the CO2- anion is the initiating step for CO2 electrocatalytic reduction.
• This work provides atomic-level insights into CO2 electrocatalysis at metal-water interfaces.