Determining potential dependent activation barriers for elementary electrocatalytic reactions using density functional theory
Open Access
Author:
Regula, Michael John
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Dr. Michael John Janik, Thesis Supervisor Darrell Velegol, Thesis Honors Advisor
Keywords:
Potential Dependent Activation Barriers Electrocatalysis Density Functional Theory Butler-Volmer Kinetics
Abstract:
A method for calculating potential dependent activation barriers for elementary electrocatalytic reactions was studied using density functional theory (DFT) calculations. Reactions involving C-H and O-H bond formation and dissociation and the effects of water solvation on O-H bond formation and dissociation were investigated. Computational methods currently available for calculating electrochemical activation barriers either depend on severe approximations and/or are not transferable to general ion/electron transfer reactions. The proposed method uses a thermochemical approach that determines potential dependent activation barriers for elementary, electrochemical reactions by modeling electrochemical reactions as a two-step mechanism, locating the transition states for analogous non-electrochemical surface reactions, and extrapolating to the solvated, potential dependent system using Butler-Volmer kinetics. Comparing the activation barriers calculated using the proposed method with experimental data suggests that the method is valid. A transferable method for determining potential dependent activation barriers will allow for more educated computational and experimental electrochemical studies, which can potentially improve the efficiency of electrochemical conversion devices.
