2024 AIChE Annual Meeting
(569ed) Ab Initio Sampling of the Free Energy Landscape for Water Splitting Electrocatalytic Reactions Using Iridium Oxides
Author
Lee, E. - Presenter, University of Chicago
The decarbonization of major global sectors is critical in reducing the volume of greenhouse gas emissions, and one promising technology for solving this grand challenge is clean hydrogen. A leading strategy to generate clean hydrogen is water electrolysis, whose kinetics are often limited by the oxygen evolution reaction (OER) process. Iridium (Ir) based catalysts, such as iridium oxides, are the current benchmark for electrocatalysis of OER owing to their superior performance and excellent stability. Previous theoretical investigations have primarily focused on reaction energetics using density functional theory at T=0 K with a limited understanding of the role of thermal and solvation effects on the reaction free energy. Here, I present computational investigation on the chemical processes between iridium oxide surfaces and water under potential bias using ab initio molecular dynamics with enhanced sampling simulations. We analyze the entropic effects due to solvation and finite temperatures by directly calculating the free energy surface of the OER process with and without potential bias. This work presents an essential step in simulations of nanoscale reactions at electrocatalytic interfaces.