First-Principles Calculations for Electrochemical Reaction Modeling: An Introduction to Methods and Applications

First-principles calculations based on density functional theory (DFT) play an essential role in state-of-the-art studies aimed at understanding electrochemical reactions and designing corresponding electrode materials. These calculations can be applied to determine the geometric and electronic structures of materials, evaluate the barriers for reactant adsorption and subsequent reactions, and explore reaction mechanisms from a microscale perspective, and they have recently emerged as a popular approach in many electrochemistry-related fields, such as electrocatalysis and batteries. In this chapter, we present an overview of the first-principles calculation approach with an emphasis on providing a pedagogical introduction of its applications in understanding electrochemical processes. First, some physical and mathematical concepts relating to DFT are presented. Next, we turn to a discussion of how to investigate microscale electrochemical processes using DFT calculations. Some practical methods and processes for simulating real systems with computational models are also described. Finally, we provide some examples to demonstrate the power of first-principles calculations in electrochemical studies. Our aim is to give beginners an overview of this approach and a practical guide for its application to electrochemical reactions.