Electrochemical Reaction Kinetics at Constant Interfacial Potential

Abstract

Electrocatalysis has been recognized as one of the key technologies toward a carbon-neutral cycle of energy and substances. The rational design of electrocatalysts is undoubtedly the most important approach for accelerating the application of electrocatalysis. Computational screening of electrocatalysts based on thermodynamic evaluation is an efficient method for initially estimating their catalytic performances. However, the reaction rate at the electrochemical interface can be affected by many kinetic factors. Recently, we have developed a method for modeling potential/pH dependence in electrocatalysis, namely, electric field controlling constant potential (EFC-CP), which is much cheaper compared to the widely used grand canonical density functional theory calculations. This method can explicitly determine the evolution of real transition structures at varying potentials. As a result, both the chemical and electrostatic contributions to potential-dependent properties can be explicitly analyzed. Meanwhile, the change of the intermediate dipole along reaction coordinates can also be studied, which can reflect the pH dependence of the kinetic barrier. In this Perspective, we review the significant progress in understanding reaction kinetics in the application of electrochemical nitrogen fixation, ammonia synthesis, and denitrification. These insights can effectively help us understand the underlying physics of electrocatalytic reactions and improve the capability of catalyst design and modification. It is anticipated that the synergy between thermodynamic estimation and kinetic validation will enable the rational design of electrocatalysts in working condition.