Mathematical Modeling of the Hydrogen Evolution Reaction on Pt/C Electrodes Considering Diffusion Effects

摘要

In kinetic studies of various electrochemical reactions carried out using electrochemical impedance spectroscopy technique ( EIS), the classical approach is the use of equivalent circuits to model and adjust the various parameters involved in these reactions. This approach has a number of problems such as loss of physical meaning of the various passive elements (resistors, capacitors and inductors) present in the circuit as well as its connection with the phenomena involved in the process under study. This paper proposes the mathematical modeling of the hydrogen evolution reaction (HER) by considering the diffusive processes of the species H~+ and H_2, using a method of trial and error to fit the model to real data obtained from experiments performed on Pt/C deposited on glassy carbon holding to a rotating disk electrode. The model takes into account kinetic aspects, diffusive and adsorption, allowing the collection of the rate constants for each step of the HER reaction and handling the parameters involved in this reaction. With this method it is possible to observe the changes that this manipulation induces, allowing predictions about the behavior expected of the different systems considered in this work, but subjected to similar tests.