Open AccessOn the extrema on the potential dependence of the charge transfer resistance in the hydrogen evolution reaction
Author(s) -
В. И. Кичигин
Publication year - 2021
Publication title -
vestnik permskogo universiteta. seriâ himiâ
Language(s) - English
Resource type - Journals
ISSN - 2223-1838
DOI - 10.17072/223-1838-2021-2-154-164
Subject(s) - maxima and minima , kinetic energy , chemistry , adsorption , hydrogen , thermodynamics , reaction rate constant , charge (physics) , chemical physics , analytical chemistry (journal) , kinetics , physics , chromatography , organic chemistry , mathematics , quantum mechanics , mathematical analysis
The shape of the charge transfer resistance Rct versus overpotentialh curves for the hydrogen evolution reaction (Volmer – Heyrovsky mechanism, Langmuir isotherm for adsorbed hydrogen) was analyzed. It was shown that, depending on the kinetic parameters of reaction steps, three cases are possible: (i) there are no extrema on these curves; (ii) there is one maximum; (iii) there are a minimum and a maximum. Some ways for obtaining kinetic parameters from the curves with extrema are discussed. It was shown that the rate constants and transfer coefficients of all steps can be determined from logRct–h curve alone if there are a minimum and maximum of Rct in cathodic region. In the absence of the extrema, the amount of kinetic information gained from logRct–h plots is considerably reduced.