Kinetic Aspects of the Electrochemical Reduction of Uranyl in HCl Solutions
Kinetic Aspects of the Electrochemical Reduction of Uranyl in HCl Solutions
The interfacial mechanism of uranyl electroreduction at Au-electrodes in HCl solutions was discussed on the light of systematic studies of cyclovoltammetry, normal pulse voltammetry, UV-vis spectroscopy and published electroanalytical research. Voltammetric waves were numerically deconvoluted on the basis of a reaction model consisting of a first masscontrolled, quasi-reversible first electron transfer and a subsequent reduction of interfacial U(V) intermediate species with adsorption of generated U(IV) products. The dependence of the kinetic parameters on [HCl] indicates an electron transfer following an inner-sphere type mechanism assisted by electrosorption of chloride ligands. The interfacial accumulation of chloride exerts a strong electrostatic repulsion of complexed uranyl and a consequent edged drop of electron transfer rates at [HCl] ∼ 0.5 mol l-1. The electron transfer steps are followed by a chemical desorption reaction of the unstable tetravalent uranyl in U(H2O)94+ species. It is shown that the numerical reproduction of voltammetric waves suits as a method for calculating kinetic parameters in multi-steps electrochemical reactions.
Keywords: Cell proliferation; Cyclic voltammetry; Electron transitions; Gold compounds; Reaction intermediates; Interfacial mechanism
-
Journal of the Electrochemical Society 169(2022)1, 016510
Online First (2022) DOI: 10.1149/1945-7111/ac3e7c
Downloads
- Open Access Version from iopscience.iop.org
- Secondary publication expected
Permalink: https://www.hzdr.de/publications/Publ-34307