I. Chronoamperometry and Chronopotentiometry with Unshielded, Circular, Planar Electrodes. II. Applications of Potential Step Chronocoulometry. III. Faradaic Integration of the Diffuse Double Layer

Citation

Lingane, Peter James (1966) I. Chronoamperometry and Chronopotentiometry with Unshielded, Circular, Planar Electrodes. II. Applications of Potential Step Chronocoulometry. III. Faradaic Integration of the Diffuse Double Layer. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/S5G2-TP76. https://resolver.caltech.edu/CaltechTHESIS:11292011-085122446

Abstract

The first portion of this dissertation demonstrates both theoretically and experimentally that the chronoamperometric and chronopotentiometric constants obtained with unshielded, circular, planar electrodes are of the form

[...]

Higher order terms appear to be unimportant under normal experimental conditions (1,2).

The second portion presents the results of detailed calculations of "working tables" for double potential step chronocoulometry applied to the study of first-order chemical reactions of the form

[...]

The final sections discuss the results of chronopotentiometric and chronocoulometric experiments conducted in the presence of "insufficient" supporting electrolyte. It is shown that the observed chronopotentiometric E-t curves should be distorted by the sum of "liquid junction" and "iR_u" voltages. Doublet chronopotentiometric waves are observed for the reduction of certain transition metals. The measured chronopotentiometric constant increases at high current densities and this is interpreted in terms of the reaction of electroactive material in the diffuse layer. It is shown that the residual uncompensated resistance in solutions of low concentrations of supporting electrolyte introduces sufficiently large uncertainties in the potential step chrono- coulometric Q-t^½ intercepts as to invalidate this technique under these conditions.

A least-squares analysis of chronopotentiometric data for the estimation of adsorption statistics according to three common models is described and the listing of a suitable Fortran IV computer program is included.

Extensive tables are calculated for the amount of a doubly charged ion in the diffuse double layer as a function of the concentration of the singly charged indifferent electrolyte.

(1) Anal. Chem., 36, 1723 (1964).

(2) J. Phys. Chem. , 68, 3821 (1964).

(3) J. Electroanal. Chem., in press (1966).

(4) J. Electroanal. Chem. , 10, 284 (1965).

Thesis Files