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|Title:||Adsorption on smooth electrodes: A radiotracer study|
|Author(s):||Rice-Jackson, Lesa Mae|
|Doctoral Committee Chair(s):||Wieckowski, Andrzej|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Adsorption on solids is a complicated process and in most cases, occurs as the early stage of other more complicated processes, i.e. chemical reactions, electrooxidation, electroreduction. The research reported here combines the electroanalytical method, cyclic voltammetry, and the use of radio-labeled isotopes, soft beta emitters, to study adsorption processes at smooth electrodes. The in situ radiotracer method is highly anion (molecule) specific and provides information on the structure and composition of the electric double layer. The emphasis of this research was on studying adsorption processes at smooth electrodes of copper, gold, and platinum. The application of the radiotracer method to these smooth surfaces have led to direct in-situ measurements from which surface coverage was determined; anions and molecules were identified; and weak interactions of adsorbates with the surface of the electrodes were readily monitored.
Adsorption of acetic acid and pyridine molecules were reported on platinum and gold electrodes. The results showed weak interactions of both molecules with gold while pyridine was found to be strongly adsorbed on platinum.
Anion adsorption on the metals, specifically sulfate/bisulfates anions, presented several similarities: the anion adsorption was inhibited by the formation of surface oxides; the adsorption was potential and concentration dependent; and in the potential region preceded by hydrogen evolution, the anions were completely discharged from the surface of the electrodes. Extended measurements on underpotential deposited copper and cadmium on gold and copper, respectively, both showed significant enhancement of the anion adsorption in potential regions where the UPD substrate occurred.
This research provides chemical and electrochemical information about adsorbing species, and helps to extend the theory of electrochemical adsorption on other noble metals and catalytic surfaces.
|Rights Information:||Copyright 1990 Rice-Jackson, Lesa Mae|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9114386|