Spectroscopic and electrochemical investigations of iodine adsorbed at noble-metal electrodes /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1989.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Studies related with the electrochemistry of the iodine/iodide couple in the aqueous phase have been performed for more than fifty years. However, the corresponding reactivity in the chemisorbed state has not been studied, although it has been known that iodine strongly bound to metal surfaces. The systematic investigation of the chemisorption and electrochemical reactivity of iodine/iodide is invaluable in the overall study of the electrochemical double layer; iodine/iodide represents a model for a strongly chemisorbed supporting electrolyte. Towards this end, the surface electrochemical properties of iodine spontaneously adsorbed at selected polycrystalline (Pt, Au, Ir, Pd, and Ag-plated Pt) and single-crystal Pd(111) noble-metal electrodes were studied using a combination of surface spectroscopic techniques (low energy electron diffraction, Auger, electron spectroscopy, thermal desorption mass spectrometry, and X-ray photoelectron spectroscopy) and thin-layer electrochemical methods (cyclic voltammetry and potential-step coulometry). The major findings include the following: (i) Aqueous iodide is spontaneously and oxidatively chemisorbed as zerovalent iodine atoms in a close packed structure on the subject metals. (ii) Iodine forms a covalent bond with the metal surfaces. (iii) Adsorbate-adsorbate interactions within the close-packed iodine layer are negligible with respect to the iodine-metal bond. (iv) Iodine can be reductively stripped from the electrode surface either by exposure to electrogenerated hydrogen or by application of sufficiently negative potentials. (v) The surface binding strength of zerovalent iodine relative to that of iodide decreases in the order Ag > Au > Pt > Ir. These and other results are discussed in terms of the surface coordination properties of noble-metal surfaces. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Chemistry." |
| Physical Description: | xv, 162 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |