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|Title:||Electrochemistry of well-defined rhodium(111) electrode and structural effects in heterogeneous electrocatalysis|
|Author(s):||Hourani, Mohammed Khair|
|Doctoral Committee Chair(s):||Wieckowski, Andrzej|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||This thesis is composed of two parts. The first focuses on the surface electrochemistry of a well-defined Rh(111) electrode, while the second part deals with exploring the crystallographic effects in electrocatalysis.
Basic research was initiated by developing a method for the preparation of well-ordered and clean Rh(111) surface at atmospheric pressure. The resulting surface was characterized in situ by cyclic voltammetry in 0.1 M perchloric acid solution, and by the i-E profiles of silver underpotential deposition. Identical voltammetric data were obtained later using a UHV/electrochemistry transfer system, thereby proving the the reliability of our method.
The voltammetric characteristics of Rh(111) were disclosed for the first time in this study. The following electrochemical investigations were also conducted on the well-defined Rh(111) surface: adsorption of anions and the voltammetric response to their existence in the double layer region, order-disorder transition, and silver underpotential deposition. Additional studies included CO adsorption and electrooxidation, adsorption of oxygen, and adsorption of iodine from the liquid and gas phases.
The second part of the thesis, explores the crystallographic effects in electrocatalysis. This project involved a kinetic study of ethylene electroreduction on crystallographically modified electrodes. Electrochemical techniques were applied to prepare preferentially oriented platinum surfaces. The kinetics and turnover numbers for ethylene reduction on platinum surfaces were extracted from chronoamperometric profiles. The (100) preferential orientation showed 70% higher reactivity than the (111) orientation. The kinetic data, along with the surface crystallography influence on platinum reactivity, were modeled by assuming a rate determining step which involves combination of adsorbed hydrogen and an adsorbed ethyl radical.
|Rights Information:||Copyright 1989 Hourani, Mohammed Khair|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9010893|