الفهرس 
Fuel Cell’s ComponentsOnly 14 pages are availabe for public view
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Abstract
The results of this thesis are declare in three parts. The first part is concerned with pulsed- current (PC) electrodeposition technique, the second with double- pulse (DP) technique, while the third with a comparison between them. Direct current (DC) technique is also included only for comparison.
Silver nanoparticles are electrodeposited from cyanide-free bath at room temperature by applying PC, DP, or DC electrodeposition techniques and evaluated by cyclic voltammetry (CV) electrochemical methods.
In the first part, the dependence of the electrocatalytic activity of Ag electrocatalyst on PC parameters such as: pulse duty cycle, peak current density, as well as pulse frequency and deposition time for the electrooxidation of ethanol in alkaline media is investigated. The optimum conditions can be achieved at: 60% duty cycle, 50 ,mAcm-2 peak current density, 10 s deposition time and 10 Hz pulse frequency. This is indicated by significantly high ethanol oxidation peak current density (ip) for 30 mAcm-2 and negatively shifted onset potential. The mechanism of ethanol electrooxidation in alkaline media, on Ag/C electrode is accomplished through catalytic role of Ag++ / Ag+ redox species according to the following equations.