Preparation and characterization of high performance modified electrodes for the energy devices

Abstract

In order to effectively utilize renewable energy sources, a great challenge need to be overcome, that is the construction of efficient and cheap electrocatalyst. Such catalyst is central to enable wide scale deployment on commercial scale. Since such the catalyst must maintain both high efficiency and durability. some oxides such as IrOx are great catalyst for the energy conversion, but it is rare, expensive and have a weak durability. Consequently, in this thesis the fabricate of low cost electrodes (e.g. Cobalt / graphite) electrodes is the main object of the present work. In addition, the study of synergetic effects between the graphitic support and the deposited Co species. Moreover, the effect of the simultaneous reactions during the electrodeposition of cobalt over the graphite surface and their effect on the final Co/G electrode composition. Different Co/G electrocatalyst electrodes were prepared using electrochemical technique (Chronoamperometry) and a combination between more than one technique (chronoamperometry and cyclic voltammetry) from different baths such as: cobalt chloride bath and Cobalt sulphate bath in absence and presence of complexing agent like citrate ions. The prepared electrodes demonstrated high activity and stability as anode material for alkaline direct ethanol fuel cell (ADEFC) and as catalyst for the oxygen evolution reaction (OER).

Key words: Cobalt, graphite, citrate ions, chronoamperometry, Cyclic Voltammetry (CV), Rotating Ring Disc Electrode (RRDE), Ethanol Oxidation Reaction (EOR), Oxygen Evolution Reaction (OER), Alkaline fuel cells, activation routine.