ELECTRODEPOSITION AND CHARACTERIZATION OF METALS FOR IMPROVED CORROSION RESISTANCE AND ENERGY CONVERSION

Until today, research on the electrodeposition topic has developed a broad range of solutions for the obtainment of coatings of different elements, compounds, and alloys, but some issues related to the deposition of certain metals, and the electrochemical stability and safety of the relative plating baths are still unresolved. The present research work was focused on two main topics, both related to the development of electrodeposition processes, and the characterisation of the obtained coatings: a) Electrodeposition and characterisation of palladium films as catalyst (Anodic) layers in Direct Ethanol Fuel Cells (DEFCs). b) Electrodeposition and characterisation of aluminium metal films from Ionic Liquids (ILs); Both the addressed topics have a high industrial relevance in the field of energy production, but they have needed two slightly different approaches to the study of the involved phenomenon. The work on the electrodeposition from ionic liquids was, in fact, part of an European project (SCAIL-UP, HTTP:/scailup.eu) for the scaling up of the aluminising operation from ionic liquids, from a lab scale set-up to an industrial process. The final objective of this project was, in fact, the production of a pilot plant for the aluminization process via ionic liquids of turbine vanes for energy and aerospace applications. My work on this topic mainly focused on technological and industrial aspects of electrodeposition, in the research of the optimal deposition conditions to obtain metallic layers with specific properties (thicknesses, corrosion resistance and morphology). On the other hand, the study and characterisation of Pd surfaces for alcohol reactions in alkaline Direct Ethanol Fuel Cells (DEFCs) had a more fundamental science footprint. This research focused mainly on the improvement of an analytical technique used in high fluence X-Ray sources (Synchrotrons), and on the development of electrodeposition methodologies for the preparation of ordered metallic layers usable as model catalytical coatings for the study of alcohol electrooxidation. Particular focus was paid on palladium, a promising metal for the anodic reactions in Alkaline Direct Alcohol Fuel Cells (DAFCs). Two main electrodeposition techniques were used to control the amount of deposited palladium: the Electro-Chemical Atomic Layer Deposition (E-ALD) and the Surface Limited Redox Replacement (SLRR). Part of this work was carried out during two experiments at the European Synchrotron Radiation Facility (ESRF) in Grenoble during the last year, performed by X-Ray Absorption Spectroscopy (XAS). In the end, both the addressed research topics exploited state of the art deposition and characterization techniques to study the obtained metal coatings. The ability to precisely control deposit coverage and thicknesses via E-ALD and SLRR, the possibility to electrodeposit metals from “exotic” electrolytes like ionic liquids and the use of in situ synchrotron techniques to characterize the obtained metallic films could permit, in future, to design and prepare new materials and devices of great industrial interest, to overcome today’s manufacturing limitations.