PREPARATION AND PERFORMANCE EVALUATION OF MATERIALS FOR ELECTROCATALYTIC APPLICATIONS

This PhD thesis is devoted to the preparation and characterization of materials for electrocatalytic applications. The focus has been on the surface of electrodes. The physical and chemical structure of surfaces is one of the main variables of electrocatalytic properties. In particular, the physical structure of a surface (amorphous vs. crystalline) is often claimed to affect the surface activity of electrocatalysts. Also, the chemical structure (active sites on flat vs. stepped facets) has been claimed to be an essential variable influencing catalysis as well as electrocatalysis. Scrutiny of both situations was performed in our laboratory by preparing a series of transition metals oxides (e.g. Ir, Ru, Ni, Co) used in electrochemically activate electrodes, for the reactions of hydrogen and oxygen evolution. A number of techniques have been used: i) electrochemical (CV, polarization); ii) non electrochemical (XRD, TGA, SEM, EDX). Two novel synthetic methods for the production of metal oxides nanoparticles have been implemented.