Pt-Cu catalytic coatings for hydrogen combustion: nanostructure and dealloying effects

This thesis work was carried out at Materials Science Institute of Seville, ICMS (Spain). CSIC-Univ.Seville, at the group of nanotechnology, under the supervision of the Prof. Maria Asunción Fernández. The aim of this thesis was to synthesize and characterize supported thin films of metallic nanocatalysts (Pt-Cu) supported on silicon carbide. The nanocatalysts have been produced by a physical vapor deposition (PVD) technique, precisely the magnetron sputtering. One of several possible techniques to check and modify the reactivity of nanocatalysts is the dealloying. The selective leaching in an acid environment was used on nanocatalysts in this thesis. The supported metal alloys produced have been chosen to test on the reaction of Catalytic Hydrogen Combustion (CHC). The work was therefore divided into two parts. In the first the synthesis of the supported metal alloy has been developed, through the use of magnetron sputtering; the second step was the use of the technique of dealloying in acidic environment; the third step was the characterization of the of produced coatings. Through spectroscopic techniques XRD, SEM and EDX. In the second part a process for the CHC reaction on supported nanocatalysts coatings has been developed; after testing the samples, the reported results were used to calculate the activation energy of the reaction CHC and the T50.