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Keratin, obtained from chicken feathers, was grafted on the surface of commercially available carbon nanotubes. The original procedure developed allows a covalent interaction between some specific chemical groups characteristic of the keratin, with some functional groups introduced on purpose on the surface of the nanotubes, as revealed by infrared and Raman spectroscopies, which also allowed to determine structural changes introduced during the process, such as crystallinity, which lead to changes in other properties, as well.

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A novel material, with a general formula of IrSn-Sb-O, was synthesized for use in solid polymer electrolyte water electrolyzers (SPEWEs) by the thermal decomposition of the chloride precursors H 2 IrCl 6 , SnCl 4 Á5H 2 O, and SbCl 3 in ethanol. The material functions simultaneously as an electrocatalyst and support for the oxygen evolution reaction (OER). Two different H 2 IrCl 6 proportions in the reaction mixture were tested to observe the effect of this proportion on the electrocatalytic activity and composition of the materials. Physicochemical properties of Ir-Sn-S-O were characterized by X-ray diffraction, scanning electron microscopy. The electrochemical properties of the materials studied were measured using cyclic voltammetry, linear scan voltammetry, and electrochemical impedance spectroscopy. Mechanical mixtures of IrO 2 with Vulcan carbon or antimony doped tin oxide were also tested with respect to the OER to compare the properties of Ir-Sn-Sb-O. The results indicate that the catalyst-support materials presented nanometric sizes (1-2 nm) and electrocatalytic properties similar to IrO 2 supported on Vulcan carbon but with higher stability toward the oxygen evolution reaction. The synthesized mixed oxides could be a suitable anode material in SPEWEs.

Highly dispersed platinum or platinum-based catalysts on a conductive support are commonly used as electrode materials in low-temperature fuel cells. Similarly, iridium oxide is the usual anode material in polymeric exchange membrane electrolyzers. The performance and, in particular, the stability of these catalysts strongly depends on the characteristics of the support. This study presents the results of the physicochemical and electrochemical characterization of the powers of antimony-doped tin oxide (ATO) synthesized by a chemical coprecipitation method and a minimum calcination time. These supports were used as catalytic supports for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The ATO was characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy, energy dispersive spectrometry and four probe resistivity techniques. The electrochemical properties were obtained by cyclic voltammetry (CV), linear voltammetry (LV) and rotating disk electrode (RDE). The material obtained showed nanometric sizes of 4-9 nm, and the electrochemical results indicate that the synthesized ATO nanoparticles can be used as a support for IrO 2 and Pt in electrodes for PEM electrolyzers and fuel cells. Some mixtures of synthesized ATO and Vulcan carbon (VC) were assayed as mixed supports for ORR and OER and for acquiring a protective effect of ATO on the degradation of the carbon support.

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