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 IrO2 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.