The synthesized TiO2@IrOx catalyst material was studied thoroughly using different physical characterization methods such as transmission electron microscopy (TEM) (including high-resolution TEM (HRTEM), high-angle annular dark field scanning TEM (HAADF-STEM)), energy dispersive X-ray spectroscopy (EDXS) and electron diffraction (ED), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), X-ray fluorescence (XRF), powder conductivity measurements and N2-physisorption analysis. From the N2-physisorption analysis, the specific surface area was determined using the Brunauer-Emmett-Teller (BET) method. The experimental details of those measurements are given in the electronic supplementary information (ESI). As a reference, the powder conductivity, and the surface area (via N2-physisorption) were also determined for the two commercial catalysts IrOx (Alfa Aesar Premion) and IrO2/TiO2 (Umicore Elyst Ir75 0480).