A novel catalyst material for oxygen evolution electrodes was prepared and characterised by different techniques. IrO2 supported on a SiC-Si composite was synthesised by the Adams fusion method. XRD and nitrogen adsorption experiments showed an influence of the support on the surface properties of the IrO2 particles, affecting the IrO2 particle size. The prepared catalysts were electrochemically characterised by cyclic voltammetry experiments at 25,80,120 and 150 degrees C. In accordance with the observed variation in particle size, a support loading of up to 20% improved the activity of the catalyst. Powder conductivity measurements were also performed, which showed the influence of the support particles in the packing of IrO2 particles, perhaps favouring the formation of channels and pores between particles, thus increasing the catalyst utilisation. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.