Pure CoO(OH), with intra particulate porosity up to 76%, was synthesized by an innovative aqueous precipitation method, starting either from nitrate or sulfate salts. Microstructural and chemical properties were characterized by powder X-ray diffraction (XRD), thermogravimetry (TG) and differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The primary particles (10-15 nm) are self-organized in monolayer building hexagonal nano-platelets (50-200 nm) which are arranged randomly creating large pores. CoO(OH) was converted in Co3O4 by heating in air at 250 degrees C. This treatment did not modify the porosity but increased the specific surface area, which became close to 100 m(2)/g. The catalytic activity for CO and C3H8 total oxidation was better for Co3O4 than for CoO(OH). Besides, at high conversion rate, catalysts prepared from sulfate precursor showed a superior activity for C3H8 oxidation than those prepared from nitrate. This effect can be explained by the improved accessibility of reactants to the surface of the catalysts which exhibit a larger porosity. To our knowledge, the activity values presented here are the highest reported in literature for C3H8 total oxidation. (C) 2013 Elsevier B.V. All rights reserved.