Solid acid catalysts of 12-molybdophosphoric acid (MoP) supported on hydrous zirconia were synthesized using the impregnation method. The solids were characterized by: N-2 adsorption to determine specific surface area and pore size distribution, Thermo-Programmed Desorption (TPD) of NH3 and CO2 were employed for the study of acid and base properties, Raman spectroscopy was used to study the MoP structure, along with P-31 Nuclear Magnetic Resonance and X-ray Photoelectron Spectroscopy. These techniques showed that the heteropolyacid presented intact Keggin structure. The activity of MoP/Z catalysts was measured in the 4-methylpentan-2-ol decomposition. The selectivity to the different products was due to the acid base properties of the samples. 4-methylpentan-2-one product was obtained at low concentration of MoP on ZrO2. (c) 2012 Elsevier Ltd. All rights reserved.